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Text to accompany geologic map of the USGS Daytona Beach 30 x 60 minute quadrangle, northeast Florida (Open-File Map Ser...

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 Front Cover
 Table of Contents
 List of Figures
 Abstract and introduction
 Geologic summary
 Lithotratigraphic units
 Hydrogeology and geophysical...
 Derivative products
 References
 Acknowledgement
 Appendix A: FGS wells utilized...
FGS

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STATE OF FLORIDA DEPARTMENT OF ENVIRONMENTAL PROTECTION Herschel T. Vinyard Jr., Secretary REGULATORY PROGRAMS Jeff Littlejohn, Deputy Secretary FLORIDA GEOLOGICAL SURVEY Jonathan D. Arthur, State Geologist and Director OPEN-FILE REPORT 101 Text to accompany geologic map of the USGS Daytona Beach 30 x 60 minute quadrangle, northeast Florida (Open-File Map Series 105) By Richard C. Green, William L. Ev ans, III and Seth W. Bassett 2013 ISSN 1058-1391 This geologic map was funded in part by th e USGS National Cooperative Geologic Mapping Program under assistance award number G12AC20412 in Federal fiscal year 2012

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i TABLE OF CONTENTS List of Figures ............................................................................................................... ............................ ii Abstract ...................................................................................................................... ............................... 1 Introduc tion .................................................................................................................. ............................. 1 Methods........................................................................................................................ ............... 3 Previous Work ................................................................................................................. ........... 5 Geologic Su mmary .............................................................................................................. ..................... 5 Structure ..................................................................................................................... ................. 7 Geomorphology ................................................................................................................. ......... 9 Barrier Island Seque nce District ........................................................................................... 10 Atlantic Coastal Complex ................................................................................................. 10 Lower St. Johns River Valley ........................................................................................... 11 Central Lakes District ........................................................................................................ ... 11 Crescent City Ridge .......................................................................................................... 11 DeLand Ridge .................................................................................................................. 12 Fort McCoy Plain .............................................................................................................. 12 Mt. Dora Ridge ................................................................................................................ 12 Ocklawaha River Valley ................................................................................................... 12 St. Johns River Offset ....................................................................................................... 13 Ocala Karst District .......................................................................................................... ..... 13 Ocala Karst Hills ............................................................................................................. .. 14 Lithotratigraph ic Units ....................................................................................................... .................... 14 Tertiary System ............................................................................................................... ........... 14 Eocene Series ................................................................................................................. ........ 14 Avon Park Formation ........................................................................................................ 14 Ocala Limestone ............................................................................................................... 15 Miocene Series ................................................................................................................ ...... 16 Hawthorn Group ............................................................................................................... 16 Penney Farms Formation ............................................................................................. 16 Marks Head Formation ................................................................................................ 17 Coosawhatchie Formation ............................................................................................ 17 Hawthorn Group (Undifferentiated) ............................................................................ 17 Tertiary/Quaternary Systems ................................................................................................... ... 18 Pliocene/Pleistocene Series ................................................................................................... 18 Cypresshead Formation .................................................................................................... 18 Pliocene/Pleistocene Shelly Sediments............................................................................. 19 Tertiary/Quaternary Dunes ............................................................................................... 19 Pleistocene to Holocene Series ............................................................................................. 20 Anastasia Formation ......................................................................................................... 2 0 Undifferentiated Quaternary Sediments ........................................................................... 20

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ii Quaternary Beach Ridge and Dune ................................................................................... 20 Holocene Sediments .......................................................................................................... 2 1 Hydrogeology .................................................................................................................. ....................... 21 Geophysical Loggin g ........................................................................................................... .................. 21 Stratigraphy and Gamma-Ray Log Interpretation .................................................................... 22 Avon Park Formation ........................................................................................................... 22 Ocala Limestone ............................................................................................................... .... 23 Hawthorn Group ................................................................................................................ ... 23 Pliocene/Pleistocene shelly sediments .................................................................................. 24 Cypresshead Formation and Tertia ry/Quaternary dune sediments ....................................... 24 Derivative Products ........................................................................................................... ..................... 24 References .................................................................................................................... ........................... 25 Acknowledge ments .............................................................................................................. .................. 29 Appendix A: FGS Wells Utilized Fo r Study ...................................................................................... .. 31 LIST OF FIGURES Figure 1. Nearby areas mapped under the FGS STATEMAP Program. ........................................ 2 Figure 2. FGS cores (squares), cut tings (circles) and St. Johns Ri ver Water Management District geophysical logs (triangles) ut ilized for top of rock models See discussion starting on page 14 for lithostrat igraphic unit abbreviations and descriptions. ................................. 4 Figure 3. Location of selected river basins, springs, swallets and other water bodies. .................. 6 Figure 4. Principal subsurface st ructures of north Florida (m odified from Scott, 1988). ............... 8 Figure 5. Terraces in the study area (after Healy, 1975). ............................................................... 9 Figure 6. Gamma Log of W-19451 (see OFMS 105, plate 2, B-B') ............................................. 22

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OPEN-FILE REPORT 101 1 Text to accompany geologic map of the USGS Daytona Beach 30 x 60 minute quadrangle, northeast Florida (Open File Map Series 105) Richard C. Green (P.G. # 1776), William L. Evans, III and Seth W. Bassett ABSTRACT The accompanying 1:100,000 scale geologic map (Open-File Map Series 105, Plate 1) depicts the areal di stribution of bedrock and surficial ge ologic units for the U.S. Geological Survey (USGS) Daytona Beach 30 x 60 minute qua drangle. The map was constructed using a combination of field mapping (at 1:24,000 scale), compilation of data from existing maps (various scales), core and cuttings analyses and descriptions, geophysical log analyses and analyses of various Geographic Information System (GIS) data sources. The resulting data were compiled in ESRI ArcGIS ArcMap™ 10 software for publication as part of the Florida Geological Survey Open-File Map Series. Mapped units range from Middle Miocene to Quaternary. Important resources in the mapped area include potable grou ndwater, springs, sand, clay, and coquina. Numerous springs, swallets (sinking streams), and other karst features are present in the study area. The geologic maps produced for this area not only provide a greater understanding of the interaction between the ge ologic units, associated karst, springs and ecosystems, but have utility as a land manageme nt tool for economic development, mineral and energy production, and environmental protection fo r Florida. Examples include designing new construction projects, siting new water supply wells, energy production facilities, waste management and storage facilities locating sources of mineable resources for aggregate supply, and protection of springs, surface and groundwater quality. Keywords : Florida, geologic map, Avon Park Formation, Ocala Limestone, Hawthorn Group, Penney Farms Formation, Marks Head Formation, Coosawhatchie Formation, Cypresshead Formation, Anastasia Formation, ge omorphology, hydrogeology, springs, swallets, karst, sinkholes, Floridan aquifer system, Flag ler County, Lake County, Marion County, Putnam County, Volusia County, Daytona Beach. INTRODUCTION Florida Geological Survey (FGS) Open-F ile Report (OFR) 101 acco mpanies Open-File Map Series (OFMS) 105, which is comprised of th ree plates. Plate 1 depicts the near-surface geology of the USGS Daytona Beach 30 x 60 minute quadrangle on a digital elevation model (DEM). Plate 2 depicts five geologic cross-sec tions, a stratigraphic co rrelation chart, and representative photos for several of the lithol ogic units in the stud y area. Plate 3 is a geomorphology map on a DEM, showing locations of known springs, sinkholes and swallets, along with photographs of selected exposures wi thin the study area. The study area is located along the Atlantic coas tline of Florida (Figur e 1). It includes the communities of Daytona Beach, DeLand, Flagle r Beach and Ormond Be ach. The quadrangle, which includes portions of Flagler, Lake, Ma rion, Putnam and Volusia Counties, is bounded to the west by the USGS Ocala 30 x 60 mi nute quadrangle, recently mapped under the STATEMAP program (Green et al., 2009a; Green et al., 2009b; Green et al., 2010a; Green et al.,

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FLORIDA GEOLOGICAL SURVEY 2 2010b), to the north by the USGS Saint Augustine 30 x 60 minute quadrangle and to the south by the USGS Orlando 30 x 60 min ute quadrangle (Figure 1). The Tomoka, St. Johns, and Ocklawaha Rivers, along with nu merous creeks and springs, occur in the map area. Recharge to and discharge from the Floridan aquifer system (FAS) occurs throughout the study area. The FAS is the primary source of water for springs and drinking water in the region. One objective for this report is to pr ovide basic geologic information for the accompanying OFMS 105. Information provided by th is report and the plates in OFMS 105 is intended for a diverse audience of professionals in geolog y, hydrology, engineering, environmental and urban planning, and laypersons, all of whom ha ve varying levels of geologic knowledge. The maps can help users identify a nd interpret geologic features which impact activities related to groundwater quality and quantity, as well as aid in locating mineral resources, land-use planning and c onstruction project design. Applie d uses of the maps and data in this report include: 1) identifying potential new mineral resources, 2) characterizing zones of potential aquifer recharge and confinement, 3) aiding water-mana gement decisions on groundwater flow and usage, 4) providing information on aqui fer vulnerability to potential pollution, 5) ecosystem, wetlands and environmenta l characterization, and 6) recreational uses. Figure 1. Nearby areas mapped under the FGS STAT EMAP Program.

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OPEN-FILE REPORT 101 3 Methods Mapping efforts consisted of: 1) reviewing and compiling existing geol ogic literature and data, 2) mapping geologic units in the field at 1:24,000 scale using standard techniques, 3) analyses of existing core and cuttings sample s from the FGS sample re pository, 4) new core drilling, 5) collecting and desc ribing outcrop samples, and 6) preparing a geologic map, geological cross-sections and ge omorphic map of the ar ea. Fieldwork, perform ed during the fall of 2012 through the summer of 2013, consisted of sampling and describing numerous outcrops, river and borrow pit exposures. Forty-three new samples of geologic materi al were added to the FGS surface-sample archives (M-Series) and five cores (1,294 feet or 394.4 meters total) were drilled for the project. Approximately 100 outcrops and exposures were also examined during the project. In addition to new cores collected for this stud y, approximately 350 sets of core s and cuttings archived in the Florida Geological Survey well repository were examined and formation picks were made for mapped geologic units. Over four hundred formation picks derived from geophysical logs (see discussion beginning on page 21 fo r geophysical log interpretation) in addition to the data from the cores and cuttings, were utilized in develo ping various modeled surf aces. Figure 2 shows the locations of FGS cores and cutti ngs and St. Johns River Water Ma nagement District (SJRWMD) data points within the study ar ea. Appendix A includes FGS wells with core and/or cuttings samples which were examined by the authors and used for the top of rock model or for determining the geologic surface and subsurface form ations. An interpolated top of rock surface was developed using kriging along with a Dig ital Elevation Model (DEM) to generate an overburden thickness model. The map and acco mpanying plates were developed in ESRI ArcGIS ArcMap™ 10 software for publi cation as part of OFMS 105. Due to a lack of complete Li DAR coverage in the study ar ea, a custom elevation model was created for this product. Two products were used to create this elevation model: standard LiDAR elevation models with horizontal resoluti ons of five feet (1.5 meters); and a much coarser elevation model based off of topographi c contours with a horizontal resolution of 100 feet (30.5 meters). LiDAR coverage currently exists for the entirety of Lake, Marion, and Volusia counties, in addition to a small portio n of Putnam County alon g the St. John’s River Corridor, and a swath of the coastal areas of Volusia County approximately three miles wide. The majority of both Volusia and Putn am counties lacked LiDAR coverage. The hybrid elevation model was created by first combining all of the existing LiDAR elevation models into a single raster. The coar ser 100 foot (30.5 meter) contour-based DEM was re-sampled and aligned to match the resolution of the five feet (1.5 meter) LiDAR elevation models. A conditional statement was then used in ArcGIS to create a ne w hybrid raster by selecting an elevation value fr om the LiDAR coverage if av ailable; where LiDAR was not available, elevation values were draw n from the coarser, contour based DEM. As a preliminary step, points from each of the datasets (cores, cuttings and geophysical logs) were used to generate a Triangular Irregular Network (TIN) of the modeled surface. This TIN was then used as a method of examining and discarding any points that appeared anomalous compared to their surrounding values. During this step, any point which differed substantially from the surrounding po ints were indicated by a sharp depr ession or peak in the TIN surface; points found that differed by 75 or more feet from surrounding points were then removed from the dataset.

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FLORIDA GEOLOGICAL SURVEY 4 After this step was completed, an ordinary kr iging method was used to generate a top of rock surface using the “stable” algorithm. Lag size was empirically calcu lated based on the total spatial extent of the combined datasets, and then adjusted slightly to improve model performance. The error values for all data were examined after each iteration of the model, and any points with a standardized erro r greater than five or less than negative five were discarded in order to improve the final model performance. Figure 2. FGS cores (squares), cuttings (circles) and St. Johns River Wat er Management District geop hysical logs (triangles ) utilized for top of rock models. See disc ussion starting on page 14 for lithostratigraphic unit abb reviations and descriptions. Much of the study area is blanketed by a veneer of undifferen tiated Tertiary and Quaternary sediments and soils. For this reason, and in keeping with geologic mapping practices developed by Scott et al. (2001) the authors have adopted the policy of mapping the first named geologic unit within 20 feet (6.1 meters) of th e surface. If Tertiary/Quaternary dune (TQd), undifferentiated Quaternary (Qu) Holocene (Qh) or Quaternary beach ridge and dune (Qbd) sediments attain a thickness greater than 20 feet (6.1 meters), then they appear as the mapped unit. If these undifferentiated sediments are less than 20 feet (6.1 meters) thick, then the underlying lithostratigraphic unit appears on the ma p. It is noted that the geologic map (OFMS 105, Plate 1) and geologic cross sections (OFMS 105, Plate 2) may appear to disagree slightly when depicting the upper unit due to this conventi on. This is due to the fact that geologic crosssection contacts are based on straight-line proj ection between wells and thus may lead to apparent thicknesses of units be tween wells that are not supporte d by field evidence or other wells nearby. Parts of the region are heavily vegetated, and pub lic access in several large sections of the mapped area is hindered by the presence of nu merous wetlands, farms, ranches and privately owned land. Additionally, much of the coastal area is heavily develope d with sub-divisions,

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OPEN-FILE REPORT 101 5 many of which are gated communities. In inst ances where access was limited by these factors, the authors had to rely on existing well and core data. Fieldwork access was typically limited to public roads, State-owned la nds and County-owned lands. Previous Work The current study builds on many previous geologic investigations in and around the present map area which were useful in preparin g this report. Prelimin ary county geologic maps for Flagler (Scott, 1992b), Lake (Scott, 1992d), Marion (Scott, 1992e), Putnam (Scott, 1992a), and Volusia (Scott, 1992c) counties at 1:126,720 scal e were previously published by the FGS. However, each of these geologic maps were constr ucted in an average time-frame of two weeks utilizing selected in-house geol ogic data with little-to-no extr a field work. Although these maps provided a starting point for the detailed geologic mapping unde rtaken for this project, significant refinement of prior ge ologic maps was possible as a re sult of this proj ect. A statewide geologic map (Scott et al., 2001) also provided a framework for the current, more detailed mapping. Scott (1988) published detailed descriptions, structure contour maps, and isopach maps for units of the Hawthorn Gr oup. Huddlestun (1988) defined a nd discussed the Nashua and Cypresshead Formations. This study also bene fited greatly from the work performed during geologic mapping of the eastern portion of the US GS Ocala 30 x 60 minute quadrangle (Green et al., 2009a; Green et al., 2009b). Some of the field relationships a nd stratigraphic problems were worked out during those projects and data gathered during work on them proved invaluable to the completion of this project. GEOLOGIC SUMMARY The near surface geology of the USGS 30 x 60 minute Daytona Beach quadrangle is composed of a complex mixtur e of Middle Eocene to Quaterna ry carbonate and siliciclastic sediments. A combination of f actors, including fluvio-delta ic deposition, marine deposition, dissolution of underlying carbonates (karstification), erosion of sediments as a result of eustatic changes in sea level and structur al features have influenced th e geology of th e study area. The oldest unit to crop out in the Dayt ona Beach quadrangle is the Tertiary Coosawhatchie Formation of the Hawthorn Group (T hc). This unit is exposed in the vents of Marion Salt Spring, Juniper Spring and Alex ander Spring (see OF MS 105, Plate 1). Detailed description of the lith ology of all units found in th e study area begins on page 14 of this publication. Along with lithologic descri ptions, several diagnostic foraminifera and echinoids aid in distinguishi ng Ocala Limestone from the Avon Park Formation. The Avon Park Formation contains Cushmania [ Dictyoconus ] americana and Discorinopsis gunteri which are not found in the Ocala Limestone. The occurrence of Nummulites spp. and Lepidocyclina spp. in the Ocala Limestone helps to distinguish it from the Avon Park Formation in the mapped area. Much of the Daytona Beach quadrangle is located within the Ocklawaha, Tomoka, and St. Johns River Basins (Figure 3) There are numerous springs a nd spring-fed rivers within the study area, including two springs in Lake County, thirty-seven springs in Marion County, nine springs in Putnam County and one in Volusia County. These include twelve first magnitude springs and thirty-seven lesser magnitude springs (Scott et al., 2004). A first magnitude spring is defined as having a minimum average flow of at least 100 cubic feet per second (64.6 million gallons per day; Copeland, 2003).

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FLORIDA GEOLOGICAL SURVEY 6 Portions of the recharge ar eas for many of the aforementi oned springs in Lake, Marion, Putnam and Volusia counties are located within the study area. Many of these springs have shown significant increases in pollu tants in the last few decades, particularly nitrate (Phelps, 1994; Phelps, 2004; Jones et al., 19 96; Scott et al., 2002; Upchurch et al., 2004; Copeland et al., 2009). Detailed geologic mapping of li thostratigraphic units in this area provides critical data needed for future assessments of the vulnerab ility of the aquifer systems and springs to contamination. Understanding the surficial geology of the map area is a key factor in developing management and protection plans, not only for th e springs, but for the unconfined portions of the Floridan aquifer system. Figure 3. Location of selected river basins springs, swallets and other water bodies.

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OPEN-FILE REPORT 101 7 Karst processes have extensively modified th e topography of the region, and continue to actively shape it today. Karst topography is ch aracterized by solutional features, subterranean drainage, and caves (Poucher and Copeland, 2006). Do wnward infiltration of slightly acidic rain and surface water through preferen tial pathways, such as joints fractures, and bedding planes, combined with groundwater fluctuations, cause di ssolution of the carbonate rocks (Waltham et al., 2005). The variability of the karst observed within the study area is cl osely related to the thickness of overburden and the presence/abse nce of Cypresshead Fo rmation and Hawthorn Group clays within the overburden mantling the region’s carbonate rocks. Those clays are often the sediments which create a bridge over any cav ities which have formed within the carbonates. The study area can be divide d into two main karst regions : the areas upon the Mt. Dora Ridge and the areas surrounding it. Generally, the overburden sediments are thickest and contain a higher percentage of clay and clayey sediments, resulting more frequently in the occurrence of cover-collapse sinkholes to the we st and south of the Mt. Dora Ridge. To the east of the Mt. Dora Ridge, extending towards the St. Johns River valley, the overburden sediments are generally thinner (see OFMS 105, Plate 2) resulting in both c over-subsidence and cover-collapse sinkholes (Sinclair and Stewart, 1985 ). Several wells examined in this study located on the flanks of the Mt. Dora Ridge exhibited the effects of that in creased karstification. The samples for those wells typically exhibited increased amounts of sa nd, organics and clayey sand interspersed with occasional bits of carbonate rock at depth foll owed by a correspondingly deeper-than-expected top of first carbonate rock unit. One well drilled for this proj ect (W-19453; OF MS 105, Plate 2, cross-section C-C'), demonstrates this. The well had significantly thicker Cypresshead Formation and thinner Hawthorn Group sedime nts than expected. Possible e xplanations include karst or filling in of an erosional lo w in the top of the Hawthorn Group surface. Unfortunately, well control in this area was inadequate to determine the nature of the surface. Structure Several structural features have affected the geology of the region (Figure 4). The Peninsular Arch, a structurally high area which affected depos ition from the Cretaceous to the early Cenozoic, is the dominant subsurface feature of the Florid a peninsula (Applin and Applin, 1944; Applin, 1951; Puri and Vernon, 1964; Williams et al., 1977; Schmidt, 1984; Miller, 1986; Scott, 1997). The axis of the Peninsular Arch, which cuts th rough the western portion of the study area, extends from southeastern Georgia to the vicinity of Lake Okeechobee in southern Florida in a general nort hwest to southeast trend. The crest of the arch passes beneath Alachua County and is highest in Union and Baker counties northwest of the study area. The arch was a topographic high during most of the Cretaceous Period and ha d Upper Cretaceous sediments deposited upon it (Applin, 1951). It formed a relatively stable base for Eocene carbonate deposition (Williams et al., 1977). The arch did not affect mid-Ter tiary to Holocene sediment deposition (Williams et al., 1977; Scott, 1997). The Sanford High, named by Ve rnon (1951), is a positive feat ure located in Volusia and Seminole counties. It is a prominent structur e affecting the near surface depositional and postdepositional environments within the map area (F igure 4). Vernon (1951) de scribed this feature as “a closed fold that has been faulted, the Sanford high being located on the upthrown side”. The Ocala Limestone and Hawt horn Group are missing over th is feature and post-Hawthorn Group sediments (undifferentiated Pliocene/Pleisto cene shelly sediments) directly overlie the Avon Park Formation in the vicinity of the Sa nford High (see OF MS 105, Plate 2).

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FLORIDA GEOLOGICAL SURVEY 8 The St. Johns Platform, intr oduced by Riggs (1979a, 1979b), extends northward from the Sanford High into St. Johns County. This platfo rm, which is expressed on the erosional surface of the Ocala Limestone, dips gently north-north west towards Jacksonville (Scott, 1983). This is evident throughout the map area (OFMS 105; Plate 2) Undifferentiated sediments, thickest on the flanks of the Mt. Dora, DeLand and Crescent City ridges, have subsequently been deposited on the exposed undifferentiated Pliocene/Pleist ocene shelly sediment s, Miocene Hawthorn Group and Eocene carbonates. These consist of residual clays, sands, and aeolian sands deposited during the Miocene to Holocene (Scott, 1997). Figure 4. Principal subsurface structures of north Florida (modif ied from Scott, 1988).

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OPEN-FILE REPORT 101 9 Geomorphology Healy (1975) recognized six po ssible marine terraces within the study area (Figure 5) based upon elevations above mean sea level (M SL): the Silver Bluff terrace at elevations between 1 and 10 feet (0.3 and 3 meters), the Pamlico terrace at elevati ons between 10 and 25 feet (3 and 7.6 meters), the Ta lbot terrace at elevations betw een 25 and 42 feet (7.6 and 12.8 meters), the Penholloway terrace at elevations between 42 and 70 feet (12.8 and 21.3 meters), the Wicomico terrace at elevations between 70 to 100 feet (21.3 to 30.5 meters) and the Sunderland/Okefenokee terrace at elevations be tween 100 and 170 feet ( 30.5 and 51.8 meters). Detailed discussions and correlations of these marine terraces and relict shorelines have been attempted by many authors, including Ma tson and Sanford (1913), Cooke (1931, 1939), Flint (1940, 1971), MacNeil (1950), Alt a nd Brooks (1965), Pirkle et al. (1970), Healy (1975), and Colquhoun et al. (1991). Figure 5. Terraces in the st udy area (after Healy, 1975). According to Scott et al., (in preparation) the study area falls within three geomorphic districts: the Barrier Island Se quence District, the Central Lake s District and the Ocala Karst District (OFMS 105; Plat e 3, Figure 2). These dist ricts are further subdivided into terranes (OFMS 105; Plate 3, Figure 3) by Scott et al., (in preparation).

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FLORIDA GEOLOGICAL SURVEY 10 Barrier Island Sequence District The Barrier Island Sequence District extends into Florida from Georgi a. The district is characteri zed by beach ridges, dunes an d paleo-lagoons. The distri ct extends from the FloridaGeorgia state line southward to the vicinity of Lake Okeechobee It lies to the east of the Okeefenokee Basin District, the Ocala Karst Distri ct, the Central Lakes Dist rict, and the Sarasota River District. It lies north of the Everglades Di strict (OFMS 105, Plate 3, Figure 2). Elevations within the District range from s ea level to more than 145 feet (44.2 meters) above MSL. The surficial and shallow subsurface sediments of the district were deposited during the Plio-Pleistocene and lie unconformably on sediments ranging from the Middle Eocene Avon Pa rk Formation to the Oligocene-Miocene Hawthorn Group. Beach ridge plains o ccur in several areas of the Barrier Island Sequence District at elevations ranging from near sea level to more than 75 feet (22.9 meters) above MSL. In the study area, these occur on the At lantic Coastal Complex and portions of the Lower St. Johns River Valley. Drainage patterns in thes e areas may be strongly co ntrolled by the relict beach ridges forming, in some cases, a distinct trellis dr ainage pattern. The b each ridge swales are of ten swampy and control the development of lakes on po rtions of the Osceola Plain. The Barrier Island Sequence District contains relict (or paleo) lagoons. The occurrence of the lagoonal features is most prominent in the southern portion of the district in the headwaters of the St. Johns River. White (197 0) thought that this area was no t a paleo-lagoon but a beach ridge plain that had been reduced in stature by dissoluti on of incorporated shell material. He stated that there were relict beach ri dges in the area and that the ridges controlled the drainage. Modern topographic maps, however, do not show the beach ridges nor do they reve al a drainage pattern indicative of beach ridges. This paleo-lagoon lies between the Atlantic coast on the east and a prominent erosional scarp on the west. The scarp toe occurs at approximately 30 feet (9.1 meters) above MSL and extends nearly continuously from the southern-most portion of the Barrier Is land Sequence District northward to the Florida-Georgia state line. The paleo-lagoon extends uninterrupted from the southern end of the district to southern Volusia County. Nort hward from southern Volusia County the relict lagoon is either interru pted or partially covered by beach ridges. However, the lagoon can be recognized as far nort h as the vicinity of Jack sonville in Duval County. Atlantic Coastal Complex The Atlantic Coastal Complex extends from the Florida-Georgi a line to northern Brevard County (OFMS 105, Plate 3, Figure 3) In the study area, the terrane consists of Pliocene through recent barrier beach ridges and dunes that are consis tent with the terrane as a whole. Elevations range from sea level to 90 feet (27.4 meters) above MSL. With in the mapped area, elevations range from sea level to approximately 50 feet (1 5.2 meters) above MSL. There are multiple coast parallel creeks and swamps in th e swales separated by ridges and broad scale development of trellis drainage. Some of the major water features include the Tomoka River, Spruce Creek, Graham Swamp and the Halifax River. The latter tw o, made more distinct by construction of the Intracoastal Waterway, separate the modern barrier island from th e mainland to the west. In the study area, the terrane has varying thickness of undifferentiated Quaternary, undifferentiated Tertiary and Quaternary shelly sediments and outcrops of the Pleistocene Anastasia Formation near the Atlantic co ast (OFMS 105, plate 2).

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OPEN-FILE REPORT 101 11 Lower St. Johns River Valley The Lower St. Johns River Valley has b een hypothesized by Scott (2013, personal communication) as part of a paleo-lagoon. The relict lagoon featur e extends nearly continuously from the headwaters of the St. Johns River in Pa lm Beach County to central Duval County. In Volusia County, the paleo-lagoon is either partia lly interrupted or partially covered by beach ridges. In this area, the Atlantic Coastal Co mplex separates the Uppe r St. Johns River Valley from the Lower St. Johns River Va lley (OFMS 105, Plate 3, Figure 3). The southern end of this interruption corresponds to the west ward turn of the St. Johns River as it occupies the St. Johns River Offset. The southern end of the Lower St. Johns River Valley includes Crescent Lake and extends northward to central Duval County wher e the St. Johns River turns east toward the Atlantic Ocean and some beach ridge uplands separate the St. Johns River Valley from the drainages associated with the Nassau and St. Mary s Rivers. Elevations of the terrane range from sea level to more than 80 (24.4 meters) above MS L. Within the study area, elevations range from sea level to 45 feet (13.7 meters) above MSL. Variable thicknesses of undifferentiated Quaternary sediments lie on undi fferentiated Pliocen e/Pleistocene shelly sediments or the Hawthorn Group in the terrane. Central Lakes District The Central Lakes District oc cupies most of the Central Highlands of Cooke (1939) in peninsular Florida. The district extends from eastern Alachua County, southeastern Bradford County and southern Clay County to southernmost High lands County. The Central Lake District lies east and south of th e Ocala Karst District, sout h of the Okefenokee Distri ct, west of the Barrier Island Sequence District and north of the Sarasota River District and the Everglades District (OFMS 105; Plate 3, Figure 2). A thick (up to 200 feet [6 1 meters]) sequence of siliciclastic and carbonate sediments of the Hawthorn Grou p, siliciclastic sediments of the Cypresshead Formation and undifferentiated s iliciclastic sediments overlie the Ocala Limestone in the district. Dissolution of the limestone and subsequent subs idence or collapse has created th e characteristic rolling hills, sinkhole lakes and dry sinks that dominate the landscape. Much of the terrane is internally drained due to the karst features and the permeable sand co ver. District-wide eleva tions range from near sea level to over 300 feet (91.4 mete rs) above MSL. Within the mapped area, elevations vary from near sea level in the St. Johns River Offset to more than 200 feet (61 meters) above MSL on the Mt. Dora Ridge. In the stud y area, the Central Lakes District includes the Crescent City Ridge, the DeLand Ridge, the Fort McCoy Pl ain, the Mt. Dora Ridg e, the Ocklawaha Rive r Valley and the St. Johns River Offset. These ridge features were once part of a more extens ive Cypresshead Formation upland that subsequently was erosiona lly altered leaving the remnant highs. Crescent City Ridge The Crescent City Ri dge lies in northwestern Volusia County and southeastern Putnam County (OFMS 105, Plate 3, Fi gure 3). It is located between the St. Johns River Offset and the Lower St. Johns River Valle y. Crescent Lake lies at the easter n toe of the ridge. The lake likely represents a portion of the pale o-course of the ancestral St. Johns River, abandoned when the river began to occupy the offset. Elevations vary from approximately 25 f eet (7.6 meters) to 125 feet (38.1 meters) above MSL. Local ly, relief on the ridge approaches 50 feet (15.2 meters). The

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FLORIDA GEOLOGICAL SURVEY 12 terrain is a rolling, karstic landscape with closed-b asin lakes. A thin sequence of Quaternary sand overlies the Cypresshead Formati on and undifferentiated Pliocene/Pl eistocene shelly sediments. The Hawthorn Group is absent under th e ridge within the mapped area. DeLand Ridge The DeLand Ridge occurs in western Vo lusia County extending north-south from near the Flagler County boundary to the Seminole County line (OFMS 105, Plate 3, Figure 3). Elevations on the DeLand Ridge vary from approxima tely 20 feet (6.1 meters) to more than 100 feet (30.5 meters) above MSL within the mapped area and statewide. Loca lly, relief on the ridge approaches 50 feet (15.2 meters). The terrain is a rolling karstic landscape with closed basin lakes. A paleo-sand dune field occurs in the south-cen tral portion of the ridge The DeLand Ridge lies on top of the Sanford High. In portions of Volusia County, the Hawthorn Group and the Ocala Limestone are absent due to erosion and Cypresshead Form ation and undifferentiated Pliocene/Pleistocene shelly se diments lie on the Middle Eocen e Avon Park Formation. Thin remnants of the Ocala Limestone are presen t under limited portions of the DeLand Ridge. Fort McCoy Plain The Fort McCoy Plain is a rela tively flat, poorly to moderately drained area just east of the Ocala Karst Hills and southeast of the Hawt horne Lakes Region (OFMS 105; Plate 3, Figure 3). Scattered sinkholes are present within the terra ne and elevations range from approximately 40 feet (12.2 meters) to approximate ly 90 feet (27.4 meters) above MSL within the study area. The Fort McCoy Plain is underlain by sediments of the Hawthorn Group, which are mantled with variable thicknesses of undifferen tiated Quaternary sediments (Sco tt et al., 2001; Green et al., 2009a; Green et al., 2009b). Mt. Dora Ridge The Mt. Dora Ridge occurs in the western portion of the st udy area in Marion, Putnam and Lake counties. The terrain is a rolling karstic landscape with numerous lakes. Elevations on the Mt. Dora Ridge statewide and within the mappe d area vary from 10 feet (3 meters) to more than 200 feet (61 meters) above MSL. Relie f often exceeds 100 feet (30.5 meters). Karst processes acting through a thick se quence of siliciclastic sediment s (deep-cover karst) created the landscape. Dissolution of the Ocala Limestone and carbonates within the Hawthorn Group is responsible for the development of the Mt. Dora Ridge’s distinctive la ndscape. A paleo-sand dune field occurs in the eastern portion of the ri dge in eastern Marion and northern Lake counties (OFMS 105, Plate 1). The area, known as the Big Scrub in th e Ocala National Forest, is highly karstified. Tertiary/Quaternary dune sediments (TQd) overlie the Cypresshead Formation on part of the Mt. Dora Ridge. Elsewhere, the Cypr esshead Formation lies on the Hawthorn Group. Ocklawaha River Valley The Ocklawaha River Valley is a narrow valley extending from near the Lake-Marion County line northward to the Marion-Putnam Count y line. To the south, the valley abuts the Tavares Lakes Region. To the nort h, it merges with the St. Johns River Offset. The headwaters of the Ocklawaha River occur in Lake Griffin, in the Tavares Lakes Region, a broader and more karstic portion of the Central La kes Region. As it enters the Oc klawaha River Valley, the river becomes confined to a narrow valley bounded by th e Ocala Karst Hills and the Fort McCoy Plain

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OPEN-FILE REPORT 101 13 on the west and the Mt. Dora Ridge on the east (OFMS 105; Plate 3, Figure 3). The terrane is underlain by Cypressh ead Formation, Hawthorn Group sediments and undifferentiated Quaternary sediments. Elevations of the valley within the stud y area range from 40 feet (12.2 meters) to 70 feet (21.3 meters) above MSL. St. Johns River Offset The St. Johns River flows northward from the headwaters in Palm Beach County, flowing into the Atlan tic Ocean in Duval County (OFMS 105; Plate 3, Figure 3). The upper and lower St. Johns River valleys follo w a pathway that is closer to the Atlantic coastline than the middle reach of the river between Sanford and Palatka. At the a pproximate latitude of Sanford, Seminole County, the river jogs westward th en northward in a narrow valley bounded in the study area by the Mt. Dora Ridge on the west and the DeLand Ridge and the Crescent City Ridge on the east. White (1970) named and described this as the St. Johns River Offset. Elevations in the terrane vary from less than 5 feet (1.5 mete rs) to 75 feet (22.9 meters) above MSL. White believed that this portion of the St. Johns River’s course was firs t developed in the Pliocene or early Pleistocene by dissolution of the underl ying Eocene carbonate sedi ments. Pirkle (1971) suggested that the dissolution al ong the west-to-east trend resulte d from faulting and fracturing of the Eocene rocks. White (1970) believed that a complex geomorphic hist ory was necessary to force the St. Johns River out of its coast-paralle l course and into a mo re inland, older valley. Within the offset there are varying thicknesses of undifferentiated Quaterna ry sediments lying on the Ocala Limestone. Ocala Karst District The Ocala Karst District en compasses a broad area extend ing from Wakulla County in the panhandle to Hillsborough and Pine llas counties in west-central peninsular Florida (OFMS 105, Plate 3, Figure 2). Carbonate sediments ranging from the Middle Eo cene Avon Park Formation to the Oligocene-Miocene Ta mpa Member of the Arcad ia Formation (Hawthorn Group) lie near the land surface. Dissolution of thes e sediments has created distinct landforms that characterize the district, including caves, caverns numerous springs sinking (swallets) and resurgent streams. The Ocala Karst District merges with the Central Lakes District with which it sh ares a karstic influence (OFMS 105; Plate 3, Figure 2). The southern terminus of the distri ct occurs where the impermeable Hawthorn Group sediments retard the development of karst features in the Sarasota River District and streams and rivers become more common. Elevations within the district range from se a level to over 300 fe et (91.4 meters) above MSL. Only a small portion of the District occurs along the southwest corner of the mapped area (OFMS 105; Plate 3, Fi gure 3). Elevations range from 40 feet (12.2 meters) to 180 feet (54.9 meters) above MSL in the southeas tern portion of the Ocala Karst Hills within the mapped area. The topography over much of th e district is gently rolling with only minor relief. Sinclair and Stewart (1985) de lineated zones of similar karst development in Florida based on the thickness and type of sedi ment cover and on the sinkhole type s. Carbonate sediments of the Ocala Karst District are overlain by siliciclastics of varying thickness rangi ng from a few feet (one meter) to as much as 200 feet (61 meters) ove r carbonate sediments. C over subsidence and cover collapse sinkholes are the dominant sinkhole type in the district. Rock collapse sinks occur but are uncommon.

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FLORIDA GEOLOGICAL SURVEY 14 Regional geomorphic terranes are recognized within the Ocala Karst District based on elevation, abundance of karst features, drainage, and relief. One geomorph ic terrane, the Ocala Karst Hills, is recognized within the Ocala Karst Di strict within the mapped area based on elevation, abundance of karst features, drainage, and relief (OFMS 105, Plate 3, Figures 1 and 3). Ocala Karst Hills The Ocala Karst Hills terrane occurs from north-central Marion County southward to northeastern Sumter Coun ty (OFMS 105, Plate 3, Figure 3). Stat ewide, elevations in the terrane area range from 20 feet (6.1 meters) to 195 feet (59.4 meters) above MSL. Elevations of the terrane within the mapped area range from 40 feet (12. 2 meters) to 180 feet (5 4.9 meters) above MSL. Several springs are present in the Ocala Karst Hills, including Silver Springs, which occurs along the eastern edge of the terrane along the boundary with the Central Lakes District. Hawthorn Group sediments are thin to absent in the terr ane. Cypresshead Formation sediments overlie Hawthorn Group in the area (Green, et al., 2009a). There is a sma ll area in the Ocala Karst Hills along the southwestern boundary of the mapped area which ha s undifferentiated Quaternary sediments at the surface (OFMS 105, Plate 1). LITHOSTRATIGRAPHIC UNITS Tertiary System Eocene Series Avon Park Formation The Middle Eocene Avon Park Formation (Tap), first described by Applin and Applin (1944), is entirely a subsurface unit within the USGS Daytona Beach 30 x 60 minute quadrangle. It was encountered in many of th e wells utilized for this study a nd efforts were made to include it in the geologic cross sections where suitable well coverage existed (see OFMS 105, Plate 2). Lithology of the Avon Park Formation can vary between limestone and dolostone. The limestones consist of cream to light brown to tan, poorlyto well-indurated, variably fossiliferous grainstone and w ackestone, with rare mudst one. The limestones are often interbedded with tan to brown, very poorlyto well-indurated, very fine to medium crystalline, fossiliferous (molds and casts), vuggy dolostones. Minor clay beds and organic-rich laminations may occur, especially at or near the top of the unit. Accessory minerals include chert, pyrite, celestine, gypsum and quartz (some as doubly-terminat ed euhedral crystals “floating” in vugs). Fossils present in the unit in clude molluscs, foraminifera ( Spirolina sp., Lituonella floridana Bolivina spp., Cushmania [ Dictyoconus ] americana ), Cribrobulimina cushmani and Fabiana cubensis echinoids ( Neolaganum [ Peronella ] dalli), algae and carbonized plant remains. Porosity in the Avon Park Formation is generally intergranular in the limestone section. Fracture porosity occurs in th e more densely recrystallized dolostone and intercrystalline porosity is characteristic of sucr osic textures. Pinpoint vugs a nd fossil molds are present to a lesser extent. Distinction between the Middle Eocene A von Park Formation and the unconformably overlying unit, the Upper Eocene Ocala Limestone, can at times be difficu lt in the study area, particularly in the vicinity of the Sanford High (where the O cala Limestone is often thin to

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OPEN-FILE REPORT 101 15 missing). Dolomitization of the Avon Park Fo rmation and common recrystallization of the lowermost Ocala Limestone has significantly altered the original rock lithology and fabric. Fossil indicators are only somewhat helpful because the latest deposits of the Avon Park Formation and the earliest deposits of the Ocala Limestone are both bank assemblages, consistent with deposition in a shallow-water limestone bank or plateau, not unlike the present day Bahama Banks (Bryan, 2004). The top of the Avon Park ranges from approxi mately 5 feet (1.5 meters) below MSL in W-5611 (OFMS 105; Plate 2, cross-section D-D') to approximate ly 170 feet (51.8 meters) below MSL in W-18815 (OFMS 105; Plate 2, cross-sections E-E'). Due to graphical space constraints, as well as limited coverage of deeper wells, the total thickness of the Avon Park Formation was not investigated in this study. The Avon Park Formation forms part of the FAS (Southeastern Geological Society Ad Hoc Co mmittee on Florida Hydrostra tigraphic Unit Definition, 1986). Ocala Limestone The Upper Eocene Ocala Limestone (To), first described by Dall and Harris (1892), is a biogenic marine limestone comprised largely of foraminifera, molluscs, echinoids and bryozoans. The Ocala Limestone, which sits unconformably on the Avon Park Formation throughout most of the st udy area, is thin to absent in the vicinity of the Sanford High. Based on lithologic differences, the Ocala Lime stone can be informally subdivided into an upper and lower unit (Scott, 1991). This subdivision, while often apparent in cores and quarries, is not readily apparent in cuttings. As a conseque nce of this, the geologic crosssections do not break out the upper and lower Ocala Limestone. The upper unit is typically a white to cream, fineto coarse -grained, poorly to well-indurated, moderately to well-sorted, very fossiliferous limestone (wackest one, packstone, and grainstone). Fossils commonly include foraminifera, bryozoans, molluscs and a rich diversity of echinoi ds. The lower unit is typically a white to cream, fineto medi um-grained, poorly to moderately indurated, moderatelyto wellsorted limestone (grainstone to pack stone). Fossils include foraminifera ( Lepidocyclina ocalana Amphistegina pinarensis Nummulites [ Camerina ] vanderstoki Nummulites [ Operculinoides ] ocalana ), bryozoans, algae, molluscs, echinoids, and crustaceans. The Ocala Limestone occurs th roughout most of th e study area (except where missing on the Sanford High) and is near the surface along the northwestern portion of the map area (OFMS 105, Plate 2). The top of the Ocala Limestone ranges from 23 f eet (7 meters) above MSL in W10360, (OFMS 105; Plate 2, cross-section B-B') to 97 feet (29.6 meters) below MSL in W-4065 and W15133 (OFMS 105; Plate 2, cross-section A-A'). A pproximately 60 percent of the wells utilized for geologic cross-sec tions penetrate the entire thickne ss of the Ocala Limestone. In these wells, the thickness of the Ocala Limest one ranges from 135 feet (41 meters) in W-11634 (OFMS 105; Plate 2, cross-section B-B') to 5 feet (1.5 meters) in W-15352 (OFMS 105; Plate 2, cross-section D-D'). The Ocala Limestone is generally thicke st in the western portion of the study area away from the Sanf ord High. The Ocala Limestone forms part of the FAS (Southeastern Geological Soci ety Ad Hoc Committee on Florid a Hydrostratigraphic Unit Definition, 1986).

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FLORIDA GEOLOGICAL SURVEY 16 Miocene Series Hawthorn Group Sediments of the Miocene Ha wthorn Group are thought to have been deposited over the Peninsular Arch throughout much of the study area, but erosion and karstification have removed these sediments from the cres t of the Ocala Plat form (Cooke, 1945; Espenshade and Spencer, 1963; Scott, 1983). The unit is also missing in the vicinity of the Sanford High (Scott, 1988). Hawthorn Group sediments within the study area consist of phosphatic siliciclastics (sands, silts and clays) and carbonates (dolosto ne with minor limestone). Fo ssils in the Hawthorn Group are sparse but may include vertebrate s, corals, and molluscs. Benthi c foraminifera characteristic of the Hawthorn Group include Archaias spp. and Sorites sp. Williams et al. (1977) report that the most commonly found fossils are oysters and coral heads. Within the mapped area, the Hawthorn Gr oup is composed of the Penney Farms Formation (Thpf), the Marks H ead Formation (Thmh) and the Coosawhatchie Formation (Thc; OFMS 105; Plate 2, Figure 2) While these formations can be id entified and delineated in cores, they are often not readily differe ntiated in cuttings, particularly where cavings fr om above cause mixing of the sediments during drilling. In th ese instances, they are referred to as undifferentiated Hawthorn Group (Th) on the cross-sections. In instances where they can reliably be differentiated, the formations are shown on the cro ss-sections (OFMS 105; Plate 2, cross-sections B-B' and C-C'). Unit descri ptions for the Hawthorn Group listed below are summaries and the reader is referred to Sc ott (1988) for a more co mplete discussion of lithologies, variability and rela tionships of these lithological ly complex formations. Hawthorn Group sediments are unconformably overlain by Tertiary/Quaternary dune sediments, Cypresshead Formation (TQc) and undiffer entiated Quaternary sediments (Qu). In the mapped area, Ha wthorn Group sediments occur primari ly west of Lake George and the St. Johns River (OFMS 105, Plate 1). The top of the Ha wthorn Group ranges between 70 feet (21.3 meters) above MSL in W-3886 (OFMS 105; Plat e 2, cross-section BB') to 56 feet (17 meters) below MSL in W-19453 (OFMS 105; Plate 2, cross-section C-C'). The Hawthorn Group sediments range in thic kness from 78 feet (23.8 meters) in we ll W-19451 to 10 feet (3 meters) in well W-10360 (OFMS 105; Plate 2, cross-section B-B'). Sedi ments of the Ha wthorn Group form the Intermediate aquifer system/Intermediate c onfining unit (IAS/ICU; S outheastern Geological Society Ad Hoc Committee on Florida Hy drostratigraphic Unit Definition, 1986). Penney Farms Formation The Penney Farms Formation (Thpf) consists of variable admixtures of dolostone, quartz sand, phosphatic sand and clay. The sand content is variable and at times the unit becomes a dolomitic sand. Phosphatic sand is common and may be present in amounts exceeding 25 percent with an average of 5 to 10 percent (Scott, 1988). Clay percentages are ge nerally minor (less than 5 percent) and often increase towards the top of the unit in the dolostones. The dolostones are medium-gray to pale-yellowish brown and are ge nerally moderate lyto well-indurated. Mollusc molds are common in the dolostones. Intraclas ts are common in the hard, finer-grained dolostones in the lower portion of the unit. These intraclasts are co mposed of dolomite similar to the rest of the unit, but they often have rims of phosphate replacement along the edges of the clasts (see OFMS 105; Plate 2, Fi gure 2, Photo 2). Limestone, whic h occurs sporadically in the lower portion of the unit, is generally dolom itic, phosphatic, and quartz sandy. The Penney

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OPEN-FILE REPORT 101 17 Farms Formation unconformably overlies the O cala Limestone within the mapped area. Where present in the mapped area, it is overlain unconformably by the Marks Head Formation (Hawthorn Group). The base of the Marks Head Formation is placed at the contact between the darker-colored sands and clays of the upper Pe nney Farms and the generally lighter-colored interbedded sands, clays, and dolostone of th e Marks Head Formation (OFMS 105; Plate 2, cross-sections B-B' and C-C'). Marks Head Formation The Marks Head Formation (Thmh) consists of interbedded sands, clays and dolostones. Limestone, while uncommon, does occur within th e unit (Scott, 1988). Do lostones are generally quartz sandy, phosphatic and clayey. Colors of th e dolostones range from ye llowish-gray to olive gray. Induration, which varies i nversely with the clay content, ranges from poorlyconsolidated to well indurated. Phosphate content typically range s up to five percent but may occasionally be significantly higher. Quartz sand content ranges from five percent to greater than 50 percent. The unit is overlain unconformably by the Coosawha tchie Formation (Hawt horn Group), although this unconformity is often no t readily apparent. In genera l, the contact between the Coosawhatchie and Marks Head form ations is placed at the top of the first hard ca rbonate bed or light-colored clay unit below the darker-colore d, clayey, dolomitic quartz sands and dolostones of the basal Coosawhatchi e Formation (Scott, 1988). Coosawhatchie Formation The Miocene Coosawhatchie Fo rmation (Thc) consists of quartz sands, dolostones and clays. The unit ranges in color from greenish-gr ay and light gray to olive gray. The most common lithology in the upper section of the unit is characteristically a sandy to very sandy dolostone which may be interbedded with quartz sands and clays (Scott, 1988). Quartz sands and clays dominate and dolostones become subordinate in the lower portion of the section. The quartz sands are fineto medium -grained, generally phosphatic, cl ayey and dolomit ic. In many instances, the sands grade into dolostones and clay s. Clay content is variable and may range from five to more than 30 percent (Scott, 1988). Phos phate content is highly variable, ranging from a trace to more than 20 percent. Coarse phosphate sands and pebbles are present but not common in the unit. The unit is unconformably overla in by the Pliocene/Pleistocene Cypresshead Formation (TQc) in the vicinity of the Mt. Dora Ridge (OFMS 105, Plate 2, cross-sections B-B' and C-C'). Hawthorn Group (Undifferentiated) In the areas between the Sanford High and the Peninsular Arch, sediments of the Coosawhatchie, Marks Head and Penney Farms formations often b ecome difficult to break out lithologically. In these areas, sediments of th e Hawthorn Group are mapp ed as Hawthorn Group, undifferentiated (Th; Scott, 1988). Where exposed west of the mapped area, the undifferentiat ed Hawthorn Group is light olive gray and blue gray in unweathered sec tions and reddish-brown to reddish-gray in weathered sections (Green et al., 2009a). It c onsists of poorlyto moderately-consolidated,

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FLORIDA GEOLOGICAL SURVEY 18 clayey sands to silty clays and relatively pure clays with little-to-no pho sphate due to leaching and transport (Scott, 2001). It is typically deeply weathered. Where present, the undifferentiated Hawt horn Group unconformably overlies the Ocala Limestone (Scott et al., 2001). It is unconformabl y overlain by the Cypres shead Formation (TQc) and undifferentiated Quaternary and Ho locene sediments (O FMS 105, Plate 2). Due to the karstic nature of the Mt. Dora Ridge, elevations of the Hawthorn Group are highly variable. Within the study area, the top of the unit may exceed 70 feet (21.3 meters) above MSL as in well W-3886 (OFM S 105; Plate 2, cross-s ection B-B') or be at a depth of more than 55 feet (16.8 meters) below MS L (OFMS 105; Plate 2, cross-s ection C-C', W-19453). Along the flanks of the ridge, thin beds of the undifferentia ted Hawthorn Group were penetrated in various wells (OFMS 105, Plate 2). In th ese, the top of the undifferen tiated Hawthorn Group ranges from 33 feet (10 meters) above MSL in W-10360 (OFMS 105; Plate 2, cross-section B-B') to 34 feet (10.4 meters) below MSL well W-8415 (OFMS 105; Pl ate 2, cross-section A-A’). Thickness of the undifferentiated Hawthorn Group varies between 10 to 45 feet (3 to 13.7 meters). Undifferentiated Hawthorn Group sediments are of ten clayey sands and onl y rarely consist of relatively pure clays. The Ha wthorn Group generally has low perm eability and forms part of the IAS/ICU (Southeastern Geologi cal Society Ad Hoc Committee on Florida Hydrostratigraphic Unit Definition, 1986). Tertiary/Quaternary Systems Pliocene/Pleistocene Series Cypresshead Formation The Pliocene/Pleistocene Cypresshead Formatio n (TQc), named by Huddlestun (1988), is a mottled reddish-brown to reddish-orange to white unconsolidated to poorly consolidated, fineto very coarse-grained, variably clayey to clean quartz sand. Crossbedded sands are common within this formation. Discoid quartzite pebbles mica, and ghosts of nearshore marine molluscs are often present. The Cypressh ead Formation is present throughout much of the study area and forms the core of the various ridges present in the region (see geomorphology section for more discussion). East of the St. Johns River, it typically beco mes a more weathered, finer-grained, well-sorted sand and silt. In core s, the unit is often characterized by beds of fine grained, well sorted sand with thin layers of clay dispersed through the sand. Elevations range from near sea level to over 180 feet (54.9 meters) above MSL in the mapped area. The Cypresshead Formation thickne ss ranges between 90 feet to 35 feet (27.4 to 10.7 meters) in study area wells. These sediments sit unconformably on th e undifferentiated Ha wthorn Group (Th) or Coosawhatchie Formation (Hawthorn Group; Thc) west of the St. Johns River and undifferentiated Pliocene/Pleisto cene shelly sediments (TQsu) in the eastern portion of the mapped area (OFMS 105; Plate 2). Permeable se diments of the Cypresshead Formation form part of the surficial aquifer system (SAS; Southeastern Geol ogical Society Ad Hoc Committee on Florida Hydrostratigra phic Unit Definition, 1986).

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OPEN-FILE REPORT 101 19 Pliocene/Pleistocene Shelly Sediments A sequence of undifferentiated P liocene/Pleistocene shelly sedi ments lies east of the St. Johns River and occupies the section where the Hawthorn Group is mis sing around the Sanford High. Huddlestun (1988) named this unit the Nashua Formation. Much of the evidence listed by Huddlestun (1988) was based on biostratigraphic correlation and not lithologic distinction. Efforts were made by the authors to locate the ty pe section of the Nashua Formation, as defined by Huddlestun (1988), to no avail. Since we did not have adequate core control and could not locate the type section, these authors have decided to utilize the convention of the Scott, et al. (2001) and map these sediments as undifferentia ted Pliocene/Pleistocene shelly sediments (TQsu). The unit sits unconformably on the Ocala Limestone or, in the vi cinity of the Sanford High, the Avon Park Formation (OFMS 105; Plate 2, cross-sections A-A', B-B' and D-D'). Huddlestun (1988) indicated that the unit grades laterally into the Cypresshead Formation (TQc) in the vicinity of the Trail Ridge (northwest of the mapped area). Evidence from this study, however, indicates that the unit is at least in part, older than the Cypresshead Formation. This may be a result of prograding of deltaic Cypr esshead Formation sediments over TQsu marine sediments during changes in sea level. Work currently underway at the Florida Museum of Natural History indicates that some of these shelly sands just nor th of the study area are Pliocene (Roger Portell, personal communica tion). These undifferentiated sh elly sands are overlain by the Cypresshead Formation in the Crescent City and DeLand ridges (O FMS 105, Plate 2, crosssection D-D'). Elsewhere, the unit is unconfor mably overlain by undifferentiated Quaternary sediments, Quaternary beach ri dge and dune sediments (Qbd) or the Anastasia Formation (Qa). Undifferentiated Pliocene/Pleist ocene shelly sediments (TQsu) typically consist of fineto-medium quartz sand with variable amounts of calcilutite, shell and clay. Shells may vary from whole to fragments and may occasionally beco me the dominant lithology. Other accessory minerals may include calcite, ara gonite, clay, mica, heavy minerals and minor phosphate. Colors range from light gray to light olive gray. The top of the undifferentiated Plio cene/Pleistocene shelly sediments ranges from 50 feet (15.2 meters) above MSL in W-561 1, (OFMS 105; Plate 2, cross-section D-D') to 45 feet (13.7 meters) below MSL in W-15667 (OFM S 105; Plate 2, crosssection E-E'). The thickness of the undifferentiated Pliocene/Pleistocen e shelly sediments in the cro ss-section wells varies from 95 feet (28.9 meters) in W-15133 (OFMS 105; Plate 2, cross-s ection A-A') to 15 feet (4.6 meters) in W-18282 (OFMS 105; Plate 2, cross-section A-A'). Permeable se diments of the undifferentiated Pliocene/Pleistocene shelly sedime nts form part of the SAS (Sout heastern Geological Society Ad Hoc Committee on Florida Hydrostr atigraphic Unit Definition, 1986). Tertiary/Quaternary Dunes Tertiary/Quaternary dunes (TQd), while not a formally recognized lithostratigraphic unit, are mapped following the convention of Scott et al. (2001) in order to facilitate a better understanding of Florida’s geol ogy. Where LiDAR is availa ble these dunes are readily differentiated from other units by their distin ct topographic expression. These dune sediments are fine-to-medium quartz sand with varying amount s of disseminated orga nic matter. They are generally found at elevations above 100 feet (3 0.5 meters) MSL, although there are areas along the flanks of the Mt. Dora Ri dge where elevations of these dune sands can be lower. Sands forming these dunes are thought to be deri ved from re-working of sediments from the

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FLORIDA GEOLOGICAL SURVEY 20 Cypresshead Formation (TQc) and undifferentiated Quaternary se diments (Qu). There are large portions of the Mt. Dora Ridge in the Ocala National Forest a nd sections of the DeLand Ridge which have Tertiary/Quaternary dune sediment s mapped (OFMS 105, Plate 1). These sediments are considered part of the SAS (Southeastern Geological Society Ad Hoc Committee on Florida Hydrostratigraphic Un it Definition, 1986). Pleistocene to Holocene Series Anastasia Formation The Anastasia Formation (Qa) is present with in the Atlantic Coastal Complex in a narrow band along the eastern edge of the study area. The formation, named by Sellards (1912), is composed of interbedded coquinoid limestone a nd quartz sands. It typically occurs as an orangish-brown, unindurated to moderately indurated coquina consisting of whole and broken mollusc shells in a quartz sand matrix. The co quina is commonly cemente d by sparry calcite. The sands occur as light gray to tan and or angish-brown, unconsolid ated to moderately indurated, unfossilif erous to very fossiliferous beds The unit sits unconformably on undifferentiated Pliocene/Pleistocen e shelly sediments (TQsu; OF MS 105, Plate 2, cross-section E-E'). The top of the Anastasi a Formation ranges from 5 feet (1.5 meters) above MSL in wells W-3473 and W-11047 (OFMS 105; Plat e 2, cross-section E-E'), to 12 feet (3.7 meters) below MSL in W-3976 (OFMS 105; Plate 2, cross-section A-A'). The thickness of the Anastasia Formation in the cross-section wells varies fro m 45 feet (13.7 meters) in W-15667 to 10 feet (3 meters) in W-18815 (OFMS 105; Plate 2, cross-section E-E'). This formation is considered part of the SAS (Southeastern Geol ogical Society Ad Hoc Committee on Florida Hydrostratigraphic Unit Definition, 1986). Undifferentiated Quaternary Sediments Undifferentiated Quaternary sediments (Qu) in the study area lie unconformably on the Hawthorn Group, undiffer entiated Pliocene/Pleistocene sh elly sediments or Cypresshead Formation (OFMS 105, Plate 2, cross-sections). The undifferentiated Quaternary sediments present in the mapped area may be highly variable in thickness. Generally, these undifferentiated Quaternary sedi ments consist of white to gray to orange to blue-green, fineto coarse-grained, clean to clayey unf ossiliferous sands, sandy clays and clays with variable admixtures of organics. Th e undifferentiated Quaternary sediments form part of the SAS (Southeastern Geol ogical Society Ad Hoc Committee on Florida Hydrostratigraphic Unit Definition, 1986). Quaternary Beach Ridge and Dune Quaternary beach ridge and dune sedi ments (Qbd) are a subdivision of the undifferentiated Quaternary sediment s that are noted on the basis of surficial expression of relict beach ridges and dunes. While not a formally recognized lithostratigraphic unit, it is mapped following the convention of Sco tt et al., (2001) in order to f acilitate a better understanding of Florida’s geology. This unit unconformably overlies undifferen tiated Pliocene/Pleistocene shelly

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OPEN-FILE REPORT 101 21 sediments (TQsu), or the Anastasi a Formation (Qa) in the eastern part of the study area (OFMS 105; Plates 1 and 2). Beach ridge and dune sediments are dominantly siliciclastic sands and are unconsolidated to poorly consolidated. Organics typically occur as disseminated organic matrix, roots and plant debris, carbonized remains or charcoal. The unit is considered part of the SAS (Southeastern Geological Society Ad Hoc Co mmittee on Florida Hydrostra tigraphic Unit Definition, 1986). Holocene Sediments Sediments mapped as Holocene (Qh) may in clude quartz sands, marls, organics, and minor carbonate sands and mud. They may also in clude fresh-water mollus cs. Within the study area, they occur as floodplain depos its in the vicinity of Lake George, the St. Johns River and the Ocklawaha River. These sediment s are considered part of th e SAS (Southeastern Geological Society Ad Hoc Committee on Florida Hy drostratigraphic Unit Definition, 1986). HYDROGEOLOGY Hydrostratigraphic units within the map area, in ascending orde r, consist of the Floridan aquifer system (FAS), the Inte rmediate aquifer system/Interme diate confining unit (IAS/ICU), and the Surficial aquifer system (SAS; South eastern Geological Societ y Ad Hoc Committee on Florida Hydrostratigraphic Un it Definition, 1986). The FAS, the primary source for springs and drinking water in the region, is generally co mprised of carbonate units of the Avon Park Formation and the Ocala Limest one. The sands, silts, clays and carbonates of the Hawthorn Group comprise the IAS/ICU. Th e IAS/ICU is highly localized and laterally discontinuous in the study area. Th e SAS is comprised of the Cypre sshead Formation, undifferentiated Pliocene/Pleistocene shelly se diments (TQsu), Tertiary/Quate rnary dune sediments (TQd), undifferentiated Quaternary sediments (Qu), beach ridge and dune sediments (Qbd), and Holocene sediments (Qh). Where clayey siliciclastic sediments of the Hawthorn Group and younger units are thick and continuous, they provide confinement for the FAS, but where the clayey siliciclastic sediments of the Hawthorn Group and younger units are thin, missing or lack significant clay component, karst features often occur. Severa l of these are found in the Crescent City and DeLand ridges. GEOPHYSICAL LOGGING As part of this project, th e St. Johns River Water Mana gement District (SJRWMD) conducted geophysical logging on new wells drilled in the study area by the Florida Geological Survey. Boreholes were logged with a variety of geophysical tools, including Gamma (natural gamma log), Caliper, and Inducti on logs (Fluid Resistivity and Fluid Conductivity). The geophysical log of particular in terest in this study was the gamma log for its usefulness in differentiating the various lithostratigraphic units by r ecording the naturally occurring gamma-ray activity in the lithology of the borehole wall. By comparing gamma-ray activit y between lithostratigraphic units it is often possible to differentiate them. This log is particularly useful for diff erentiating between Hawthorn Group units and subjacent and superjacent formations. Kwader (1982) and Scott (1988) discuss the

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FLORIDA GEOLOGICAL SURVEY 22 gamma-ray response from clay miner als and phosphate typical to th e formations in the Hawthorn Group. Development of high gamma activity occurs when minerals incorporate high percentages of potassium, uranium or thorium in their lattice structures. Potassium-rich sources include potassium feldspar, mica, and illitic cl ay. Uranium and thoriu m tend to be found in phosphorite, apatite, organic material and dolomite. Gamma-ray intensity units were measured in counts pe r second (CPS). In Figure 6, gamma-ray intensity units are shown on the log horizontal axis in CPS for W-19451 (see OFMS 105, Plate 2, cross-section B-B'). Carbonates of the Ocala Limestone and Avon Park Formation have the lowest intensity gamma peaks in contrast to the high intensity radioactiv ity of the Hawthorn Group. Formations above the Hawthorn Group, such as the Cypresshead Formation and Tertiary-Quaternary dune sediments (TQd), typically have much lower intensity signatures. In the study area, elevated radioactivity primarily results from the inclusion of phosphate grains. Medium intensity gamma-ray signatures are fro m moderately radioactive clay-minerals and from organic material or pe at (Davis et. al., 2001). Stratigraphy and Gamma-Ray Log Interpretation Avon Park Formation Logs from the Avon Park Formation typically show a combination of low gamma-ray intensity dolostone with distinct beds of relatively higher gamma-ray intensity lignite or organic layers. The top of the Avon Park Formation characteris tically ranges from a yellow-gray dolomitic wackestone to a yellow-brown recrystallized dolostone. Below this initial lith ology, but usually at or near the top of the unit, there can be variable amounts of black to dark brown, finely particulate to fibrous, partially decomposed organic material or lignite. Figure 6. Gamma Log of W-19451 (see OFMS 105 p late 2 B-B' )

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OPEN-FILE REPORT 101 23 The organic matter can occur as finely disseminated particles, sand to pebble sized blebs, identifiable leaf or sea-grass fo ssils, laminations or as discrete beds. One such bed of organicrich material can be seen in Figure 6, the top of the Avon Park Formation at approximately 295 feet (89.9 meters) belo w land surface (BLS). Ocala Limestone In contrast to the higher intensity gamma-r ay signature of the Hawthorn Group, the Ocala Limestone is easily identified on the gamma-ray log. This unit characteristically produces the lowest gamma-ray intensity in the Eocene stra tigraphic sequence and can be used as a low baseline for relative gamma-ray in tensity (Davis et. al., 2001). In general, the Ocala Limestone has lower gamma-ray intensity than the underlying Avon Park Formation. In the study area, however, do lomitization of the Avon Park Formation and recrystallization of the lowermos t Ocala Limestone has significantl y altered the original rock lithology and fabric making th e distinction of the gamma-ray signatures between these units more difficult. The presence of organics when at or near the top of Avon Park Formation (e.g., Figure 6) can assist in determin ing the contact between these tw o formations. One such organicrich zone occurs at 295 feet (89.9 meters) BLS. Hawthorn Group The Hawthorn Group consists of a complex se quence of siliciclastics and carbonates with varying percentages of phosphate minerals. The resulting gamma-ray peaks are, in general, significantly higher than those of the forma tions above and below the Hawthorn Group which makes this unit easily discernible on geophysical l ogs (Figure 6). The Hawthorn Group in the west ern portion of the study ar ea consists of the Penney Farms, Marks Head and Coosawhatchie formations The gamma-ray logs from the cores drilled for this study show a pa ttern of three generalized zones co rresponding with these formations. However, the pattern shows a variation in the in tensities and thickness of peak groups dependent on the lithologic variation of the sample. Fo r example, in W-19451 (O FMS 105; Plate 2, crosssection C-C') the higher gamma-ray intensity zones at approximately 138-158 feet (42-48.2 meters) BLS correlate with th e Coosawhatchie Formation. The C oosawhatchie Formation in this well consists primarily of silicicl astics with varying amounts of do lomitic clay and fine to pebble sized phosphate ranging in content between three a nd fifteen percent. The second zone is a low intensity gamma-ray zone of the Marks Head Formation (between 158-167 feet [48.2-50.9 meters] BLS) consisting of a well-indurated, light gray recrystallized dolo silt with one to three percent fine-to-medium phosphate. The third z one correlates with the Penney Farms Formation showing a drop in the gamma-ray intensity at approximately 167 feet ( 50.9 meters) BLS at an unconformity, followed by a significant peak at about 168 feet (51.2 me ters) BLS where the lithology is a phosphatic, clayey sand with burrows and intraclasts. The Penney Farms Formation in this core is highly variable in lithology and phosphate content as reflected in the gamma-ray log. The Penney Farms Formation unconformably overlies the Ocala Limestone. At this contact, the gamma-ray l og intensity drops significantly and the delineation of these two forma tions is readily apparent (Figure 6).

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FLORIDA GEOLOGICAL SURVEY 24 Pliocene/Pleistocene shelly sediments In the study area east of the St. Johns River, undifferentiated Pliocene/Pleistocene shelly sediments (TQsu) lie unconformably over the Hawthorn Group, and below the undifferentiated Quaternary sediments or Cypresshead Form ation (OFMS 105, Plate 2). Undifferentiated Pliocene/Pleistocene shelly sediments present in the mapped area may be highly variable in thickness and typically consist of fine to medium quartz sand with variable amounts of calcilutite, shell, phosphate and clay. Other accessory minerals may include calcite, aragonite, clay, mica, and heavy minerals. The presence of phosphate and heavy minerals can cause spikes in the gamma-ray log making this unit readily distinguishable from the overlying Cypresshead Formation or undifferentiated Quaternary sediments. Cypresshead Formation and Tertia ry/Quaternary dune sediments The Cypresshead Formation (TQc) is typically composed of variably clayey quartz sand, silt and gravel characteristic of a fluvio-deltaic deposit. The sediments of the Tertiary/Quaternary dune sediment s (TQd) are fine to medium quartz sand with varying amounts of disseminated organic matt er. Often, the Cypresshead Formation cannot be readily distinguished from the overlying TQd by the gamma-ray log due to their similar lithologies. Because these units lack phosphate, they ar e easily distinguishable from the underlying Hawthorn Group (Figure 6). DERIVATIVE PRODUCTS Several derivative products will come from this project. During the mapping project, data from over 400 wells with samples were anal yzed. Formation picks, made on all available wells with cores and cuttings samples, allow crea tion of a structure contou r map of the top of the FAS, along with the construction of structure contour and isopach maps of the IAS/ICU in the area. Additional derivative data anticipated to come from this mapping effort include aquifer vulnerability assessment maps. Data derived from prior STATEMAP produc ts have often been used to augment other Florida Geological Survey and Florida a quifer vulnerability assessment (FAVA) projects in the state (Art hur et al., 2007; Ba ker et al., 2007).

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OPEN-FILE REPORT 101 25 REFERENCES Alt, D., and Brooks, H.K., 1965, Age of the Florida marine terraces: Journal of Geology, v. 73, p. 406-411. Applin, P., 1951, Possible future pe troleum provinces of North Am erica Florida: American Association of Petroleum Geol ogists Bulletin, v. 35, p. 405-407. Applin, P.L., and Applin, E.R., 1944, Regional subs urface stratigraphy and structure of Florida and southern Georgia: Amer ican Association of Petrol eum Geologists Bulletin, v. 28, p. 1673-1753. Arthur, J.D., Wood, H.A.R., Ba ker, A.E., Cichon, J.R., and Raines, G.L., 2007, Development and implementation of a Bayesian-based aquifer vulnerability assessment in Florida: Natural Resources Research, v. 16, p. 93-107. Baker, A.E., Wood, H.A.R., a nd Cichon, J.R., 2007, The Marion County Aquifer Vulnerability Assessment: unpublished report submitted to Marion County Board of County Commissioners in fulfillmen t of Marion County Project No. SS06-01, March 2007, 42 p. Bryan, J.R., 2004, Larger foraminifera: In troduction, biology, eco logy, taxonomic and stratigraphic listings and comments on Florid a fossil assemblages: Gainesville, Florida Paleontological Society, Florida Fossil Invertebrates, Part 6, 28 p. Colquhoun, D.J., Johnson, G.H., Peebles, P.C., H uddlestun, P.F., and Scot t, T., 1991, Quaternary geology of the Atlantic Coastal Plain, in Morrison, R.B., ed., Quat ernary nonglacial geology; Conterminous U.S.: Boulder, Geological Society of Amer ica, The Geology of North America, v. K-2, p. 629-650. Cooke, C.W., 1931, Seven coastal terraces in the southeastern United States: Washington Academy of Sciences Journal, v. 21, p. 503-513. ___________, 1939, Scenery of Florida interpreted by a geologist: Florida Geological Survey Bulletin 17, 120 p. ___________, 1945, Geology of Fl orida: Florida Geological Survey Bulletin 29, 342 p. Copeland, R., 2003, Florida spring cl assification system and spring glossary: Florida Geological Survey Special Publication 52, 17 p. Copeland, R., Doran, N.A., White A.J., and Upchurch, S.B., 2009, Regional and statewide trends in Florida’s spring and well groundw ater quality (1991-2003) : Florida Geological Survey Bulletin 69, 203 p. Dall, W.H., and Harris, G.D., 1892, Correlation pa pers, Neocene: U.S. Geological Survey Bulletin 84, 349 p.

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FLORIDA GEOLOGICAL SURVEY 26 Davis, J., Johnson R.A., Boniol D. and Rupert, F ., 2001, Guidebook to the correlation of geophysical well logs within the St. Johns River Water Management District: Florida Geological Survey Special Publication 50, 114 p. Espenshade, G.H., and Spencer, C.W., 1963, Geologic features of phosphate deposits of northern peninsular Florida: United States Geological Survey Bulletin 1118, 115 p. Flint, R.F., 1940, Pleistocene features of the Atlantic coastal plain: Ameri can Journal of Science, v. 238, p. 757-787. _______, 1971, Glacial and Quaternary Geology: New York, John Wiley and Sons, Inc., 892 p. Green, R.C., Williams, C.P., Paul, D.T., Kromhout C., and Scott, T.M., 2009a, Geologic map of the eastern portion of the USGS Ocala 30 x 60 minute quadrangle, nor th-central Florida: Florida Geological Survey Open-File Map Series 100, scale 1:100,000, 3 plates. Green, R.C., Williams, C.P., Pa ul, D.T., Kromhout, C., and Scott, T.M., 2009b, Text to accompany geologic map of th e eastern portion of the US GS Ocala 30 x 60 minute quadrangle, central Florida: Florida Geological Survey Open-File Report 93, 28 p. Green, R.C., Williams, C.P., Flor A.D., Paul, D.T., Kromhout, C., and Scott, T.M., 2010a, Geologic map of the western por tion of the USGS Ocala 30 x 60 minute quadrangle, northcentral Florida: Florida Ge ological Survey Open-File Ma p Series 101, scale 1:100,000, 3 plates. Green, R.C., Williams, C.P., Flor, A.D., Paul, D.T., Kromhout, C., and Scott, T.M., 2010b, Text to accompany geologic map of the western portion of the USGS Ocala 30 x 60 minute quadrangle, central Florida: Florida Geological Survey Open-File Report 94, 29 p. Healy, H.G., 1975, Terraces and shorelines of Flor ida: Florida Geological Survey Map Series 71, scale: 1:2,095,200. Huddlestun, P.F., 1988, A revisi on of the lithostratigraphic units of the Coastal Plain of Georgia, the Miocene through Holocene: Georgi a Geologic Survey Bulletin 104, 262 p. Jones, G.W., Upchurch, S.B., and Champion, K. M., 1996, Origin of ni trate in groundwater discharging from Rainbow Springs Marion County, Florida: Br ooksville, Southwest Florida Water Management District Report, 155 p. Kwader T., 1982, Interpretation of bo rehole geophysical logs in sha llow carbonate environments and their application to ground water resour ces investigations [Ph.D. Thesis]: Florida State University, Tallahassee, 322 p. MacNeil, F.S., 1950, Pleistocene s horelines in Florida and Georgi a: U.S. Geological Survey Professional Paper 221-F, p. 95-107.

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OPEN-FILE REPORT 101 27 Matson, G.C., and Sanford, S., 1913, Geology and groundwater of Florida: U.S. Geological Survey Water Supply Paper 319, 445 p. Miller, J.A., 1986, Hydrogeologic framework of the Floridan aquifer system in Florida and in parts of Georgia, Alabama, and South Caroli na: Regional Aquifer-System Analysis: U.S. Geological Survey Professiona l Paper 1403-B, 91 p., 33 plates. Phelps, G.G., 1994, Hydrogeology, water quality and potential for contamination of the upper Floridan Aquifer in the Silver Springs GroundWater Basin, central Marion County, Florida: U.S. Geological Survey Water-Resour ces Investigations Report 92-4159, 69 p. _______, 2004, Chemistry of groundwater in the Silv er Springs Basin, with an emphasis on nitrate: U.S. Geol ogical Survey Scientific Inve stigations Report 2004-5144, 54 p. Pirkle, E.C., Jr., Yoho, W.H., and Hendry, C.W., Jr., 1970, Ancient sea level stands in Florida: Florida Geological Survey Bulletin 52, 61 p. Pirkle, W.A. 1971, The offset course of the St Johns Rive r, Florida: Southeastern Geology, v. 13, No. 39, 59 p. Poucher, S., and Copeland, R., 2006, Speleological a nd karst glossary of Florida and the Caribbean: Gainesville, University Press of Florida, 196 p. Puri, H.S., and Vernon, R.O., 1964, Summary of th e geology of Florida and a guidebook to the classic exposures: Florida Geological Survey Special Publication 5, revised, 312 p. Riggs, S.R., 1979a, Petrolog y of the Tertiary phosphorite system of Florida: Economic Geology, V. 74, p. 195-220. _______, 1979b, Phosphorite sedimentation in Fl orida – a model phosphogenic system: Economic Geology, v. 74, p. 285-314. Schmidt, W., 1984, Neogene stratig raphy and geologic hi story of the Apalac hicola Embayment: Florida Geological Survey Bulletin 58, 146 p. Scott, T.M., 1983, The Hawthorn Form ation of Northeastern Florida – Part I: The geology of the Hawthorn Formation of North eastern Florida: Florida Ge ological Survey Report of Investigation 94, 90 p. _________, 1988, The lithostratigraphy of the Hawthorn Group (Miocene) of Florida: Florida Geological Survey Bulletin 59, 148 p. _________, 1991, A geological overview, in Scott, T.M., Lloyd, J. M., and Maddox, G.L., eds., Florida’s ground-water quality mo nitoring program, hydrogeol ogic framework: Florida Geological Survey Special Publication 32, 97 p.

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FLORIDA GEOLOGICAL SURVEY 28 _________, 1992a, Geologic map of Putnam County, Fl orida: Florida Geol ogical Survey OpenFile Map Series 6, scale 1:126,720. _________, 1992b, Geologic map of Flagler County, Flor ida: Florida Geological Survey OpenFile Map Series 7, scale 1:126,720. _________, 1992c, Geologic map of Volusia County, Fl orida: Florida Geological Survey OpenFile Map Series 8, scale 1:126,720. _________, 1992d, Geologic map of Lake C ounty, Florida: Florida Ge ological Survey Open-File Map Series 9, scale 1:126,720. _________, 1992e, Geologic map of Marion County, Flor ida: Florida Geological Survey OpenFile Map Series 13, scale 1:126,720. _________, 1997, Miocene to Holocene history of Florida, in Randazzo, A.F. and Jones, D.S., eds., The geology of Florida: Gainesville, University Press of Florida, p. 57-67. _________, 2001, Text to accompany the geologic map of Florida: Florida Geological Survey Open-File Report 80, 29 p. Scott, T.M., Campbell, K.M., Rupert, F.R., Art hur, J.A., Green, R.C., Means, G.H., Missimer, T.M., Lloyd, J.M., and Duncan, J.G., 2001, Geol ogic map of Florida: Florida Geological Survey Map Series 146, scale 1:750,000. Scott, T.M., Means, G.H., Means, R.C., and Meegan R.P., 2002, First magnitude springs of Florida: Florida Ge ological Survey Open -File Report 85, 138 p. Scott, T.M., Means, G.H., Meega n, R.P., Means, R.C., Upchurch, S.B., Copeland, R.E., Jones, J., Roberts, T., and Willet, A., 2004, Springs of Flor ida: Florida Geological Survey Bulletin 66, 377 p. Scott, T.M., Paul, D.T., Means, G.H., and Willia ms, C.P. (in preparation), Geomorphic map of Florida: Florida Geol ogical Survey, scale 1:750,000. Sellards, E.H., 1912, The soils and other surface resi dual materials of Florid a: Florida Geological Survey Fourth Annual Report, p. 1-79. Sinclair, W.C., and Stewart, J. W., 1985, Sinkhole type, development, and distribution in Florida: Florida Geological Survey Map Seri es 110, scale 30 miles to 1 inch. Southeastern Geological Soci ety Ad Hoc Committee on Florid a Hydrostratigraphic Unit Definition, 1986, Hydrogeological un its of Florida: Florida Geological Survey Special Publication 28, 8 p.

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OPEN-FILE REPORT 101 29 Upchurch, S.B., Champion, K.M., Schnieder, J.C ., Hornsby, D., Ceryak, R., and Zwanka, W., 2004, Defining springshed boundaries and waterquality domains near first-magnitude springs in north Florida [abstract]: Florida Scientist, v. 67, Supplement 1, p. 52 U.S. Geological Survey, 1979, 1:100,000-scale metric topographi c map of Daytona Beach, Florida: Reston, U.S. Ge ological Survey, 1 sheet. Vernon, R.O., 1951, Geology of Citrus and Levy Coun ties, Florida: Florid a Geological Survey Bulletin 33, 256 p. Waltham, T., Bell, F., and Culshaw, M., 2005, Sinkholes and subsidence, karst and cavernous rocks in engineering and construction: Chichester, Praxis Publishing Ltd., 382 p. White, W.A., 1970, The geomorphology of the Flor ida peninsula: Florida Geological Survey Bulletin 51, 164 p. Williams, K.E. Dodd, K., and Randa zzo, A.F., 1977, The ge ology of the wester n part of Alachua County, Florida: Florida Geological Survey Report of Investigations 85, 98 p. ACKNOWLEDGEMENTS The authors extend many thanks to the pe rsonnel that assisted with access to land holdings: Donna Watkins with the Florida Depart ment of Environmental Protection’s Division of Recreation and Parks expedited the permit process for rock sample collection in Florida State Parks. Steven R. Miller with the St. Johns River Water Management’s Bureau of Land Management was instrumental in granting the Sp ecial Use Authorization that allowed the FGS access for field reconnaissance and drilling on SJ RWMD properties. SJRWMD Land Managers Crystal Morris, Stuart Jones, and R.H. Davi s provided us the necessary information and resources for accessing their properties. Tim Te lfer and Michael Lagass e, from Flagler County Land Management helped with access and a guide d tour of the Haw Creek Conservation Area. Robert Macon, Tonnee Davis and District Ranger Mike Herrin helped obtain a Special Use Permit required for dr illing and sample collecting in the Ocala National Forest. We would also bestow a special thanks to Jeffery B. Davis with the SJRWMD Bureau of Groundwater Sciences for shar ing his knowledge and experien ce on the overall geology and geophysical data within the st udy area as well as s ponsoring the 2012 SMAC meeting in Palatka Florida. Jill Andrea, with the SJRWMD Divi sion of Water Resources GeoSpatial Scientist, provided the FGS STATEMAP progr am with valuable GIS data. LiDAR coverage provided by Richard Helfst from Lake C ounty GIS Services Division of Information Technology was extremely valuable in developing our geology ma ps and our top of rock modeling. Discussions with Roger Portell the Director of Invertebrate Paleontology at the Florida Museum of Natural History, were helpful in establishing the age co rrelation of some of the Tertiary/Quaternary units within the study area. The FG S STATEMAP staff w ould like to thank Mr. Johnny Arrigano, owner of Arrow Materials and Excavating, fo r allowing us to sample his borrow pit. Seth Bassett, Bob Cleveland, Levi Hannon, Le e Hartman, Jesse Hur d, David Paul, Eric Thomas and Christopher Williams provided field support for drilling opera tions. Tyler Weinand of the St. Johns River Water Management Dist rict provided geophysi cal logging for the new

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FLORIDA GEOLOGICAL SURVEY 30 cores collected in the study ar ea. Levi Hannon, Alan Baker and James Cichon worked to make sure all wells were appropriately located using every piece of archived well location information that could be found. Thank you to Frank Rupert, Jackie Lloyd, and Harley Means who reviewed, discussed and edited the product. Tom Scott continues to be an asset to geolog ic mapping in Florida and the ongoing work to revise the st ate’s geomorphic map. Th is geologic map was funded in part by the Office of the Florida Geological Survey of the Florida Department of Environmental Protection and by the United St ates Geological Survey National Cooperative Geologic Mapping Program under assi stance award number G12AC2041 2 in Federal fiscal year 2012.

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OPEN-FILE REPORT 101 31 APPENDIX A: FGS WELLS UTILIZED FOR STUDY This table lists FGS wells within the boundari es of the USGS Daytona Beach 30 x 60 minute quadrangle utilized for the top of rock mode l and/or geologic mapp ing. Due to graphical constraints, not all wells will appear on Plate 1 of OFMS 105. The first 40 wells in the table were utilized for geologic crosssections and appear on Plat es 1 and 2 of OFMS 105. Map ID Well Label Data Source Sample T yp e Latitude Longitude 24K Quad Elevation (ft) Total De p th (ft) 1 W-657 FGS Cuttings 29.057207 81.284507 DELAND 72 511 2 W-1118 FGS Cuttings 29.037454 81.166793 DAYTONA BEACH SW 40 5958 3 W-3473 FGS Cuttings 29.348867 -81.088452 ORMOND BEACH 10 147 4 W-3886 FGS Cuttings 29.061175 -81.633026 FARLES LAKE 112 114 5 W-3957 FGS Cuttings 29.328611 -81.771944 LAKE KERR 74 131 6 W-3976 FGS Cuttings 29.279701 -81.062553 ORMOND BEACH 8 207 7 W-4065 FGS Cuttings 29.33066 -81.329785 CODYS CORNER 13 188 8 W-4069 FGS Cuttings 29.442638 -81.538192 CRESCENT CITY 65 115 9 W-5039 FGS Cuttings 29.320232 -81.392224 SEVILLE 13 107 10 W-5573 FGS Cuttings 29.012656 -81.645593 FARLES LAKE 57 200 11 W-5611 FGS Cuttings 29.121674 -81.315836 DELAND 80 225 12 W-6136 FGS Cuttings 29.050833 -81.755278 LAKE MARY 144 240 13 W-6137 FGS Cuttings 29.2666 -81.030356 ORMOND BEACH 12 160 14 W-7842 FGS Cuttings 29.298333 -81.835277 LAKE KERR 90 280 15 W-8134 FGS Cuttings 29.035346 -81.289603 DELAND 86 390 16 W-8415 FGS Cuttings 29.322472 -81.966477 FORT MCCOY 66 145 17 W-10360 FGS Cuttings 29.025462 -81.962674 LAKE WEIR 98 520 18 W-10935 FGS Cuttings 29.036371 -81.465068 LAKE WOODRUFF 42 310 19 W-11047 FGS Cuttings 29.243591 -81.046165 DAYTONA BEACH 5 210 20 W-11634 FGS Cuttings 29.053629 -81.880195 LAKE WEIR 89 295 21 W-12371 FGS Cuttings 29.05537 -81.018042 SAMSULA 25 250 22 W-13594 FGS Cuttings 29.146102 -81.031728 DAYTONA BEACH 31 200 23 W-14318 FGS Core 29.384685 -81.512155 CRESCENT CITY 54 158 24 W-14752 FGS Core 29.211111 -81.728888 JUNIPER SPRINGS 68 93 25 W-15118 FGS Cuttings 29.274364 -81.09203 ORMOND BEACH 23 200 26 W-15133 FGS Cuttings 29.287264 -81.159063 FAVORETTA 23 205 27 W-15352 FGS Cuttings 29.136797 -81.334614 LAKE DIAS 64 240 28 W-15667 FGS Cuttings 29.433963 -81.114219 FLAGLER BEACH EAST 0 120 29 W-15729 FGS Cuttings 29.061527 -81.348229 DELAND 72 450 30 W-15921 FGS Cuttings 29.310377 -81.494339 SEVILLE 39 170 31 W-17567 FGS Cuttings 29.471388 -81.809999 LAKE DELANCY 81 200 32 W-17571 FGS Cuttings 29.142777 -81.704999 JUNIPER SPRINGS 118 71 33 W-18282 FGS Cuttings 29.321666 -81.539444 WELAKA SE 20 170 34 W-18815 FGS Core 29.200555 -81.039444 DAYTONA BEACH 6 1001 35 W-19022 FGS Cuttings 29.325832 -81.079722 ORMOND BEACH 6 86 36 W-19444 FGS Core 29.0335 -81.09509 SAMSULA 43 200 37 W-19448 FGS Core 29.227563 -81.362112 LAKE DIAS 28 200 38 W-19451 FGS Core 29.049766 -81.675616 FARLES LAKE 178 303 39 W-19452 FGS Core 29.406833 -81.806416 LAKE DELANCY 123 318 40 W-19453 FGS Core 29.254066 -81.7698 LAKE KERR 114 273 41 W-153 FGS Cuttings 29.030308 -81.911444 LAKE WEIR 58 350 42 W-177 FGS Cuttings 29.485565 -82.016519 CITRA 69 95 43 W-181 FGS Cuttings 29.375246 -81.899592 EUREKA DAM 21 65 44 W-183 FGS Cuttings 29.23577 -81.964577 LYNNE 69 133 45 W-194 FGS Cuttings 29.485162 -81.186782 FLAGLER BEACH WEST 20 70 46 W-195 FGS Cuttings 29.459726 -81.262505 BUNNELL 14 65 47 W-196 FGS Cuttings 29.435251 -81.31732 BUNNELL 5 65 48 W-197 FGS Cuttings 29.409561 -81.367767 BUNNELL 11 120

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FLORIDA GEOLOGICAL SURVEY 32 Map ID Well Label Data Source Sample T yp e Latitude Longitude 24K Quad Elevation (ft) Total De p th (ft) 49 W-198 FGS Cuttings 29.353407 -81.510599 WELAKA SE 45 100 50 W-199 FGS Cuttings 29.270276 -81.645293 SALT SPRINGS 38 80 51 W-200 FGS Cuttings 29.313234 -81.771858 LAKE KERR 50 120 52 W-201 FGS Cuttings 29.182203 -81.890483 LYNNE 62 100 53 W-202 FGS Cuttings 29.156872 -81.955242 LYNNE 64 75 54 W-245 FGS Cuttings 29.029765 -81.293389 DELAND 57 264 55 W-939 FGS Cuttings 29.035512 -81.326351 DELAND 84 290 56 W-1129 FGS Cuttings 29.492157 -81.913262 EUREKA DAM 18 55 57 W-1131 FGS Cuttings 29.448032 -81.91754 EUREKA DAM 76 56.7 58 W-1132 FGS Cuttings 29.432991 -81.934441 EUREKA DAM 18 69 59 W-1133 FGS Cuttings 29.432991 -81.934441 EUREKA DAM 18 55.4 60 W-1134 FGS Cuttings 29.416018 -81.921456 EUREKA DAM 19 68 61 W-1135 FGS Cuttings 29.404321 -81.917402 EUREKA DAM 19 75 62 W-1136 FGS Cuttings 29.375268 -81.900744 EUREKA DAM 33 85 63 W-1137 FGS Cuttings 29.375268 -81.900744 EUREKA DAM 33 97 64 W-1139 FGS Cuttings 29.317171 -81.899779 FORT MCCOY 25 78 65 W-1140 FGS Cuttings 29.302207 -81.916158 FORT MCCOY 30 54.8 66 W-1141 FGS Cuttings 29.28741 -81.932539 FORT MCCOY 29 62.3 67 W-1142 FGS Cuttings 29.274113 -81.955438 FORT MCCOY 45 77.5 68 W-1143 FGS Cuttings 29.259654 -81.955344 FORT MCCOY 30 82.5 69 W-1144 FGS Cuttings 29.244925 -81.978438 LYNNE 33 96 70 W-1147 FGS Cuttings 29.182281 -82.016943 OCALA EAST 56 100 71 W-1148 FGS Cuttings 29.182281 -82.016943 OCALA EAST 56 69 72 W-1149 FGS Cuttings 29.182281 -82.016943 OCALA EAST 56 70 73 W-1150 FGS Cuttings 29.185918 -82.012733 OCALA EAST 57 92 74 W-1151 FGS Cuttings 29.182281 -82.016943 OCALA EAST 56 81 75 W-1152 FGS Cuttings 29.171454 -82.029134 OCALA EAST 39 112 76 W-1153 FGS Cuttings 29.162065 -82.039221 OCALA EAST 67 91.9 77 W-1491 FGS Cuttings 29.470614 -81.302613 BUNNELL 14 117 78 W-1520 FGS Cuttings 29.363512 -81.342814 CODYS CORNER 9 130 79 W-1707 FGS Cuttings 28.982555 -82.041749 OXFORD 86 165 80 W-1712 FGS Cuttings 28.987422 -82.018405 OXFORD 76 111 81 W-1717 FGS Cuttings 29.230913 -81.265922 LAKE DIAS 33 150 82 W-1746 FGS Cuttings 29.230913 -81.265922 LAKE DIAS 33 5418 83 W-1762 FGS Cuttings 28.987222 -82.018611 OXFORD 76 141 84 W-1966 FGS Cuttings 29.069711 -81.976674 LAKE WEIR 108 141 85 W-2216 FGS Cuttings 29.184444 -81.881666 LYNNE 65 125 86 W-2444 FGS Cuttings 29.474951 -81.248174 FLAGLER BEACH WEST 19 80 87 W-2944 FGS Cuttings 29.210536 -81.043388 DAYTONA BEACH 9 282 88 W-2951 FGS Cuttings 29.211925 -81.043945 DAYTONA BEACH 9 167 89 W-3059 FGS Cuttings 29.492539 -81.151525 FLAGLER BEACH WEST 10 7077 90 W-3060 FGS Cuttings 29.492658 -81.155062 FLAGLER BEACH WEST 10 70 91 W-3183 FGS Cuttings 29.000774 -81.300398 DELAND 32 400 92 W-3291 FGS Cuttings 29.054688 -81.929566 LAKE WEIR 59 210 93 W-3292 FGS Cuttings 29.040086 -81.929522 LAKE WEIR 51 160 94 W-3472 FGS Cuttings 29.349634 -81.087677 ORMOND BEACH 11 147 95 W-3476 FGS Cuttings 29.162756 -81.100615 DAYTONA BEACH 24 496 96 W-3477 FGS Cuttings 29.191839 -81.07104 DAYTONA BEACH 27 505 97 W-3479 FGS Cuttings 29.48909 -81.147133 FLAGLER BEACH WEST 13 81 98 W-3527 FGS Cuttings 29.102162 -81.213429 DAYTONA BEACH SW 40 351 99 W-3528 FGS Cuttings 29.15803 -8 1.098204 DAYTONA BEACH 29 235 100 W-3532 FGS Cuttings 29.158755 -81.107694 DAYTONA BEACH 27 235 101 W-3534 FGS Cuttings 29.158596 -81.103186 DAYTONA BEACH 28 234 102 W-3535 FGS Cuttings 29.162735 -81.096405 DAYTONA BEACH 25 211 103 W-3540 FGS Cuttings 29.180526 -81.079953 DAYTONA BEACH 28 498

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OPEN-FILE REPORT 101 33 Map ID Well Label Data Source Sample T yp e Latitude Longitude 24K Quad Elevation (ft) Total De p th (ft) 104 W-3569 FGS Cuttings 29.199703 -81.040054 DAYTONA BEACH 6 200 105 W-3573 FGS Cuttings 29.199703 -81.040054 DAYTONA BEACH 6 160 106 W-3574 FGS Cuttings 29.199981 -81.033668 DAYTONA BEACH 7 160 107 W-3651 FGS Cuttings 29.433462 -81.149946 FLAGLER BEACH WEST 10 114 108 W-3653 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 182 109 W-3697 FGS Cuttings 29.064752 -81.300456 DELAND 82 138 110 W-3888 FGS Cuttings 29.106998 -81.619507 ALEXANDER SPRINGS 52 35 111 W-3889 FGS Cuttings 29.180555 -81.890277 LYNNE 61 171 112 W-3975 FGS Cuttings 29.474993 -81.672301 WELAKA 20 483 113 W-4057 FGS Cuttings 29.308011 -81.316391 CODYS CORNER 23 146 114 W-4059 FGS Cuttings 29.492423 -81.673809 WELAKA 21 80 115 W-4062 FGS Cuttings 29.496287 -81.589353 CRESCENT CITY 64 176 116 W-4067 FGS Cuttings 29.333713 -81.342141 CODYS CORNER 13 180 117 W-4223 FGS Cuttings 29.192808 -81.066501 DAYTONA BEACH 27 205 118 W-4226 FGS Cuttings 29.173609 -80.983332 PORT ORANGE 14 170 119 W-4227 FGS Cuttings 29.225639 -81.006629 DAYTONA BEACH 17 185 120 W-4228 FGS Cuttings 29.194704 -81.059776 DAYTONA BEACH 31 225 121 W-4580 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93 122 W-4581 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93 123 W-4582 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93 124 W-4583 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93 125 W-4584 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 90 126 W-4591 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93 127 W-4619 FGS Cuttings 29.270812 -81.068115 ORMOND BEACH 5 198 128 W-4622 FGS Cuttings 29.290667 -81.090834 ORMOND BEACH 38 201 129 W-5021 FGS Cuttings 29.476337 -81.673419 WELAKA 21 87 130 W-5029 FGS Cuttings 29.47379 -81.182468 FLAGLER BEACH WEST 23 115 131 W-5037 FGS Cuttings 29.409352 -81.305411 BUNNELL 13 76 132 W-5038 FGS Cuttings 29.384937 -81.188446 FLAGLER BEACH WEST 28 103 133 W-5040 FGS Cuttings 29.353809 -81.252695 CODYS CORNER 18 171 134 W-5309 FGS Cuttings 29.20207 -8 1.050299 DAYTONA BEACH 30 275 135 W-5430 FGS Cuttings 29.016345 -81.637199 FARLES LAKE 46 147 136 W-5489 FGS Cuttings 29.184116 -81.006367 DAYTONA BEACH 5 148 137 W-5607 FGS Cuttings 29.035671 -81.282938 DELAND 85 110 138 W-5613 FGS Cuttings 29.021047 -81.290983 DELAND 41 190 139 W-5614 FGS Cuttings 29.041225 -81.283379 DELAND 75 315 140 W-5743 FGS Cuttings 29.248311 -81.455902 PIERSON 68 250 141 W-5745 FGS Cuttings 29.053055 -82.039166 BELLEVIEW 84 124 142 W-5746 FGS Cuttings 29.474653 -81.741353 WELAKA 12 200 143 W-5758 FGS Cuttings 29.246366 -81.456459 PIERSON 70 250 144 W-5784 FGS Cuttings 29.20207 -8 1.050299 DAYTONA BEACH 30 210 145 W-5789 FGS Cuttings 29.005555 -82.010277 BELLEVIEW 71 112 146 W-6016 FGS Cuttings 29.034722 -82.043333 BELLEVIEW 89 800 147 W-6110 FGS Cuttings 29.037668 -81.319483 DELAND 71 304 148 W-6273 FGS Cuttings 29.138611 -81.849999 HALFMOON LAKE 54 141 149 W-6326 FGS Cuttings 29.01506 -81.372187 DELAND 18 101.5 150 W-6328 FGS Cuttings 29.190259 -81.075889 DAYTONA BEACH 28 210 151 W-6353 FGS Cuttings 29.0383 -81.302922 DELAND 65 220 152 W-7172 FGS Cuttings 29.011171 -81.346062 DELAND 49 95 153 W-7173 FGS Cuttings 29.011171 -81.346062 DELAND 49 198 154 W-7383 FGS Cuttings 29.226329 -82.049686 OCALA EAST 55 110 155 W-7697 FGS Cuttings 29.011111 -82.045555 BELLEVIEW 95 230 156 W-7781 FGS Cuttings 29.429444 -81.859194 LAKE DELANCY 139 328 157 W-7835 FGS Cuttings 29.040086 -81.929522 LAKE WEIR 51 180 158 W-7871 FGS Cuttings 29.172836 -81.084388 DAYTONA BEACH 22 200

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FLORIDA GEOLOGICAL SURVEY 34 Map ID Well Label Data Source Sample T yp e Latitude Longitude 24K Quad Elevation (ft) Total De p th (ft) 159 W-7917 FGS Cuttings 29.175255 -82.008141 OCALA EAST 54 180 160 W-8075 FGS Cuttings 28.987222 -82.043611 OXFORD 70 285 161 W-8108 FGS Cuttings 29.027097 -81.292974 DELAND 46 253 162 W-8132 FGS Cuttings 29.127777 -81.888611 LYNNE 108 105 163 W-8407 FGS Cuttings 29.201016 -81.929977 LYNNE 59 125 164 W-8411 FGS Cuttings 29.191922 -82.030363 OCALA EAST 39 192 165 W-8412 FGS Cuttings 29.266919 -81.916475 FORT MCCOY 73 165 166 W-8413 FGS Cuttings 29.322472 -81.966477 FORT MCCOY 66 173 167 W-8414 FGS Cuttings 29.141922 -81.977586 LYNNE 55 219 168 W-8453 FGS Cuttings 29.115539 -81.186447 DAYTONA BEACH SW 41 305 169 W-8455 FGS Cuttings 29.047492 -81.003929 SAMSULA 25 700 170 W-8458 FGS Cuttings 29.079998 -81.148306 DAYTONA BEACH SW 40 310 171 W-8503 FGS Cuttings 29.0522 -81.304741 DELAND 72 407 172 W-8562 FGS Cuttings 29.21535 -82.045555 OCALA EAST 38 105 173 W-8593 FGS Cuttings 29.145259 -81.145889 DAYTONA BEACH NW 43 100 174 W-8594 FGS Cuttings 29.026103 -81.187168 DAYTONA BEACH SW 38 91 175 W-10259 FGS Cuttings 29.325168 -81.114834 ORMOND BEACH 29 440 176 W-10304 FGS Cuttings 29.433462 -81.149946 FLAGLER BEACH WEST 10 88 177 W-10307 FGS Cuttings 29.505803 -81.884531 KEUKA 40 180 178 W-10332 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 228 179 W-10395 FGS Cuttings 29.214941 -82.012677 OCALA EAST 62 160 180 W-10430 FGS Cuttings 29.433462 -81.149946 FLAGLER BEACH WEST 10 66 181 W-10578 FGS Cuttings 29.069308 -82.012274 BELLEVIEW 99 158 182 W-10728 FGS Cuttings 28.996786 -81.716047 UMATILLA 51 130 183 W-10788 FGS Cuttings 29.274505 -81.832016 LAKE KERR 132 125 184 W-11046 FGS Cuttings 29.240535 -81.045608 DAYTONA BEACH 12 220 185 W-11099 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 300 186 W-11175 FGS Cuttings 29.060342 -81.264904 DELAND 70 550 187 W-11261 FGS Cuttings 29.422538 -81.733387 WELAKA 31 190 188 W-11301 FGS Cuttings 29.137546 -81.343747 LAKE DIAS 52 150 189 W-11329 FGS Cuttings 29.199448 -81.119452 DAYTONA BEACH 25 160 190 W-11394 FGS Cuttings 29.326639 -81.773417 LAKE KERR 87 140 191 W-11512 FGS Cuttings 29.21535 -82.045555 OCALA EAST 38 110 192 W-11520 FGS Cuttings 29.146102 -81.031728 DAYTONA BEACH 31 205 193 W-11569 FGS Cuttings 28.991614 -81.298574 ORANGE CITY 61 210 194 W-11648 FGS Cuttings 29.083072 -81.877976 LAKE WEIR 70 210 195 W-11694 FGS Cuttings 29.235221 -81.031039 DAYTONA BEACH 3 205 196 W-11696 FGS Cuttings 29.243867 -81.463401 PIERSON 75 200 197 W-11730 FGS Cuttings 29.171666 -81.837777 HALFMOON LAKE 65 160 198 W-11776 FGS Cuttings 29.336033 -81.131173 FAVORETTA 52 160 199 W-11828 FGS Cuttings 29.094752 -81.303576 DELAND 64 230 200 W-11848 FGS Cuttings 29.389014 -81.086141 FLAGLER BEACH EAST 15 155 201 W-11861 FGS Cuttings 29.406891 -81.158442 FLAGLER BEACH WEST 27 220 202 W-11929 FGS Cuttings 29.119536 -81.512696 ALEXANDER SPRINGS 3 114 203 W-11934 FGS Cuttings 29.164231 -81.534035 ASTOR 8 163 204 W-12014 FGS Cuttings 29.133777 -81.028007 DAYTONA BEACH 31 160 205 W-12021 FGS Core 29.233569 -81.17645 DAYTONA BEACH NW 27 71 206 W-12022 FGS Core 29.207202 -81.195617 DAYTONA BEACH NW 35 48 207 W-12023 FGS Core 29.163871 -81.21228 DAYTONA BEACH NW 39 57 208 W-12024 FGS Core 29.191925 -81.22895 DAYTONA BEACH NW 38 73 209 W-12025 FGS Core 29.218591 -81.219505 DAYTONA BEACH NW 33 71 210 W-12026 FGS Core 29.185258 -81.180335 DAYTONA BEACH NW 36 84 211 W-12027 FGS Core 29.020818 -81.204223 DAYTONA BEACH SW 39 74 212 W-12028 FGS Core 29.239147 -81.235336 DAYTONA BEACH NW 35 75 213 W-12029 FGS Core 29.141927 -81.238395 DAYTONA BEACH NW 41 57.5

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OPEN-FILE REPORT 101 35 Map ID Well Label Data Source Sample T yp e Latitude Longitude 24K Quad Elevation (ft) Total De p th (ft) 214 W-12031 FGS Core 29.09165 -81.160614 DAYTONA BEACH SW 41 92 215 W-12032 FGS Core 29.025817 -81.148117 DAYTONA BEACH SW 41 82 216 W-12034 FGS Core 29.225257 -81.252281 LAKE DIAS 37 92 217 W-12058 FGS Cuttings 29.377145 -81.131955 FLAGLER BEACH WEST 34 180 218 W-12059 FGS Cuttings 29.373439 -81.139285 FAVORETTA 21 260 219 W-12060 FGS Cuttings 29.38338 -81.131826 FLAGLER BEACH WEST 26 200 220 W-12061 FGS Cuttings 29.389809 -81.144256 FLAGLER BEACH WEST 23 120 221 W-12142 FGS Cuttings 29.007156 -81.342233 DELAND 56 230 222 W-12154 FGS Cuttings 29.090555 -81.068138 SAMSULA 21 100 223 W-12166 FGS Cuttings 29.26748 -81.077278 ORMOND BEACH 27 180 224 W-12228 FGS Cuttings 29.250531 -81.439074 SEVILLE 59 190 225 W-12340 FGS Cuttings 29.431675 -81.214119 FLAGLER BEACH WEST 23 325 226 W-12385 FGS Cuttings 29.136231 -81.145109 DAYTONA BEACH NW 43 150 227 W-12409 FGS Cuttings 29.201388 -81.913263 LYNNE 69 192 228 W-12632 FGS Cuttings 29.237521 -81.097118 DAYTONA BEACH 26 200 229 W-12633 FGS Cuttings 29.259533 -81.108549 ORMOND BEACH 20 200 230 W-12796 FGS Cuttings 29.19996 -81.061095 DAYTONA BEACH 29 150 231 W-12797 FGS Cuttings 29.146599 -81.153515 DAYTONA BEACH NW 42 140 232 W-12801 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 200 233 W-12808 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 220 234 W-12809 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 222 235 W-12810 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 210 236 W-12811 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 210 237 W-12904 FGS Cuttings 28.99751 -80.966672 EDGEWATER 29 210 238 W-12950 FGS Cuttings 29.083639 -81.067998 SAMSULA 22 120 239 W-13086 FGS Cuttings 29.360588 -81.966944 FORT MCCOY 73 103 240 W-13102 FGS Cuttings 29.491375 -81.951944 EUREKA DAM 64 160 241 W-13235 FGS Cuttings 29.065145 -81.250656 DELAND 50 120 242 W-13236 FGS Cuttings 29.263173 -81.110494 ORMOND BEACH 16 80 243 W-13414 FGS Cuttings 29.446626 -81.296821 BUNNELL 11 90 244 W-13415 FGS Cuttings 29.446626 -81.296821 BUNNELL 11 100 245 W-13416 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 200 246 W-13417 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 130 247 W-13426 FGS Cuttings 29.25944 -81.125108 FAVORETTA 8 100 248 W-13427 FGS Cuttings 29.162259 -81.01886 DAYTONA BEACH 9 80 249 W-13431 FGS Cuttings 29.431372 -81.230577 FLAGLER BEACH WEST 23 140 250 W-13440 FGS Cuttings 29.445797 -81.262863 BUNNELL 13 8856 251 W-13456 FGS Cuttings 29.145091 -81.145551 DAYTONA BEACH NW 44 270 252 W-13461 FGS Cuttings 29.145091 -81.145551 DAYTONA BEACH NW 44 270 253 W-13513 FGS Cuttings 29.431372 -81.230577 FLAGLER BEACH WEST 23 80 254 W-13546 FGS Cuttings 29.03224 -81.337657 DELAND 67 400 255 W-13595 FGS Cuttings 29.146102 -81.031728 DAYTONA BEACH 31 200 256 W-13596 FGS Cuttings 29.146102 -81.031728 DAYTONA BEACH 31 200 257 W-13678 FGS Cuttings 29.446626 -81.296821 BUNNELL 11 140 258 W-13689 FGS Cuttings 29.016896 -81.223145 DAYTONA BEACH SW 43 200 259 W-13695 FGS Cuttings 29.167776 -81.299602 LAKE DIAS 35 160 260 W-13837 FGS Cuttings 29.197252 -81.599341 ASTOR 0 320 261 W-13864 FGS Cuttings 29.188051 -81.049559 DAYTONA BEACH 30 190 262 W-14180 FGS Cuttings 29.371822 -81.558277 WELAKA SE 24 157 263 W-14187 FGS Cuttings 29.446532 -81.197911 FLAGLER BEACH WEST 23 160 264 W-14188 FGS Cuttings 29.446532 -81.197911 FLAGLER BEACH WEST 23 170 265 W-14189 FGS Cuttings 29.446532 -81.197911 FLAGLER BEACH WEST 23 170 266 W-14190 FGS Cuttings 29.446532 -81.197911 FLAGLER BEACH WEST 23 115 267 W-14264 FGS Cuttings 29.188051 -81.049559 DAYTONA BEACH 30 185 268 W-14315 FGS Core 29.181644 -81.713966 JUNIPER SPRINGS 48 280

PAGE 39

FLORIDA GEOLOGICAL SURVEY 36 Map ID Well Label Data Source Sample T yp e Latitude Longitude 24K Quad Elevation (ft) Total De p th (ft) 269 W-14316 FGS Core 29.147061 -81.664883 JUNIPER SPRINGS 110 140 270 W-14327 FGS Core 29.175 -81.715555 JUNIPER SPRINGS 72 112 271 W-14353 FGS Core 29.514721 -81.662585 SATSUMA 89 162 272 W-14432 FGS Cuttings 29.242616 -81.046075 DAYTONA BEACH 5 210 273 W-14623 FGS Cuttings 29.14277 -81.035394 DAYTONA BEACH 29 210 274 W-14625 FGS Cuttings 29.14277 -81.035394 DAYTONA BEACH 29 200 275 W-14751 FGS Core 29.105277 -81.655 FARLES LAKE 60 102 276 W-14763 FGS Cuttings 29.483917 -81.527712 CRESCENT CITY 0 157 277 W-14965 FGS Cuttings 29.505542 -81.291653 ESPANOLA 28 220 278 W-14966 FGS Cuttings 29.511425 -81.287819 ESPANOLA 28 220 279 W-14967 FGS Cuttings 29.500002 -81.27917 BUNNELL 27 220 280 W-14968 FGS Cuttings 29.504171 -81.266708 ESPANOLA 28 210 281 W-15109 FGS Cuttings 29.287264 -81.159063 FAVORETTA 23 200 282 W-15141 FGS Cuttings 29.112307 -81.053498 SAMSULA 25 180 283 W-15201 FGS Cuttings 28.965459 -81.655433 UMATILLA 68 368 284 W-15312 FGS Cuttings 29.083836 -82.012291 BELLEVIEW 104 240 285 W-15362 FGS Cuttings 29.207384 -81.409683 PIERSON 42 370 286 W-15635 FGS Cuttings 29.020728 -81.299304 DELAND 49 400 287 W-15651 FGS Cuttings 29.140633 -81.14964 DAYTONA BEACH NW 44 300 288 W-15772 FGS Cuttings 29.100462 -81.143198 DAYTONA BEACH SW 41 300 289 W-15780 FGS Cuttings 29.186469 -81.152616 DAYTONA BEACH NW 29 300 290 W-15835 FGS Cuttings 29.094613 -81.362092 DELAND 52 315 291 W-15862 FGS Cuttings 29.222891 -81.468786 PIERSON 41 200 292 W-15863 FGS Cuttings 29.222891 -81.468786 PIERSON 41 200 293 W-15994 FGS Cuttings 29.143395 -81.129309 DAYTONA BEACH NW 43 818 294 W-15995 FGS Cuttings 29.185305 -81.072731 DAYTONA BEACH 26 820 295 W-16007 FGS Core 29.103013 -81.315333 DELAND 90 90 296 W-16008 FGS Core 29.174972 -81.452546 PIERSON 32 90 297 W-16009 FGS Core 29.257553 -81.12047 ORMOND BEACH 21 75 298 W-16164 FGS Cuttings 29.164925 -81.153526 DAYTONA BEACH NW 36 350 299 W-16174 FGS Cuttings 29.375061 -81.917222 EUREKA DAM 68 190 300 W-16175 FGS Cuttings 29.145091 -81.145551 DAYTONA BEACH NW 44 330 301 W-16217 FGS Cuttings 29.313542 -81.105587 ORMOND BEACH 17 104 302 W-16219 FGS Cuttings 29.336666 -81.709166 SALT SPRINGS 1 200 303 W-16227 FGS Cuttings 29.27645 -81.684166 SALT SPRINGS 41 200 304 W-16278 FGS Cuttings 29.020929 -81.299259 DELAND 48 370 305 W-16280 FGS Cuttings 29.462172 -81.934722 EUREKA DAM 37 264 306 W-16557 FGS Cuttings 29.17212 -81.96295 LYNNE 70 300 307 W-16563 FGS Cuttings 28.967222 -81.979252 LADY LAKE 79 426 308 W-16801 FGS Cuttings 29.281447 -81.066859 ORMOND BEACH 7 195 309 W-16823 FGS Cuttings 29.257109 -81.114031 ORMOND BEACH 25 130 310 W-16831 FGS Cuttings 29.029145 -81.260806 DELAND 70 150 311 W-17060 FGS Cuttings 29.104148 -81.308952 DELAND 83 460 312 W-17154 FGS Cuttings 29.141944 -81.364999 LAKE DIAS 19 460 313 W-17175 FGS Cuttings 29.377782 -81.526741 CRESCENT CITY 43 400 314 W-17255 FGS Cuttings 29.390277 -81.967777 EUREKA DAM 47 44.5 315 W-17274 FGS Cuttings 29.363333 -81.684722 SALT SPRINGS 23 460 316 W-17475 FGS Cuttings 29.465833 -81.651666 WELAKA 51 16 317 W-17476 FGS Cuttings 29.463888 -81.651666 WELAKA 45 41 318 W-17477 FGS Cuttings 29.464722 -81.653055 WELAKA 30 15 319 W-17531 FGS Cuttings 29.179166 -81.0625 DAYTONA BEACH 28 970 320 W-17532 FGS Cuttings 29.097777 -81.273888 DELAND 49 140 321 W-17537 FGS Cuttings 29.097777 -81.273888 DELAND 49 66 322 W-17561 FGS Cuttings 29.429693 -81.858975 LAKE DELANCY 140 136 323 W-17562 FGS Cuttings 29.091944 -81.708611 FARLES LAKE 92 81

PAGE 40

OPEN-FILE REPORT 101 37 Map ID Well Label Data Source Sample T yp e Latitude Longitude 24K Quad Elevation (ft) Total De p th (ft) 324 W-17563 FGS Cuttings 29.268333 -81.82 LAKE KERR 140 96 325 W-17564 FGS Cuttings 29.282499 -81.770833 LAKE KERR 67 76 326 W-17565 FGS Cuttings 29.360833 -81.856944 LAKE KERR 131 81 327 W-17566 FGS Cuttings 29.105277 -81.813055 LAKE MARY 112 101 328 W-17568 FGS Cuttings 29.298055 -81.696666 SALT SPRINGS 41 126 329 W-17569 FGS Cuttings 29.471111 -81.860277 LAKE DELANCY 163 91 330 W-17659 FGS Cuttings 28.968055 -82.011666 OXFORD 68 101 331 W-17660 FGS Cuttings 29.354429 -81.46245 SEVILLE 27 25 332 W-17686 FGS Cuttings 29.032202 -81.556458 ALEXANDER SPRINGS 46 91 333 W-17764 FGS Core 29.3208 -81.179199 FAVORETTA 23 151 334 W-18061 FGS Cuttings 29.499166 -81.958333 EUREKA DAM 81 141 335 W-18250 FGS Cuttings 29.284722 -81.126388 FAVORETTA 25 90 336 W-18267 FGS Cuttings 29.386111 -81.972777 EUREKA DAM 56 180 337 W-18279 FGS Cuttings 29.428611 -81.856388 LAKE DELANCY 139 380 338 W-18281 FGS Cuttings 29.321666 -81.539444 WELAKA SE 20 110 339 W-18284 FGS Cuttings 29.251666 -81.507222 WELAKA SE 12 170 340 W-18287 FGS Cuttings 29.431944 -81.513888 CRESCENT CITY 37 160 341 W-18297 FGS Cuttings 29.499166 -81.958333 EUREKA DAM 81 210 342 W-18814 FGS Core 29.176666 -81.116666 DAYTONA BEACH 28 1006 343 W-18825 FGS Cuttings 29.508055 -81.161944 BEVERLY BEACH 18 290 344 W-18863 FGS Core 29.211111 -81.086944 DAYTONA BEACH 28 1000 345 W-18998 FGS Core 29.068058 -81.289174 DELAND 72 870 346 W-19036 FGS Core 29.169166 -81.641943 JUNIPER SPRINGS 67 195 347 W-19060 FGS Core 29.411361 -81.305111 BUNNELL 13 92 348 W-19213 FGS Core 29.431916 -81.513911 CRESCENT CITY 37 112 349 W-19240 FGS Core 29.091389 -81.044167 SAMSULA 23 810


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Title:
Text to accompany geologic map of the USGS Daytona Beach 30 x 60 minute quadrangle, northeast Florida (Open-File Map Series 105)
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iv, 58 p.
Language:
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Creator:
Green, Richard C.
Publisher:
Reston, VA; Florida Geological Survey
Publication Date:

Subjects

Subjects / Keywords:
Flagler County, Floirda
Lake County, Floirda
Marion County, Florida
Putnam County, Florida
Volusia County, Florida
Genre:
Spatial Coverage:

Notes

General Note:
Added Entries: Evans, William L., III Bassett, Seth W.
General Note:
Web Pages or Sites: http://www.dep.state.fl.us/geology/statemap/index.html http://ngmdb.usgs.gov/Prodesc/proddesc%5F98759.htm http://publicfiles.dep.state.fl.us/FGS/FGS%5FPublications/OFR/OFR101%5FFINAL.pdf
General Note:
Series: FGS Open-File Report; 101

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University of Florida
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University of Florida
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All rights reserved by the source institution.
Resource Identifier:
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AA00018708:00001

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  • STANDARD VIEW
  • MARC VIEW
MISSING IMAGE

Material Information

Title:
Text to accompany geologic map of the USGS Daytona Beach 30 x 60 minute quadrangle, northeast Florida (Open-File Map Series 105)
Physical Description:
iv, 58 p.
Language:
English
Creator:
Green, Richard C.
Publisher:
Reston, VA; Florida Geological Survey
Publication Date:

Subjects

Subjects / Keywords:
Flagler County, Floirda
Lake County, Floirda
Marion County, Florida
Putnam County, Florida
Volusia County, Florida
Genre:
Spatial Coverage:

Notes

General Note:
Added Entries: Evans, William L., III Bassett, Seth W.
General Note:
Web Pages or Sites: http://www.dep.state.fl.us/geology/statemap/index.html http://ngmdb.usgs.gov/Prodesc/proddesc%5F98759.htm http://publicfiles.dep.state.fl.us/FGS/FGS%5FPublications/OFR/OFR101%5FFINAL.pdf
General Note:
Series: FGS Open-File Report; 101

Record Information

Source Institution:
University of Florida
Holding Location:
University of Florida
Rights Management:
All rights reserved by the source institution.
Resource Identifier:
System ID:
AA00018708:00001

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Table of Contents
    Front Cover
        Front Cover
    Table of Contents
        Page i
    List of Figures
        Page ii
    Abstract and introduction
        Page 1
        Page 2
        Page 3
        Page 4
    Geologic summary
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
    Lithotratigraphic units
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
    Hydrogeology and geophysical logging
        Page 21
        Page 22
        Page 23
    Derivative products
        Page 24
    References
        Page 25
        Page 26
        Page 27
        Page 28
    Acknowledgement
        Page 29
        Page 30
    Appendix A: FGS wells utilized for study
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
Full Text





STATE OF FLORIDA


DEPARTMENT OF ENVIRONMENTAL PROTECTION
Herschel T. Vinyard Jr., Secretary

REGULATORY PROGRAMS
Jeff Littlejohn, Deputy Secretary

FLORIDA GEOLOGICAL SURVEY
Jonathan D. Arthur, State Geologist and Director


OPEN-FILE REPORT 101

Text to accompany geologic map of the
USGS Daytona Beach 30 x 60 minute quadrangle, northeast Florida
(Open-File Map Series 105)

By

Richard C. Green, William L. Evans, III and Seth W. Bassett


2013
ISSN 1058-1391

This geologic map was funded in part by the USGS National Cooperative Geologic Mapping
Program under assistance award number G12AC20412 in Federalfiscal year 2012









TABLE OF CONTENTS

L ist o f F ig u re s ........................................................................................................................................... ii

A b stra c t .......................................................................................... 1

Introduction..................................................... ............... 1
M eth o d s ...................................................................... . . 3
P reviou s W ork .......................................................... ........ 5

G eologic Sum m ary ..... . ................................................................................................ ...... .......... 5
S tru c tu re ................... ................... ...................7..........
Geom orphology ................................................................. ........ 9
Barrier Island Sequence District ............... ........ ......... 10
Atlantic Coastal Com plex ................... .......... ........................................ 10
Lower St. Johns River Valley ............. .............. .................... 11
Central Lakes D district ............. .................................................................... ....... 11
Crescent City R idge ............. ............................................................... .................... 11
D eL and R idge ............. ......... ............................................................. ...... 12
Fort M cC oy Plain............................ .................... 12
M t. D ora R idg e ........................................................... ........ ...... 12
Ocklawaha River Valley ................................. ........................... ........... 12
St. Johns River O offset ............. .............................................................. ................. 13
O cala K arst D district ................................................................................... .............. 13
O cala K arst H ills............................. .............. ...... 14

Lithotratigraphic Units ............... .......... ......................................................................................... 14
T e rtia ry S y stem .......................................................................................................................... 14
E ocene Series............................. ............... ..... 14
Avon Park Formation....................... .. ........ 14
O cala L im eston e ................................................................... 15
M io c en e S erie s ............... ................................................................................ .............. ...... 16
H aw thorn G group ................................................................... 16
Penney Farms Formation .. ... ........ .................. .............. 16
Marks Head Formation .......................................... 17
C oosaw hatchie Form ation........................................................................ ......... 17
Hawthorn Group (Undifferentiated) ........................................ ... ........... 17
Tertiary/Quatem ary System s............................. .................... 18
Pliocene/Pleistocene Series............................. .............. 18
Cypresshead Form ation ......................................... .............. 18
Pliocene/Pleistocene Shelly Sediments ..................................... 19
Tertiary/Quatemary Dunes .......................................... 19
Pleistocene to Holocene Series ...... .................. ........ ........ 20
A nastasia Form ation ................................................. 20
Undifferentiated Quaternary Sediments .................................. .......... 20









Q uaternary B each R idge and D une......................................................... ... ................. 20
Holocene Sediments ....................................... .................. 21

H y d ro g eolog y ............................................................................ 2 1

G eophysical L jogging ............... .. ............................................................21
Stratigraphy and Gamma-Ray Log Interpretation ........................................................ 22
A von Park F orm ation........................................... .................. .. .. .......... .. .............. 22
O cala L im eston e ................................................................... 2 3
H aw thorn G group .............. ......................... .............. ...... 23
Pliocene/Pleistocene shelly sediments............. ............ ......... ...... .................. 24
Cypresshead Formation and Tertiary/Quaternary dune sediments................................... 24

D eriv ativ e P ro d u cts .................................................................................................... ......................2 4

R e fe re n c e s ................................................... ................. ......................................................................... 2 5

A ck n ow led g em en ts ............... .................................................................................................................2 9

A appendix A : FG S W ells U utilized For Study ................................................. ........................... 31


LIST OF FIGURES

Figure 1. Nearby areas mapped under the FGS STATEMAP Program........................................ 2
Figure 2. FGS cores (squares), cuttings (circles) and St. Johns River Water Management District
geophysical logs (triangles) utilized for top of rock models. See discussion starting on
page 14 for lithostratigraphic unit abbreviations and descriptions. ................................. 4
Figure 3. Location of selected river basins, springs, swallets and other water bodies ................. 6
Figure 4. Principal subsurface structures of north Florida (modified from Scott, 1988)................ 8
Figure 5. Terraces in the study area (after Healy, 1975). ............................................................ 9
Figure 6. Gamma Log ofW-19451 (see OFMS 105, plate 2, B-B')........................................ 22






OPEN-FILE REPORT 101


Text to accompany geologic map of the
USGS Daytona Beach 30 x 60 minute quadrangle, northeast Florida
(Open File Map Series 105)

Richard C. Green (P.G. # 1776), William L. Evans, III and Seth W. Bassett

ABSTRACT

The accompanying 1:100,000 scale geologic map (Open-File Map Series 105, Plate 1)
depicts the areal distribution of bedrock and surficial geologic units for the U.S. Geological
Survey (USGS) Daytona Beach 30 x 60 minute quadrangle. The map was constructed using a
combination of field mapping (at 1:24,000 scale), compilation of data from existing maps
(various scales), core and cuttings analyses and descriptions, geophysical log analyses and
analyses of various Geographic Information System (GIS) data sources. The resulting data were
compiled in ESRI ArcGIS ArcMapTM 10 software for publication as part of the Florida
Geological Survey Open-File Map Series. Mapped units range from Middle Miocene to
Quaternary. Important resources in the mapped area include potable groundwater, springs, sand,
clay, and coquina. Numerous springs, swallets (sinking streams), and other karst features are
present in the study area. The geologic maps produced for this area not only provide a greater
understanding of the interaction between the geologic units, associated karst, springs and
ecosystems, but have utility as a land management tool for economic development, mineral and
energy production, and environmental protection for Florida. Examples include designing new
construction projects, siting new water supply wells, energy production facilities, waste
management and storage facilities, locating sources of mineable resources for aggregate supply,
and protection of springs, surface and groundwater quality.

Keywords: Florida, geologic map, Avon Park Formation, Ocala Limestone, Hawthorn
Group, Penney Farms Formation, Marks Head Formation, Coosawhatchie Formation,
Cypresshead Formation, Anastasia Formation, geomorphology, hydrogeology, springs, swallets,
karst, sinkholes, Floridan aquifer system, Flagler County, Lake County, Marion County, Putnam
County, Volusia County, Daytona Beach.

INTRODUCTION

Florida Geological Survey (FGS) Open-File Report (OFR) 101 accompanies Open-File
Map Series (OFMS) 105, which is comprised of three plates. Plate 1 depicts the near-surface
geology of the USGS Daytona Beach 30 x 60 minute quadrangle on a digital elevation model
(DEM). Plate 2 depicts five geologic cross-sections, a stratigraphic correlation chart, and
representative photos for several of the lithologic units in the study area. Plate 3 is a
geomorphology map on a DEM, showing locations of known springs, sinkholes and swallets,
along with photographs of selected exposures within the study area.
The study area is located along the Atlantic coastline of Florida (Figure 1). It includes the
communities of Daytona Beach, DeLand, Flagler Beach and Ormond Beach. The quadrangle,
which includes portions of Flagler, Lake, Marion, Putnam and Volusia Counties, is bounded to
the west by the USGS Ocala 30 x 60 minute quadrangle, recently mapped under the
STATEMAP program (Green et al., 2009a; Green et al., 2009b; Green et al., 2010a; Green et al.,







FLORIDA GEOLOGICAL SURVEY


2010b), to the north by the USGS Saint Augustine 30 x 60 minute quadrangle and to the south by
the USGS Orlando 30 x 60 minute quadrangle (Figure 1). The Tomoka, St. Johns, and
Ocklawaha Rivers, along with numerous creeks and springs, occur in the map area. Recharge to
and discharge from the Floridan aquifer system (FAS) occurs throughout the study area. The
FAS is the primary source of water for springs and drinking water in the region.
One objective for this report is to provide basic geologic information for the
accompanying OFMS 105. Information provided by this report and the plates in OFMS 105 is
intended for a diverse audience of professionals in geology, hydrology, engineering,
environmental and urban planning, and laypersons, all of whom have varying levels of geologic
knowledge. The maps can help users identify and interpret geologic features which impact
activities related to groundwater quality and quantity, as well as aid in locating mineral
resources, land-use planning and construction project design. Applied uses of the maps and data
in this report include: 1) identifying potential new mineral resources, 2) characterizing zones of
potential aquifer recharge and confinement, 3) aiding water-management decisions on
groundwater flow and usage, 4) providing information on aquifer vulnerability to potential
pollution, 5) ecosystem, wetlands and environmental characterization, and 6) recreational uses.


0 10 20 40 60 MI

0 15 30 60 90 KM


City
----- County boundary
S11:100.000 quadrangle
Current STATEMAP study area
= Daytona Beach, OFMS 105, 2013
STATEMAP completed maps
Gainesville West, OFMS 93, 2004
Gainesville East, OFMS 94. 2004
SOcala East. OFMS 100, 2009
Ocala West. OFMS 101, 2010
Inverness East, OFMS 102. 2011
Inverness West, OFMS 103, 2012


Figure 1. Nearby areas mapped under the FGS STATEMAP Program.






OPEN-FILE REPORT 101


Methods

Mapping efforts consisted of: 1) reviewing and compiling existing geologic literature and
data, 2) mapping geologic units in the field at 1:24,000 scale using standard techniques, 3)
analyses of existing core and cuttings samples from the FGS sample repository, 4) new core
drilling, 5) collecting and describing outcrop samples, and 6) preparing a geologic map,
geological cross-sections and geomorphic map of the area. Fieldwork, performed during the fall
of 2012 through the summer of 2013, consisted of sampling and describing numerous outcrops,
river and borrow pit exposures.
Forty-three new samples of geologic material were added to the FGS surface-sample
archives (M-Series) and five cores (1,294 feet or 394.4 meters total) were drilled for the project.
Approximately 100 outcrops and exposures were also examined during the project. In addition to
new cores collected for this study, approximately 350 sets of cores and cuttings archived in the
Florida Geological Survey well repository were examined and formation picks were made for
mapped geologic units. Over four hundred formation picks derived from geophysical logs (see
discussion beginning on page 21 for geophysical log interpretation), in addition to the data from
the cores and cuttings, were utilized in developing various modeled surfaces. Figure 2 shows the
locations of FGS cores and cuttings and St. Johns River Water Management District (SJRWMD)
data points within the study area. Appendix A includes FGS wells with core and/or cuttings
samples which were examined by the authors and used for the top of rock model or for
determining the geologic surface and subsurface formations. An interpolated top of rock surface
was developed using kriging along with a Digital Elevation Model (DEM) to generate an
overburden thickness model. The map and accompanying plates were developed in ESRI
ArcGIS ArcMapTM 10 software for publication as part of OFMS 105.
Due to a lack of complete LiDAR coverage in the study area, a custom elevation model
was created for this product. Two products were used to create this elevation model: standard
LiDAR elevation models with horizontal resolutions of five feet (1.5 meters); and a much
coarser elevation model based off of topographic contours with a horizontal resolution of 100
feet (30.5 meters). LiDAR coverage currently exists for the entirety of Lake, Marion, and
Volusia counties, in addition to a small portion of Putnam County along the St. John's River
Corridor, and a swath of the coastal areas of Volusia County approximately three miles wide.
The majority of both Volusia and Putnam counties lacked LiDAR coverage.
The hybrid elevation model was created by first combining all of the existing LiDAR
elevation models into a single raster. The coarser 100 foot (30.5 meter) contour-based DEM was
re-sampled and aligned to match the resolution of the five feet (1.5 meter) LiDAR elevation
models. A conditional statement was then used in ArcGIS to create a new hybrid raster by
selecting an elevation value from the LiDAR coverage if available; where LiDAR was not
available, elevation values were drawn from the coarser, contour based DEM.
As a preliminary step, points from each of the datasets (cores, cuttings and geophysical
logs) were used to generate a Triangular Irregular Network (TIN) of the modeled surface. This
TIN was then used as a method of examining and discarding any points that appeared anomalous
compared to their surrounding values. During this step, any point which differed substantially
from the surrounding points were indicated by a sharp depression or peak in the TIN surface;
points found that differed by 75 or more feet from surrounding points were then removed from
the dataset.






FLORIDA GEOLOGICAL SURVEY


After this step was completed, an ordinary kriging method was used to generate a top of
rock surface using the "stable" algorithm. Lag size was empirically calculated based on the total
spatial extent of the combined datasets, and then adjusted slightly to improve model
performance. The error values for all data were examined after each iteration of the model, and
any points with a standardized error greater than five or less than negative five were discarded in
order to improve the final model performance.


o - ., .. '., -" o i



-u 2. FGS o (sq'ua-re s) utig (.rcl) n J ., W t M\ a
7' V










Much of the study area is blanketed by a veneer of undifferentiated Tertiary and












unit. If these undifferentiated sediments are less than 20 feet (6.1 meters) thick, then the
^ ^. .. *.:/c o o o\o


























wells nearby.
-..I.," o o.

























mapped area is hindered by the presence of numerous wetlands, farms, ranches and privately
owned land. Additionally, much of the coastal area is heavily developed with sub-divisions,
geologic ui w i 2 .et,.1 m of th surface. If T i d (T'-





.undiffrentae Q uat corn (sare ), cuttings (ci ) and ..t. Johns Ri dge .a- e ana duntQ









uit.s If these geophyresicate slogs (trianless tiiand fr tp ofee (6 moeersl tie scstione the

105,mPlated 1) theologi area is blankset e of 105, Pla neer mfa appearance ed Terivtely






owned land. Additionally, much of the coastal area is heavily developed with sub-divisions,
geolog c. untwti 0fe 61mtes ftesrae fTrtayQaenr ue(;)






OPEN-FILE REPORT 101


many of which are gated communities. In instances where access was limited by these factors,
the authors had to rely on existing well and core data. Fieldwork access was typically limited to
public roads, State-owned lands and County-owned lands.

Previous Work

The current study builds on many previous geologic investigations in and around the
present map area which were useful in preparing this report. Preliminary county geologic maps
for Flagler (Scott, 1992b), Lake (Scott, 1992d), Marion (Scott, 1992e), Putnam (Scott, 1992a),
and Volusia (Scott, 1992c) counties at 1:126,720 scale were previously published by the FGS.
However, each of these geologic maps were constructed in an average time-frame of two weeks
utilizing selected in-house geologic data with little-to-no extra field work. Although these maps
provided a starting point for the detailed geologic mapping undertaken for this project,
significant refinement of prior geologic maps was possible as a result of this project. A statewide
geologic map (Scott et al., 2001) also provided a framework for the current, more detailed
mapping.
Scott (1988) published detailed descriptions, structure contour maps, and isopach maps
for units of the Hawthorn Group. Huddlestun (1988) defined and discussed the Nashua and
Cypresshead Formations. This study also benefited greatly from the work performed during
geologic mapping of the eastern portion of the USGS Ocala 30 x 60 minute quadrangle (Green et
al., 2009a; Green et al., 2009b). Some of the field relationships and stratigraphic problems were
worked out during those projects and data gathered during work on them proved invaluable to
the completion of this project.

GEOLOGIC SUMMARY

The near surface geology of the USGS 30 x 60 minute Daytona Beach quadrangle is
composed of a complex mixture of Middle Eocene to Quaternary carbonate and siliciclastic
sediments. A combination of factors, including fluvio-deltaic deposition, marine deposition,
dissolution of underlying carbonates (karstification), erosion of sediments as a result of eustatic
changes in sea level and structural features have influenced the geology of the study area.
The oldest unit to crop out in the Daytona Beach quadrangle is the Tertiary
Coosawhatchie Formation of the Hawthorn Group (Thc). This unit is exposed in the vents of
Marion Salt Spring, Juniper Spring and Alexander Spring (see OFMS 105, Plate 1).
Detailed description of the lithology of all units found in the study area begins on page 14
of this publication. Along with lithologic descriptions, several diagnostic foraminifera and
echinoids aid in distinguishing Ocala Limestone from the Avon Park Formation. The Avon Park
Formation contains Cushmania [Dictyoconus] americana and Discorinopsis gunteri which are
not found in the Ocala Limestone. The occurrence ofNummulites spp. and Lepidocyclina spp. in
the Ocala Limestone helps to distinguish it from the Avon Park Formation in the mapped area.
Much of the Daytona Beach quadrangle is located within the Ocklawaha, Tomoka, and
St. Johns River Basins (Figure 3). There are numerous springs and spring-fed rivers within the
study area, including two springs in Lake County, thirty-seven springs in Marion County, nine
springs in Putnam County and one in Volusia County. These include twelve first magnitude
springs and thirty-seven lesser magnitude springs (Scott et al., 2004). A first magnitude spring is
defined as having a minimum average flow of at least 100 cubic feet per second (64.6 million
gallons per day; Copeland, 2003).







FLORIDA GEOLOGICAL SURVEY


Portions of the recharge areas for many of the aforementioned springs in Lake, Marion,
Putnam and Volusia counties are located within the study area. Many of these springs have
shown significant increases in pollutants in the last few decades, particularly nitrate (Phelps,
1994; Phelps, 2004; Jones et al., 1996; Scott et al., 2002; Upchurch et al., 2004; Copeland et al.,
2009). Detailed geologic mapping of lithostratigraphic units in this area provides critical data
needed for future assessments of the vulnerability of the aquifer systems and springs to
contamination. Understanding the surficial geology of the map area is a key factor in developing
management and protection plans, not only for the springs, but for the unconfined portions of the
Floridan aquifer system.


0 10 20 40 60 MI

0 15 30 60 90 KM


0- 1st magnitude spring
e- Other magnitude spring
Swallet
| Lake or pond
River
I | 1:100,000 quadrangle
OFMS 105, 2013
I Current STATEMAP
Study Area


Crystal River to St. Petersburg Basin
SMiddle East Coast Basin
SUpper East Coast Basin
SKissimmee River Basin
m Ocklawaha River Basin
I| Santa Fe River Basin
Lower St. Johns River Basin
j Upper St. Johns River basin
Lower Suwannee River Basin
SWaccasassa River Basin
South Withlacoochee River Basin


Figure 3. Location of selected river basins, springs, swallets and other water bodies.






OPEN-FILE REPORT 101


Karst processes have extensively modified the topography of the region, and continue to
actively shape it today. Karst topography is characterized by solutional features, subterranean
drainage, and caves (Poucher and Copeland, 2006). Downward infiltration of slightly acidic rain
and surface water through preferential pathways, such as joints, fractures, and bedding planes,
combined with groundwater fluctuations, cause dissolution of the carbonate rocks (Waltham et
al., 2005).
The variability of the karst observed within the study area is closely related to the
thickness of overburden and the presence/absence of Cypresshead Formation and Hawthorn
Group clays within the overburden mantling the region's carbonate rocks. Those clays are often
the sediments which create a bridge over any cavities which have formed within the carbonates.
The study area can be divided into two main karst regions: the areas upon the Mt. Dora
Ridge and the areas surrounding it. Generally, the overburden sediments are thickest and contain
a higher percentage of clay and clayey sediments, resulting more frequently in the occurrence of
cover-collapse sinkholes to the west and south of the Mt. Dora Ridge. To the east of the Mt.
Dora Ridge, extending towards the St. Johns River valley, the overburden sediments are
generally thinner (see OFMS 105, Plate 2) resulting in both cover-subsidence and cover-collapse
sinkholes (Sinclair and Stewart, 1985). Several wells examined in this study located on the flanks
of the Mt. Dora Ridge exhibited the effects of that increased karstification. The samples for those
wells typically exhibited increased amounts of sand, organic and clayey sand interspersed with
occasional bits of carbonate rock at depth followed by a correspondingly deeper-than-expected
top of first carbonate rock unit. One well drilled for this project (W-19453; OFMS 105, Plate 2,
cross-section C-C'), demonstrates this. The well had significantly thicker Cypresshead Formation
and thinner Hawthorn Group sediments than expected. Possible explanations include karst or
filling in of an erosional low in the top of the Hawthorn Group surface. Unfortunately, well
control in this area was inadequate to determine the nature of the surface.

Structure

Several structural features have affected the geology of the region (Figure 4). The
Peninsular Arch, a structurally high area which affected deposition from the Cretaceous to the
early Cenozoic, is the dominant subsurface feature of the Florida peninsula (Applin and Applin,
1944; Applin, 1951; Puri and Vernon, 1964; Williams et al., 1977; Schmidt, 1984; Miller, 1986;
Scott, 1997). The axis of the Peninsular Arch, which cuts through the western portion of the
study area, extends from southeastern Georgia to the vicinity of Lake Okeechobee in southern
Florida in a general northwest to southeast trend. The crest of the arch passes beneath Alachua
County and is highest in Union and Baker counties northwest of the study area. The arch was a
topographic high during most of the Cretaceous Period and had Upper Cretaceous sediments
deposited upon it (Applin, 1951). It formed a relatively stable base for Eocene carbonate
deposition (Williams et al., 1977). The arch did not affect mid-Tertiary to Holocene sediment
deposition (Williams et al., 1977; Scott, 1997).
The Sanford High, named by Vernon (1951), is a positive feature located in Volusia and
Seminole counties. It is a prominent structure affecting the near surface depositional and post-
depositional environments within the map area (Figure 4). Vernon (1951) described this feature
as "a closed fold that has been faulted, the Sanford high being located on the upthrown side".
The Ocala Limestone and Hawthorn Group are missing over this feature and post-Hawthorn
Group sediments (undifferentiated Pliocene/Pleistocene shelly sediments) directly overlie the
Avon Park Formation in the vicinity of the Sanford High (see OFMS 105, Plate 2).






FLORIDA GEOLOGICAL SURVEY


The St. Johns Platform, introduced by Riggs (1979a, 1979b), extends northward from the
Sanford High into St. Johns County. This platform, which is expressed on the erosional surface
of the Ocala Limestone, dips gently north-northwest towards Jacksonville (Scott, 1983). This is
evident throughout the map area (OFMS 105; Plate 2). Undifferentiated sediments, thickest on
the flanks of the Mt. Dora, DeLand and Crescent City ridges, have subsequently been deposited
on the exposed undifferentiated Pliocene/Pleistocene shelly sediments, Miocene Hawthorn
Group and Eocene carbonates. These consist of residual clays, sands, and aeolian sands
deposited during the Miocene to Holocene (Scott, 1997).


WE
N




S



SOFNIS 105 study area





0 25 50 100 150 200 Miles


HIGH


0 45 90


270


360 Kilometers


Figure 4. Principal subsurface structures of north Florida (modified from Scott, 1988).






OPEN-FILE REPORT 101


Geomorphology

Healy (1975) recognized six possible marine terraces within the study area (Figure 5)
based upon elevations above mean sea level (MSL): the Silver Bluff terrace at elevations
between 1 and 10 feet (0.3 and 3 meters), the Pamlico terrace at elevations between 10 and 25
feet (3 and 7.6 meters), the Talbot terrace at elevations between 25 and 42 feet (7.6 and 12.8
meters), the Penholloway terrace at elevations between 42 and 70 feet (12.8 and 21.3 meters), the
Wicomico terrace at elevations between 70 to 100 feet (21.3 to 30.5 meters) and the
Sunderland/Okefenokee terrace at elevations between 100 and 170 feet (30.5 and 51.8 meters).
Detailed discussions and correlations of these marine terraces and relict shorelines have been
attempted by many authors, including Matson and Sanford (1913), Cooke (1931, 1939), Flint
(1940, 1971), MacNeil (1950), Alt and Brooks (1965), Pirkle et al. (1970), Healy (1975), and
Colquhoun et al. (1991).


















Fig Relief of Terraces, in Feet
EI~170 215 Coharie terrace
100 170 Sunderland/
Okefenokee Terrace
70 100 Wicomico terrace
42 70 Penholloway terrace
25 42 Talbot terrace








districts: the Barrier Island Sequence District, the Central Lakes District and the Ocala Karst
District (OFMS 105; Plate 3, Figure 2). These districts are further subdivided into terranes
(OFMS 105; Plate 3, Figure 3) by Scott et al., (in preparation).
(OFMS 105; Plate 3, Figure 3) by Scott et al., (in preparation).






FLORIDA GEOLOGICAL SURVEY


Barrier Island Sequence District

The Barrier Island Sequence District extends into Florida from Georgia. The district is
characterized by beach ridges, dunes and paleo-lagoons. The district extends from the Florida-
Georgia state line southward to the vicinity of Lake Okeechobee. It lies to the east of the
Okeefenokee Basin District, the Ocala Karst District, the Central Lakes District, and the Sarasota
River District. It lies north of the Everglades District (OFMS 105, Plate 3, Figure 2). Elevations
within the District range from sea level to more than 145 feet (44.2 meters) above MSL. The
surficial and shallow subsurface sediments of the district were deposited during the Plio-Pleistocene
and lie unconformably on sediments ranging from the Middle Eocene Avon Park Formation to the
Oligocene-Miocene Hawthorn Group.
Beach ridge plains occur in several areas of the Barrier Island Sequence District at
elevations ranging from near sea level to more than 75 feet (22.9 meters) above MSL. In the study
area, these occur on the Atlantic Coastal Complex and portions of the Lower St. Johns River Valley.
Drainage patterns in these areas may be strongly controlled by the relict beach ridges forming, in
some cases, a distinct trellis drainage pattern. The beach ridge swales are often swampy and control
the development of lakes on portions of the Osceola Plain.
The Barrier Island Sequence District contains relict (or paleo) lagoons. The occurrence of
the lagoonal features is most prominent in the southern portion of the district in the headwaters of
the St. Johns River. White (1970) thought that this area was not a paleo-lagoon but a beach ridge
plain that had been reduced in stature by dissolution of incorporated shell material. He stated that
there were relict beach ridges in the area and that the ridges controlled the drainage. Modem
topographic maps, however, do not show the beach ridges nor do they reveal a drainage pattern
indicative of beach ridges.
This paleo-lagoon lies between the Atlantic coast on the east and a prominent erosional
scarp on the west. The scarp toe occurs at approximately 30 feet (9.1 meters) above MSL and
extends nearly continuously from the southern-most portion of the Barrier Island Sequence District
northward to the Florida-Georgia state line. The paleo-lagoon extends uninterrupted from the
southern end of the district to southern Volusia County. Northward from southern Volusia County
the relict lagoon is either interrupted or partially covered by beach ridges. However, the lagoon can
be recognized as far north as the vicinity of Jacksonville in Duval County.

Atlantic Coastal Complex

The Atlantic Coastal Complex extends from the Florida-Georgia line to northern Brevard
County (OFMS 105, Plate 3, Figure 3). In the study area, the terrane consists of Pliocene through
recent barrier beach ridges and dunes that are consistent with the terrane as a whole. Elevations
range from sea level to 90 feet (27.4 meters) above MSL. Within the mapped area, elevations
range from sea level to approximately 50 feet (15.2 meters) above MSL. There are multiple coast
parallel creeks and swamps in the swales separated by ridges and broad scale development of
trellis drainage. Some of the major water features include the Tomoka River, Spruce Creek,
Graham Swamp and the Halifax River. The latter two, made more distinct by construction of the
Intracoastal Waterway, separate the modern barrier island from the mainland to the west. In the
study area, the terrane has varying thickness of undifferentiated Quaternary, undifferentiated
Tertiary and Quaternary shelly sediments and outcrops of the Pleistocene Anastasia Formation
near the Atlantic coast (OFMS 105, plate 2).






OPEN-FILE REPORT 101


Lower St. Johns River Valley

The Lower St. Johns River Valley has been hypothesized by Scott (2013, personal
communication) as part of a paleo-lagoon. The relict lagoon feature extends nearly continuously
from the headwaters of the St. Johns River in Palm Beach County to central Duval County. In
Volusia County, the paleo-lagoon is either partially interrupted or partially covered by beach
ridges. In this area, the Atlantic Coastal Complex separates the Upper St. Johns River Valley
from the Lower St. Johns River Valley (OFMS 105, Plate 3, Figure 3). The southern end of this
interruption corresponds to the westward turn of the St. Johns River as it occupies the St. Johns
River Offset. The southern end of the Lower St. Johns River Valley includes Crescent Lake and
extends northward to central Duval County where the St. Johns River turns east toward the
Atlantic Ocean and some beach ridge uplands separate the St. Johns River Valley from the
drainages associated with the Nassau and St. Marys Rivers. Elevations of the terrane range from
sea level to more than 80 (24.4 meters) above MSL. Within the study area, elevations range from
sea level to 45 feet (13.7 meters) above MSL. Variable thicknesses of undifferentiated
Quaternary sediments lie on undifferentiated Pliocene/Pleistocene shelly sediments or the
Hawthorn Group in the terrane.

Central Lakes District

The Central Lakes District occupies most of the Central Highlands of Cooke (1939) in
peninsular Florida. The district extends from eastern Alachua County, southeastern Bradford
County and southern Clay County to southernmost Highlands County. The Central Lake District
lies east and south of the Ocala Karst District, south of the Okefenokee District, west of the Barrier
Island Sequence District and north of the Sarasota River District and the Everglades District (OFMS
105; Plate 3, Figure 2). A thick (up to 200 feet [61 meters]) sequence of siliciclastic and carbonate
sediments of the Hawthorn Group, siliciclastic sediments of the Cypresshead Formation and
undifferentiated siliciclastic sediments overlie the Ocala Limestone in the district. Dissolution of
the limestone and subsequent subsidence or collapse has created the characteristic rolling hills,
sinkhole lakes and dry sinks that dominate the landscape. Much of the terrane is internally drained
due to the karst features and the permeable sand cover. District-wide elevations range from near sea
level to over 300 feet (91.4 meters) above MSL. Within the mapped area, elevations vary from near
sea level in the St. Johns River Offset to more than 200 feet (61 meters) above MSL on the Mt.
Dora Ridge. In the study area, the Central Lakes District includes the Crescent City Ridge, the
DeLand Ridge, the Fort McCoy Plain, the Mt. Dora Ridge, the Ocklawaha River Valley and the St.
Johns River Offset. These ridge features were once part of a more extensive Cypresshead Formation
upland that subsequently was erosionally altered leaving the remnant highs.

Crescent City Ridge

The Crescent City Ridge lies in northwestern Volusia County and southeastern Putnam
County (OFMS 105, Plate 3, Figure 3). It is located between the St. Johns River Offset and the
Lower St. Johns River Valley. Crescent Lake lies at the eastern toe of the ridge. The lake likely
represents a portion of the paleo-course of the ancestral St. Johns River, abandoned when the
river began to occupy the offset. Elevations vary from approximately 25 feet (7.6 meters) to 125
feet (38.1 meters) above MSL. Locally, relief on the ridge approaches 50 feet (15.2 meters). The






FLORIDA GEOLOGICAL SURVEY


terrain is a rolling, karstic landscape with closed-basin lakes. A thin sequence of Quaternary sand
overlies the Cypresshead Formation and undifferentiated Pliocene/Pleistocene shelly sediments.
The Hawthorn Group is absent under the ridge within the mapped area.

DeLand Ridge

The DeLand Ridge occurs in western Volusia County extending north-south from near
the Flagler County boundary to the Seminole County line (OFMS 105, Plate 3, Figure 3).
Elevations on the DeLand Ridge vary from approximately 20 feet (6.1 meters) to more than 100
feet (30.5 meters) above MSL within the mapped area and statewide. Locally, relief on the ridge
approaches 50 feet (15.2 meters). The terrain is a rolling karstic landscape with closed basin lakes.
A paleo-sand dune field occurs in the south-central portion of the ridge. The DeLand Ridge lies
on top of the Sanford High. In portions of Volusia County, the Hawthorn Group and the Ocala
Limestone are absent due to erosion and Cypresshead Formation and undifferentiated
Pliocene/Pleistocene shelly sediments lie on the Middle Eocene Avon Park Formation. Thin
remnants of the Ocala Limestone are present under limited portions of the DeLand Ridge.

Fort McCoy Plain

The Fort McCoy Plain is a relatively flat, poorly to moderately drained area just east of
the Ocala Karst Hills and southeast of the Hawthorne Lakes Region (OFMS 105; Plate 3, Figure
3). Scattered sinkholes are present within the terrane and elevations range from approximately 40
feet (12.2 meters) to approximately 90 feet (27.4 meters) above MSL within the study area. The
Fort McCoy Plain is underlain by sediments of the Hawthorn Group, which are mantled with
variable thicknesses of undifferentiated Quaternary sediments (Scott et al., 2001; Green et al.,
2009a; Green et al., 2009b).
Mt. Dora Ridge
The Mt. Dora Ridge occurs in the western portion of the study area in Marion, Putnam
and Lake counties. The terrain is a rolling karstic landscape with numerous lakes. Elevations on
the Mt. Dora Ridge statewide and within the mapped area vary from 10 feet (3 meters) to more
than 200 feet (61 meters) above MSL. Relief often exceeds 100 feet (30.5 meters). Karst
processes acting through a thick sequence of siliciclastic sediments (deep-cover karst) created the
landscape. Dissolution of the Ocala Limestone and carbonates within the Hawthorn Group is
responsible for the development of the Mt. Dora Ridge's distinctive landscape. A paleo-sand
dune field occurs in the eastern portion of the ridge in eastern Marion and northern Lake counties
(OFMS 105, Plate 1). The area, known as the Big Scrub in the Ocala National Forest, is highly
karstified. Tertiary/Quaternary dune sediments (TQd) overlie the Cypresshead Formation on part
of the Mt. Dora Ridge. Elsewhere, the Cypresshead Formation lies on the Hawthorn Group.

Ocklawaha River Valley

The Ocklawaha River Valley is a narrow valley extending from near the Lake-Marion
County line northward to the Marion-Putnam County line. To the south, the valley abuts the
Tavares Lakes Region. To the north, it merges with the St. Johns River Offset. The headwaters
of the Ocklawaha River occur in Lake Griffin, in the Tavares Lakes Region, a broader and more
karstic portion of the Central Lakes Region. As it enters the Ocklawaha River Valley, the river
becomes confined to a narrow valley bounded by the Ocala Karst Hills and the Fort McCoy Plain






OPEN-FILE REPORT 101


on the west and the Mt. Dora Ridge on the east (OFMS 105; Plate 3, Figure 3). The terrane is
underlain by Cypresshead Formation, Hawthorn Group sediments and undifferentiated
Quaternary sediments. Elevations of the valley within the study area range from 40 feet (12.2
meters) to 70 feet (21.3 meters) above MSL.

St. Johns River Offset

The St. Johns River flows northward from the headwaters in Palm Beach County,
flowing into the Atlantic Ocean in Duval County (OFMS 105; Plate 3, Figure 3). The upper and
lower St. Johns River valleys follow a pathway that is closer to the Atlantic coastline than the
middle reach of the river between Sanford and Palatka. At the approximate latitude of Sanford,
Seminole County, the river jogs westward then northward in a narrow valley bounded in the
study area by the Mt. Dora Ridge on the west and the DeLand Ridge and the Crescent City Ridge
on the east. White (1970) named and described this as the St. Johns River Offset. Elevations in
the terrane vary from less than 5 feet (1.5 meters) to 75 feet (22.9 meters) above MSL. White
believed that this portion of the St. Johns River's course was first developed in the Pliocene or
early Pleistocene by dissolution of the underlying Eocene carbonate sediments. Pirkle (1971)
suggested that the dissolution along the west-to-east trend resulted from faulting and fracturing
of the Eocene rocks. White (1970) believed that a complex geomorphic history was necessary to
force the St. Johns River out of its coast-parallel course and into a more inland, older valley.
Within the offset there are varying thicknesses of undifferentiated Quaternary sediments lying on
the Ocala Limestone.

Ocala Karst District

The Ocala Karst District encompasses a broad area extending from Wakulla County in the
panhandle to Hillsborough and Pinellas counties in west-central peninsular Florida (OFMS 105,
Plate 3, Figure 2). Carbonate sediments ranging from the Middle Eocene Avon Park Formation to
the Oligocene-Miocene Tampa Member of the Arcadia Formation (Hawthorn Group) lie near the
land surface. Dissolution of these sediments has created distinct landforms that characterize the
district, including caves, caverns numerous springs, sinking (swallets) and resurgent streams. The
Ocala Karst District merges with the Central Lakes District with which it shares a karstic influence
(OFMS 105; Plate 3, Figure 2). The southern terminus of the district occurs where the impermeable
Hawthorn Group sediments retard the development of karst features in the Sarasota River District
and streams and rivers become more common.
Elevations within the district range from sea level to over 300 feet (91.4 meters) above
MSL. Only a small portion of the District occurs along the southwest comer of the mapped area
(OFMS 105; Plate 3, Figure 3). Elevations range from 40 feet (12.2 meters) to 180 feet (54.9
meters) above MSL in the southeastern portion of the Ocala Karst Hills within the mapped area.
The topography over much of the district is gently rolling with only minor relief.
Sinclair and Stewart (1985) delineated zones of similar karst development in Florida based
on the thickness and type of sediment cover and on the sinkhole types. Carbonate sediments of the
Ocala Karst District are overlain by siliciclastics of varying thickness ranging from a few feet (one
meter) to as much as 200 feet (61 meters) over carbonate sediments. Cover subsidence and cover
collapse sinkholes are the dominant sinkhole type in the district. Rock collapse sinks occur but are
uncommon.






FLORIDA GEOLOGICAL SURVEY


Regional geomorphic terranes are recognized within the Ocala Karst District based on
elevation, abundance of karst features, drainage, and relief. One geomorphic terrane, the Ocala
Karst Hills, is recognized within the Ocala Karst District within the mapped area based on elevation,
abundance of karst features, drainage, and relief (OFMS 105, Plate 3, Figures 1 and 3).

Ocala Karst Hills

The Ocala Karst Hills terrane occurs from north-central Marion County southward to
northeastern Sumter County (OFMS 105, Plate 3, Figure 3). Statewide, elevations in the terrane
area range from 20 feet (6.1 meters) to 195 feet (59.4 meters) above MSL. Elevations of the terrane
within the mapped area range from 40 feet (12.2 meters) to 180 feet (54.9 meters) above MSL.
Several springs are present in the Ocala Karst Hills, including Silver Springs, which occurs
along the eastern edge of the terrane along the boundary with the Central Lakes District. Hawthorn
Group sediments are thin to absent in the terrane. Cypresshead Formation sediments overlie
Hawthorn Group in the area (Green, et al., 2009a). There is a small area in the Ocala Karst Hills
along the southwestern boundary of the mapped area which has undifferentiated Quaternary
sediments at the surface (OFMS 105, Plate 1).

LITHOSTRATIGRAPHIC UNITS

Tertiary System

Eocene Series

Avon Park Formation

The Middle Eocene Avon Park Formation (Tap), first described by Applin and Applin
(1944), is entirely a subsurface unit within the USGS Daytona Beach 30 x 60 minute quadrangle.
It was encountered in many of the wells utilized for this study and efforts were made to include it
in the geologic cross sections where suitable well coverage existed (see OFMS 105, Plate 2).
Lithology of the Avon Park Formation can vary between limestone and dolostone. The
limestones consist of cream to light brown to tan, poorly- to well-indurated, variably
fossiliferous grainstone and wackestone, with rare mudstone. The limestones are often
interbedded with tan to brown, very poorly- to well-indurated, very fine to medium crystalline,
fossiliferous (molds and casts), vuggy dolostones. Minor clay beds and organic-rich laminations
may occur, especially at or near the top of the unit. Accessory minerals include chert, pyrite,
celestine, gypsum and quartz (some as doubly-terminated euhedral crystals "floating" in vugs).
Fossils present in the unit include molluscs, foraminifera (Spirolina sp., Lituonella
floridana, Bolivina spp., Cushmania [Dictyoconus] americana), Cribrobulimina cushmani, and
Fabiana cubensis, echinoids (Neolaganum [Peronella] dalli), algae and carbonized plant
remains. Porosity in the Avon Park Formation is generally intergranular in the limestone section.
Fracture porosity occurs in the more densely recrystallized dolostone and intercrystalline
porosity is characteristic of sucrosic textures. Pinpoint vugs and fossil molds are present to a
lesser extent.
Distinction between the Middle Eocene Avon Park Formation and the unconformably
overlying unit, the Upper Eocene Ocala Limestone, can at times be difficult in the study area,
particularly in the vicinity of the Sanford High (where the Ocala Limestone is often thin to






OPEN-FILE REPORT 101


missing). Dolomitization of the Avon Park Formation and common recrystallization of the
lowermost Ocala Limestone has significantly altered the original rock lithology and fabric. Fossil
indicators are only somewhat helpful because the latest deposits of the Avon Park Formation and
the earliest deposits of the Ocala Limestone are both bank assemblages, consistent with
deposition in a shallow-water limestone bank or plateau, not unlike the present day Bahama
Banks (Bryan, 2004).
The top of the Avon Park ranges from approximately 5 feet (1.5 meters) below MSL in
W-5611 (OFMS 105; Plate 2, cross-section D-D') to approximately 170 feet (51.8 meters) below
MSL in W-18815 (OFMS 105; Plate 2, cross-sections E-E'). Due to graphical space constraints,
as well as limited coverage of deeper wells, the total thickness of the Avon Park Formation was
not investigated in this study. The Avon Park Formation forms part of the FAS (Southeastern
Geological Society Ad Hoc Committee on Florida Hydrostratigraphic Unit Definition, 1986).

Ocala Limestone

The Upper Eocene Ocala Limestone (To), first described by Dall and Harris (1892), is a
biogenic marine limestone comprised largely of foraminifera, molluscs, echinoids and
bryozoans. The Ocala Limestone, which sits unconformably on the Avon Park Formation
throughout most of the study area, is thin to absent in the vicinity of the Sanford High.
Based on lithologic differences, the Ocala Limestone can be informally subdivided into
an upper and lower unit (Scott, 1991). This subdivision, while often apparent in cores and
quarries, is not readily apparent in cuttings. As a consequence of this, the geologic cross-
sections do not break out the upper and lower Ocala Limestone. The upper unit is typically a
white to cream, fine- to coarse-grained, poorly to well-indurated, moderately to well-sorted, very
fossiliferous limestone (wackestone, packstone, and grainstone). Fossils commonly include
foraminifera, bryozoans, molluscs, and a rich diversity of echinoids. The lower unit is typically a
white to cream, fine- to medium-grained, poorly to moderately indurated, moderately- to well-
sorted limestone (grainstone to packstone). Fossils include foraminifera (Lepidocyclina ocalana,
Amphistegina pinarensis, Nummulites [Camerina] vanderstoki, Nummulites [Operculinoides]
ocalana), bryozoans, algae, molluscs, echinoids, and crustaceans.
The Ocala Limestone occurs throughout most of the study area (except where missing on
the Sanford High) and is near the surface along the northwestern portion of the map area (OFMS
105, Plate 2). The top of the Ocala Limestone ranges from 23 feet (7 meters) above MSL in W-
10360, (OFMS 105; Plate 2, cross-section B-B') to 97 feet (29.6 meters) below MSL in W-4065
and W15133 (OFMS 105; Plate 2, cross-section A-A'). Approximately 60 percent of the wells
utilized for geologic cross-sections penetrate the entire thickness of the Ocala Limestone. In
these wells, the thickness of the Ocala Limestone ranges from 135 feet (41 meters) in W-11634
(OFMS 105; Plate 2, cross-section B-B') to 5 feet (1.5 meters) in W-15352 (OFMS 105; Plate 2,
cross-section D-D'). The Ocala Limestone is generally thickest in the western portion of the
study area away from the Sanford High. The Ocala Limestone forms part of the FAS
(Southeastern Geological Society Ad Hoc Committee on Florida Hydrostratigraphic Unit
Definition, 1986).






FLORIDA GEOLOGICAL SURVEY


Miocene Series

Hawthorn Group

Sediments of the Miocene Hawthorn Group are thought to have been deposited over the
Peninsular Arch throughout much of the study area, but erosion and karstification have removed
these sediments from the crest of the Ocala Platform (Cooke, 1945; Espenshade and Spencer,
1963; Scott, 1983). The unit is also missing in the vicinity of the Sanford High (Scott, 1988).
Hawthorn Group sediments within the study area consist of phosphatic siliciclastics (sands, silts
and clays) and carbonates (dolostone with minor limestone). Fossils in the Hawthorn Group are
sparse but may include vertebrates, corals, and molluscs. Benthic foraminifera characteristic of
the Hawthorn Group include Archaias spp. and Sorites sp. Williams et al. (1977) report that the
most commonly found fossils are oysters and coral heads.
Within the mapped area, the Hawthorn Group is composed of the Penney Farms
Formation (Thpf), the Marks Head Formation (Thmh) and the Coosawhatchie Formation (Thc;
OFMS 105; Plate 2, Figure 2). While these formations can be identified and delineated in cores,
they are often not readily differentiated in cuttings, particularly where cavings from above cause
mixing of the sediments during drilling. In these instances, they are referred to as
undifferentiated Hawthorn Group (Th) on the cross-sections. In instances where they can
reliably be differentiated, the formations are shown on the cross-sections (OFMS 105; Plate 2,
cross-sections B-B' and C-C'). Unit descriptions for the Hawthorn Group listed below are
summaries and the reader is referred to Scott (1988) for a more complete discussion of
lithologies, variability and relationships of these lithologically complex formations. Hawthorn
Group sediments are unconformably overlain by Tertiary/Quaternary dune sediments,
Cypresshead Formation (TQc) and undifferentiated Quaternary sediments (Qu).
In the mapped area, Hawthorn Group sediments occur primarily west of Lake George and
the St. Johns River (OFMS 105, Plate 1). The top of the Hawthorn Group ranges between 70
feet (21.3 meters) above MSL in W-3886 (OFMS 105; Plate 2, cross-section B-B') to 56 feet (17
meters) below MSL in W-19453 (OFMS 105; Plate 2, cross-section C-C'). The Hawthorn Group
sediments range in thickness from 78 feet (23.8 meters) in well W-19451 to 10 feet (3 meters) in
well W-10360 (OFMS 105; Plate 2, cross-section B-B'). Sediments of the Hawthorn Group form
the Intermediate aquifer system/Intermediate confining unit (IAS/ICU; Southeastern Geological
Society Ad Hoc Committee on Florida Hydrostratigraphic Unit Definition, 1986).

Penney Farms Formation

The Penney Farms Formation (Thpf) consists of variable admixtures of dolostone, quartz
sand, phosphatic sand and clay. The sand content is variable and at times the unit becomes a
dolomitic sand. Phosphatic sand is common and may be present in amounts exceeding 25 percent
with an average of 5 to 10 percent (Scott, 1988). Clay percentages are generally minor (less than
5 percent) and often increase towards the top of the unit in the dolostones. The dolostones are
medium-gray to pale-yellowish brown and are generally moderately- to well-indurated. Mollusc
molds are common in the dolostones. Intraclasts are common in the hard, finer-grained
dolostones in the lower portion of the unit. These intraclasts are composed of dolomite similar to
the rest of the unit, but they often have rims of phosphate replacement along the edges of the
clasts (see OFMS 105; Plate 2, Figure 2, Photo 2). Limestone, which occurs sporadically in the
lower portion of the unit, is generally dolomitic, phosphatic, and quartz sandy. The Penney






OPEN-FILE REPORT 101


Farms Formation unconformably overlies the Ocala Limestone within the mapped area. Where
present in the mapped area, it is overlain unconformably by the Marks Head Formation
(Hawthorn Group). The base of the Marks Head Formation is placed at the contact between the
darker-colored sands and clays of the upper Penney Farms and the generally lighter-colored
interbedded sands, clays, and dolostone of the Marks Head Formation (OFMS 105; Plate 2,
cross-sections B-B' and C-C').

Marks Head Formation

The Marks Head Formation (Thmh) consists of interbedded sands, clays and dolostones.
Limestone, while uncommon, does occur within the unit (Scott, 1988). Dolostones are generally
quartz sandy, phosphatic and clayey. Colors of the dolostones range from yellowish-gray to olive
gray. Induration, which varies inversely with the clay content, ranges from poorlyconsolidated to
well indurated. Phosphate content typically ranges up to five percent but may occasionally be
significantly higher. Quartz sand content ranges from five percent to greater than 50 percent. The
unit is overlain unconformably by the Coosawhatchie Formation (Hawthorn Group), although
this unconformity is often not readily apparent. In general, the contact between the
Coosawhatchie and Marks Head formations is placed at the top of the first hard carbonate bed or
light-colored clay unit below the darker-colored, clayey, dolomitic quartz sands and dolostones
of the basal Coosawhatchie Formation (Scott, 1988).

Coosawhatchie Formation

The Miocene Coosawhatchie Formation (Thc) consists of quartz sands, dolostones and
clays. The unit ranges in color from greenish-gray and light gray to olive gray. The most
common lithology in the upper section of the unit is characteristically a sandy to very sandy
dolostone which may be interbedded with quartz sands and clays (Scott, 1988). Quartz sands and
clays dominate and dolostones become subordinate in the lower portion of the section. The
quartz sands are fine- to medium-grained, generally phosphatic, clayey and dolomitic. In many
instances, the sands grade into dolostones and clays. Clay content is variable and may range from
five to more than 30 percent (Scott, 1988). Phosphate content is highly variable, ranging from a
trace to more than 20 percent. Coarse phosphate sands and pebbles are present but not common
in the unit. The unit is unconformably overlain by the Pliocene/Pleistocene Cypresshead
Formation (TQc) in the vicinity of the Mt. Dora Ridge (OFMS 105, Plate 2, cross-sections B-B'
and C-C').

Hawthorn Group (Undifferentiated)

In the areas between the Sanford High and the Peninsular Arch, sediments of the
Coosawhatchie, Marks Head and Penney Farms formations often become difficult to break out
lithologically. In these areas, sediments of the Hawthorn Group are mapped as Hawthorn Group,
undifferentiated (Th; Scott, 1988).
Where exposed west of the mapped area, the undifferentiated Hawthorn Group is light
olive gray and blue gray in unweathered sections and reddish-brown to reddish-gray in
weathered sections (Green et al., 2009a). It consists of poorly- to moderately-consolidated,






FLORIDA GEOLOGICAL SURVEY


clayey sands to silty clays and relatively pure clays with little-to-no phosphate due to leaching
and transport (Scott, 2001). It is typically deeply weathered.
Where present, the undifferentiated Hawthorn Group unconformably overlies the Ocala
Limestone (Scott et al., 2001). It is unconformably overlain by the Cypresshead Formation (TQc)
and undifferentiated Quaternary and Holocene sediments (OFMS 105, Plate 2).
Due to the karstic nature of the Mt. Dora Ridge, elevations of the Hawthorn Group are
highly variable. Within the study area, the top of the unit may exceed 70 feet (21.3 meters) above
MSL as in well W-3886 (OFMS 105; Plate 2, cross-section B-B') or be at a depth of more than
55 feet (16.8 meters) below MSL (OFMS 105; Plate 2, cross-section C-C', W-19453). Along the
flanks of the ridge, thin beds of the undifferentiated Hawthorn Group were penetrated in various
wells (OFMS 105, Plate 2). In these, the top of the undifferentiated Hawthorn Group ranges from
33 feet (10 meters) above MSL in W-10360 (OFMS 105; Plate 2, cross-section B-B') to 34 feet
(10.4 meters) below MSL well W-8415 (OFMS 105; Plate 2, cross-section A-A'). Thickness of
the undifferentiated Hawthorn Group varies between 10 to 45 feet (3 to 13.7 meters).
Undifferentiated Hawthorn Group sediments are often clayey sands and only rarely consist of
relatively pure clays. The Hawthorn Group generally has low permeability and forms part of the
IAS/ICU (Southeastern Geological Society Ad Hoc Committee on Florida Hydrostratigraphic
Unit Definition, 1986).

Tertiary/Quaternary Systems

Pliocene/Pleistocene Series

Cypresshead Formation

The Pliocene/Pleistocene Cypresshead Formation (TQc), named by Huddlestun (1988), is
a mottled reddish-brown to reddish-orange to white, unconsolidated to poorly consolidated, fine-
to very coarse-grained, variably clayey to clean quartz sand. Cross-bedded sands are common
within this formation. Discoid quartzite pebbles, mica, and ghosts of nearshore marine molluscs
are often present. The Cypresshead Formation is present throughout much of the study area and
forms the core of the various ridges present in the region (see geomorphology section for more
discussion). East of the St. Johns River, it typically becomes a more weathered, finer-grained,
well-sorted sand and silt. In cores, the unit is often characterized by beds of fine grained, well
sorted sand with thin layers of clay dispersed through the sand.
Elevations range from near sea level to over 180 feet (54.9 meters) above MSL in the
mapped area. The Cypresshead Formation thickness ranges between 90 feet to 35 feet (27.4 to
10.7 meters) in study area wells.
These sediments sit unconformably on the undifferentiated Hawthorn Group (Th) or
Coosawhatchie Formation (Hawthorn Group; Thc) west of the St. Johns River and
undifferentiated Pliocene/Pleistocene shelly sediments (TQsu) in the eastern portion of the
mapped area (OFMS 105; Plate 2). Permeable sediments of the Cypresshead Formation form
part of the surficial aquifer system (SAS; Southeastern Geological Society Ad Hoc Committee
on Florida Hydrostratigraphic Unit Definition, 1986).






OPEN-FILE REPORT 101


Pliocene/Pleistocene Shelly Sediments

A sequence of undifferentiated Pliocene/Pleistocene shelly sediments lies east of the St.
Johns River and occupies the section where the Hawthorn Group is missing around the Sanford
High. Huddlestun (1988) named this unit the Nashua Formation. Much of the evidence listed by
Huddlestun (1988) was based on biostratigraphic correlation and not lithologic distinction.
Efforts were made by the authors to locate the type section of the Nashua Formation, as defined
by Huddlestun (1988), to no avail. Since we did not have adequate core control and could not
locate the type section, these authors have decided to utilize the convention of the Scott, et al.
(2001) and map these sediments as undifferentiated Pliocene/Pleistocene shelly sediments
(TQsu). The unit sits unconformably on the Ocala Limestone or, in the vicinity of the Sanford
High, the Avon Park Formation (OFMS 105; Plate 2, cross-sections A-A', B-B' and D-D').
Huddlestun (1988) indicated that the unit grades laterally into the Cypresshead Formation (TQc)
in the vicinity of the Trail Ridge (northwest of the mapped area). Evidence from this study,
however, indicates that the unit is, at least in part, older than the Cypresshead Formation. This
may be a result of prograding of deltaic Cypresshead Formation sediments over TQsu marine
sediments during changes in sea level. Work currently underway at the Florida Museum of
Natural History indicates that some of these shelly sands just north of the study area are Pliocene
(Roger Portell, personal communication). These undifferentiated shelly sands are overlain by the
Cypresshead Formation in the Crescent City and DeLand ridges (OFMS 105, Plate 2, cross-
section D-D'). Elsewhere, the unit is unconformably overlain by undifferentiated Quaternary
sediments, Quaternary beach ridge and dune sediments (Qbd) or the Anastasia Formation (Qa).
Undifferentiated Pliocene/Pleistocene shelly sediments (TQsu) typically consist of fine-
to-medium quartz sand with variable amounts of calcilutite, shell and clay. Shells may vary from
whole to fragments and may occasionally become the dominant lithology. Other accessory
minerals may include calcite, aragonite, clay, mica, heavy minerals and minor phosphate. Colors
range from light gray to light olive gray.
The top of the undifferentiated Pliocene/Pleistocene shelly sediments ranges from 50 feet
(15.2 meters) above MSL in W-5611, (OFMS 105; Plate 2, cross-section D-D') to 45 feet (13.7
meters) below MSL in W-15667 (OFMS 105; Plate 2, cross-section E-E'). The thickness of the
undifferentiated Pliocene/Pleistocene shelly sediments in the cross-section wells varies from 95
feet (28.9 meters) in W-15133 (OFMS 105; Plate 2, cross-section A-A') to 15 feet (4.6 meters) in
W-18282 (OFMS 105; Plate 2, cross-section A-A'). Permeable sediments of the undifferentiated
Pliocene/Pleistocene shelly sediments form part of the SAS (Southeastern Geological Society Ad
Hoc Committee on Florida Hydrostratigraphic Unit Definition, 1986).

Tertiary/Quaternary Dunes

Tertiary/Quaternary dunes (TQd), while not a formally recognized lithostratigraphic unit,
are mapped following the convention of Scott et al. (2001) in order to facilitate a better
understanding of Florida's geology. Where LiDAR is available these dunes are readily
differentiated from other units by their distinct topographic expression. These dune sediments are
fine-to-medium quartz sand with varying amounts of disseminated organic matter. They are
generally found at elevations above 100 feet (30.5 meters) MSL, although there are areas along
the flanks of the Mt. Dora Ridge where elevations of these dune sands can be lower. Sands
forming these dunes are thought to be derived from re-working of sediments from the






FLORIDA GEOLOGICAL SURVEY


Cypresshead Formation (TQc) and undifferentiated Quaternary sediments (Qu). There are large
portions of the Mt. Dora Ridge in the Ocala National Forest and sections of the DeLand Ridge
which have Tertiary/Quaternary dune sediments mapped (OFMS 105, Plate 1). These sediments
are considered part of the SAS (Southeastern Geological Society Ad Hoc Committee on Florida
Hydrostratigraphic Unit Definition, 1986).

Pleistocene to Holocene Series

Anastasia Formation

The Anastasia Formation (Qa) is present within the Atlantic Coastal Complex in a narrow
band along the eastern edge of the study area. The formation, named by Sellards (1912), is
composed of interbedded coquinoid limestone and quartz sands. It typically occurs as an
orangish-brown, unindurated to moderately indurated coquina consisting of whole and broken
mollusc shells in a quartz sand matrix. The coquina is commonly cemented by sparry calcite.
The sands occur as light gray to tan and orangish-brown, unconsolidated to moderately
indurated, unfossiliferous to very fossiliferous beds. The unit sits unconformably on
undifferentiated Pliocene/Pleistocene shelly sediments (TQsu; OFMS 105, Plate 2, cross-section
E-E'). The top of the Anastasia Formation ranges from 5 feet (1.5 meters) above MSL in wells
W-3473 and W-11047 (OFMS 105; Plate 2, cross-section E-E'), to 12 feet (3.7 meters) below
MSL in W-3976 (OFMS 105; Plate 2, cross-section A-A'). The thickness of the Anastasia
Formation in the cross-section wells varies from 45 feet (13.7 meters) in W-15667 to 10 feet (3
meters) in W-18815 (OFMS 105; Plate 2, cross-section E-E'). This formation is considered part
of the SAS (Southeastern Geological Society Ad Hoc Committee on Florida Hydrostratigraphic
Unit Definition, 1986).

Undifferentiated Quaternary Sediments

Undifferentiated Quaternary sediments (Qu) in the study area lie unconformably on the
Hawthorn Group, undifferentiated Pliocene/Pleistocene shelly sediments or Cypresshead
Formation (OFMS 105, Plate 2, cross-sections). The undifferentiated Quaternary sediments
present in the mapped area may be highly variable in thickness.
Generally, these undifferentiated Quaternary sediments consist of white to gray to orange
to blue-green, fine- to coarse-grained, clean to clayey unfossiliferous sands, sandy clays and
clays with variable admixtures of organic. The undifferentiated Quaternary sediments form part
of the SAS (Southeastern Geological Society Ad Hoc Committee on Florida Hydrostratigraphic
Unit Definition, 1986).

Quaternary Beach Ridge and Dune

Quaternary beach ridge and dune sediments (Qbd) are a subdivision of the
undifferentiated Quaternary sediments that are noted on the basis of surficial expression of relict
beach ridges and dunes. While not a formally recognized lithostratigraphic unit, it is mapped
following the convention of Scott et al., (2001) in order to facilitate a better understanding of
Florida's geology. This unit unconformably overlies undifferentiated Pliocene/Pleistocene shelly






OPEN-FILE REPORT 101


sediments (TQsu), or the Anastasia Formation (Qa) in the eastern part of the study area (OFMS
105; Plates 1 and 2).
Beach ridge and dune sediments are dominantly siliciclastic sands and are unconsolidated
to poorly consolidated. Organics typically occur as disseminated organic matrix, roots and plant
debris, carbonized remains or charcoal. The unit is considered part of the SAS (Southeastern
Geological Society Ad Hoc Committee on Florida Hydrostratigraphic Unit Definition, 1986).

Holocene Sediments

Sediments mapped as Holocene (Qh) may include quartz sands, marls, organic, and
minor carbonate sands and mud. They may also include fresh-water molluscs. Within the study
area, they occur as floodplain deposits in the vicinity of Lake George, the St. Johns River and the
Ocklawaha River. These sediments are considered part of the SAS (Southeastern Geological
Society Ad Hoc Committee on Florida Hydrostratigraphic Unit Definition, 1986).

HYDROGEOLOGY

Hydrostratigraphic units within the map area, in ascending order, consist of the Floridan
aquifer system (FAS), the Intermediate aquifer system/Intermediate confining unit (IAS/ICU),
and the Surficial aquifer system (SAS; Southeastern Geological Society Ad Hoc Committee on
Florida Hydrostratigraphic Unit Definition, 1986). The FAS, the primary source for springs and
drinking water in the region, is generally comprised of carbonate units of the Avon Park
Formation and the Ocala Limestone. The sands, silts, clays and carbonates of the Hawthorn
Group comprise the IAS/ICU. The IAS/ICU is highly localized and laterally discontinuous in
the study area. The SAS is comprised of the Cypresshead Formation, undifferentiated
Pliocene/Pleistocene shelly sediments (TQsu), Tertiary/Quaternary dune sediments (TQd),
undifferentiated Quaternary sediments (Qu), beach ridge and dune sediments (Qbd), and
Holocene sediments (Qh).
Where clayey siliciclastic sediments of the Hawthorn Group and younger units are thick
and continuous, they provide confinement for the FAS, but where the clayey siliciclastic
sediments of the Hawthorn Group and younger units are thin, missing or lack significant clay
component, karst features often occur. Several of these are found in the Crescent City and
DeLand ridges.

GEOPHYSICAL LOGGING

As part of this project, the St. Johns River Water Management District (SJRWMD)
conducted geophysical logging on new wells drilled in the study area by the Florida Geological
Survey. Boreholes were logged with a variety of geophysical tools, including Gamma (natural
gamma log), Caliper, and Induction logs (Fluid Resistivity and Fluid Conductivity). The
geophysical log of particular interest in this study was the gamma log for its usefulness in
differentiating the various lithostratigraphic units by recording the naturally occurring gamma-
ray activity in the lithology of the borehole wall.
By comparing gamma-ray activity between lithostratigraphic units it is often possible to
differentiate them. This log is particularly useful for differentiating between Hawthorn Group
units and subjacent and superjacent formations. Kwader (1982) and Scott (1988) discuss the






FLORIDA GEOLOGICAL SURVEY


gamma-ray response from clay minerals and phosphate typical to the formations in the Hawthorn
Group. Development of high gamma activity occurs when minerals incorporate high
percentages of potassium, uranium or thorium in their lattice structures. Potassium-rich sources
include potassium feldspar, mica, and illitic clay. Uranium and thorium tend to be found in
phosphorite, apatite, organic material and dolomite.


GAMMA LOG


) Tertiary/Quaternary
Dune Sediments


Coosawhatchie Formation (Hawthorn Group)


Marks Head Formation (Hawthorn Group)


DEPTH


Figure 6. Gamma Log of W-19451 (see OFMS
105, plate 2, B-B')


O CPS


Gamma-ray intensity units were
measured in counts per second (CPS). In
Figure 6, gamma-ray intensity units are
shown on the log horizontal axis in CPS
for W-19451 (see OFMS 105, Plate 2,
cross-section B-B'). Carbonates of the
Ocala Limestone and Avon Park
Formation have the lowest intensity
gamma peaks in contrast to the high
intensity radioactivity of the Hawthorn
Group. Formations above the Hawthorn
Group, such as the Cypresshead
Formation and Tertiary-Quaternary dune
sediments (TQd), typically have much
lower intensity signatures. In the study
area, elevated radioactivity primarily
results from the inclusion of phosphate
grains. Medium intensity gamma-ray
signatures are from moderately
radioactive clay-minerals and from
organic material or peat (Davis et. al.,
2001).

Stratigraphy and Gamma-Ray Log
Interpretation

Avon Park Formation

Logs from the Avon Park
Formation typically show a combination
of low gamma-ray intensity dolostone
with distinct beds of relatively higher
gamma-ray intensity lignite or organic
layers. The top of the Avon Park
Formation characteristically ranges from a
yellow-gray dolomitic wackestone to a
yellow-brown recrystallized dolostone.
Below this initial lithology, but usually at
or near the top of the unit, there can be
variable amounts of black to dark brown,
finely particulate to fibrous, partially
decomposed organic material or lignite.






OPEN-FILE REPORT 101


The organic matter can occur as finely disseminated particles, sand to pebble sized blebs,
identifiable leaf or sea-grass fossils, laminations or as discrete beds. One such bed of organic-
rich material can be seen in Figure 6, the top of the Avon Park Formation at approximately 295
feet (89.9 meters) below land surface (BLS).

Ocala Limestone

In contrast to the higher intensity gamma-ray signature of the Hawthorn Group, the Ocala
Limestone is easily identified on the gamma-ray log. This unit characteristically produces the
lowest gamma-ray intensity in the Eocene stratigraphic sequence and can be used as a low
baseline for relative gamma-ray intensity (Davis et. al., 2001).
In general, the Ocala Limestone has lower gamma-ray intensity than the underlying Avon
Park Formation. In the study area, however, dolomitization of the Avon Park Formation and
recrystallization of the lowermost Ocala Limestone has significantly altered the original rock
lithology and fabric making the distinction of the gamma-ray signatures between these units
more difficult. The presence of organic when at or near the top of Avon Park Formation (e.g.,
Figure 6) can assist in determining the contact between these two formations. One such organic-
rich zone occurs at 295 feet (89.9 meters) BLS.

Hawthorn Group

The Hawthorn Group consists of a complex sequence of siliciclastics and carbonates with
varying percentages of phosphate minerals. The resulting gamma-ray peaks are, in general,
significantly higher than those of the formations above and below the Hawthorn Group which
makes this unit easily discernible on geophysical logs (Figure 6).
The Hawthorn Group in the western portion of the study area consists of the Penney
Farms, Marks Head and Coosawhatchie formations. The gamma-ray logs from the cores drilled
for this study show a pattern of three generalized zones corresponding with these formations.
However, the pattern shows a variation in the intensities and thickness of peak groups dependent
on the lithologic variation of the sample. For example, in W-19451 (OFMS 105; Plate 2, cross-
section C-C') the higher gamma-ray intensity zones at approximately 138-158 feet (42-48.2
meters) BLS correlate with the Coosawhatchie Formation. The Coosawhatchie Formation in this
well consists primarily of siliciclastics with varying amounts of dolomitic clay and fine to pebble
sized phosphate ranging in content between three and fifteen percent. The second zone is a low
intensity gamma-ray zone of the Marks Head Formation (between 158-167 feet [48.2-50.9
meters] BLS) consisting of a well-indurated, light gray recrystallized dolosilt with one to three
percent fine-to-medium phosphate. The third zone correlates with the Penney Farms Formation
showing a drop in the gamma-ray intensity at approximately 167 feet (50.9 meters) BLS at an
unconformity, followed by a significant peak at about 168 feet (51.2 meters) BLS where the
lithology is a phosphatic, clayey sand with burrows and intraclasts.
The Penney Farms Formation in this core is highly variable in lithology and phosphate
content as reflected in the gamma-ray log. The Penney Farms Formation unconformably
overlies the Ocala Limestone. At this contact, the gamma-ray log intensity drops significantly
and the delineation of these two formations is readily apparent (Figure 6).






FLORIDA GEOLOGICAL SURVEY


Pliocene/Pleistocene shelly sediments

In the study area east of the St. Johns River, undifferentiated Pliocene/Pleistocene shelly
sediments (TQsu) lie unconformably over the Hawthorn Group, and below the undifferentiated
Quaternary sediments or Cypresshead Formation (OFMS 105, Plate 2). Undifferentiated
Pliocene/Pleistocene shelly sediments present in the mapped area may be highly variable in
thickness and typically consist of fine to medium quartz sand with variable amounts of
calcilutite, shell, phosphate and clay. Other accessory minerals may include calcite, aragonite,
clay, mica, and heavy minerals. The presence of phosphate and heavy minerals can cause spikes
in the gamma-ray log making this unit readily distinguishable from the overlying Cypresshead
Formation or undifferentiated Quaternary sediments.

Cypresshead Formation and Tertiary/Quaternary dune sediments

The Cypresshead Formation (TQc) is typically composed of variably clayey quartz sand,
silt and gravel characteristic of a fluvio-deltaic deposit. The sediments of the
Tertiary/Quaternary dune sediments (TQd) are fine to medium quartz sand with varying amounts
of disseminated organic matter. Often, the Cypresshead Formation cannot be readily
distinguished from the overlying TQd by the gamma-ray log due to their similar lithologies.
Because these units lack phosphate, they are easily distinguishable from the underlying
Hawthorn Group (Figure 6).


DERIVATIVE PRODUCTS

Several derivative products will come from this project. During the mapping project,
data from over 400 wells with samples were analyzed. Formation picks, made on all available
wells with cores and cuttings samples, allow creation of a structure contour map of the top of the
FAS, along with the construction of structure contour and isopach maps of the IAS/ICU in the
area. Additional derivative data anticipated to come from this mapping effort include aquifer
vulnerability assessment maps. Data derived from prior STATEMAP products have often been
used to augment other Florida Geological Survey and Florida aquifer vulnerability assessment
(FAVA) projects in the state (Arthur et al., 2007; Baker et al., 2007).






OPEN-FILE REPORT 101


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FLORIDA GEOLOGICAL SURVEY


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FLORIDA GEOLOGICAL SURVEY


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ACKNOWLEDGEMENTS

The authors extend many thanks to the personnel that assisted with access to land
holdings: Donna Watkins with the Florida Department of Environmental Protection's Division
of Recreation and Parks expedited the permit process for rock sample collection in Florida State
Parks. Steven R. Miller with the St. Johns River Water Management's Bureau of Land
Management was instrumental in granting the Special Use Authorization that allowed the FGS
access for field reconnaissance and drilling on SJRWMD properties. SJRWMD Land Managers
Crystal Morris, Stuart Jones, and R.H. Davis provided us the necessary information and
resources for accessing their properties. Tim Telfer and Michael Lagasse, from Flagler County
Land Management helped with access and a guided tour of the Haw Creek Conservation Area.
Robert Macon, Tonnee Davis and District Ranger Mike Herrin helped obtain a Special Use
Permit required for drilling and sample collecting in the Ocala National Forest.
We would also bestow a special thanks to Jeffery B. Davis with the SJRWMD Bureau of
Groundwater Sciences for sharing his knowledge and experience on the overall geology and
geophysical data within the study area as well as sponsoring the 2012 SMAC meeting in Palatka
Florida. Jill Andrea, with the SJRWMD Division of Water Resources GeoSpatial Scientist,
provided the FGS STATEMAP program with valuable GIS data. LiDAR coverage provided by
Richard Helfst from Lake County GIS Services Division of Information Technology was
extremely valuable in developing our geology maps and our top of rock modeling. Discussions
with Roger Portell the Director of Invertebrate Paleontology at the Florida Museum of Natural
History, were helpful in establishing the age correlation of some of the Tertiary/Quaternary units
within the study area. The FGS STATEMAP staff would like to thank Mr. Johnny Arrigano,
owner of Arrow Materials and Excavating, for allowing us to sample his borrow pit.
Seth Bassett, Bob Cleveland, Levi Hannon, Lee Hartman, Jesse Hurd, David Paul, Eric
Thomas and Christopher Williams provided field support for drilling operations. Tyler Weinand
of the St. Johns River Water Management District provided geophysical logging for the new






FLORIDA GEOLOGICAL SURVEY


cores collected in the study area. Levi Hannon, Alan Baker and James Cichon worked to make
sure all wells were appropriately located using every piece of archived well location information
that could be found. Thank you to Frank Rupert, Jackie Lloyd, and Harley Means who reviewed,
discussed and edited the product. Tom Scott continues to be an asset to geologic mapping in
Florida and the ongoing work to revise the state's geomorphic map. This geologic map was
funded in part by the Office of the Florida Geological Survey of the Florida Department of
Environmental Protection and by the United States Geological Survey National Cooperative
Geologic Mapping Program under assistance award number G12AC20412 in Federal fiscal year
2012.








OPEN-FILE REPORT 101



APPENDIX A: FGS WELLS UTILIZED FOR STUDY

This table lists FGS wells within the boundaries of the USGS Daytona Beach 30 x 60 minute
quadrangle utilized for the top of rock model and/or geologic mapping. Due to graphical
constraints, not all wells will appear on Plate 1 of OFMS 105. The first 40 wells in the table were
utilized for geologic cross-sections and appear on Plates 1 and 2 of OFMS 105.


Map Well Data Sample Latitude Longitude 24K Quad Elevation Total
ID Label Source Type (ft) Depth (ft)
1 W-657 FGS Cuttings 29.057207 81.284507 DELAND 72 511
2 W-1118 FGS Cuttings 29.037454 81.166793 DAYTONA BEACH SW 40 5958
3 W-3473 FGS Cuttings 29.348867 -81.088452 ORMOND BEACH 10 147
4 W-3886 FGS Cuttings 29.061175 -81.633026 FARLES LAKE 112 114
5 W-3957 FGS Cuttings 29.328611 -81.771944 LAKE KERR 74 131
6 W-3976 FGS Cuttings 29.279701 -81.062553 ORMOND BEACH 8 207
7 W-4065 FGS Cuttings 29.33066 -81.329785 CODYS CORNER 13 188
8 W-4069 FGS Cuttings 29.442638 -81.538192 CRESCENT CITY 65 115
9 W-5039 FGS Cuttings 29.320232 -81.392224 SEVILLE 13 107
10 W-5573 FGS Cuttings 29.012656 -81.645593 FARLES LAKE 57 200
11 W-5611 FGS Cuttings 29.121674 -81.315836 DELAND 80 225
12 W-6136 FGS Cuttings 29.050833 -81.755278 LAKE MARY 144 240
13 W-6137 FGS Cuttings 29.2666 -81.030356 ORMOND BEACH 12 160
14 W-7842 FGS Cuttings 29.298333 -81.835277 LAKE KERR 90 280
15 W-8134 FGS Cuttings 29.035346 -81.289603 DELAND 86 390
16 W-8415 FGS Cuttings 29.322472 -81.966477 FORT MCCOY 66 145
17 W-10360 FGS Cuttings 29.025462 -81.962674 LAKE WEIR 98 520
18 W-10935 FGS Cuttings 29.036371 -81.465068 LAKE WOODRUFF 42 310
19 W-11047 FGS Cuttings 29.243591 -81.046165 DAYTONA BEACH 5 210
20 W-11634 FGS Cuttings 29.053629 -81.880195 LAKE WEIR 89 295
21 W-12371 FGS Cuttings 29.05537 -81.018042 SAMSULA 25 250
22 W-13594 FGS Cuttings 29.146102 -81.031728 DAYTONA BEACH 31 200
23 W-14318 FGS Core 29.384685 -81.512155 CRESCENT CITY 54 158
24 W-14752 FGS Core 29.211111 -81.728888 JUNIPER SPRINGS 68 93
25 W-15118 FGS Cuttings 29.274364 -81.09203 ORMOND BEACH 23 200
26 W-15133 FGS Cuttings 29.287264 -81.159063 FAVORETTA 23 205
27 W-15352 FGS Cuttings 29.136797 -81.334614 LAKE DIAS 64 240
28 W-15667 FGS Cuttings 29.433963 -81.114219 FLAGLER BEACH EAST 0 120
29 W-15729 FGS Cuttings 29.061527 -81.348229 DELAND 72 450
30 W-15921 FGS Cuttings 29.310377 -81.494339 SEVILLE 39 170
31 W-17567 FGS Cuttings 29.471388 -81.809999 LAKE DELANCY 81 200
32 W-17571 FGS Cuttings 29.142777 -81.704999 JUNIPER SPRINGS 118 71
33 W-18282 FGS Cuttings 29.321666 -81.539444 WELAKA SE 20 170
34 W-18815 FGS Core 29.200555 -81.039444 DAYTONA BEACH 6 1001
35 W-19022 FGS Cuttings 29.325832 -81.079722 ORMOND BEACH 6 86
36 W-19444 FGS Core 29.0335 -81.09509 SAMSULA 43 200
37 W-19448 FGS Core 29.227563 -81.362112 LAKE DIAS 28 200
38 W-19451 FGS Core 29.049766 -81.675616 FARLES LAKE 178 303
39 W-19452 FGS Core 29.406833 -81.806416 LAKE DELANCY 123 318
40 W-19453 FGS Core 29.254066 -81.7698 LAKE KERR 114 273
41 W-153 FGS Cuttings 29.030308 -81.911444 LAKE WEIR 58 350
42 W-177 FGS Cuttings 29.485565 -82.016519 CITRA 69 95
43 W-181 FGS Cuttings 29.375246 -81.899592 EUREKA DAM 21 65
44 W-183 FGS Cuttings 29.23577 -81.964577 LYNNE 69 133
45 W-194 FGS Cuttings 29.485162 -81.186782 FLAGLER BEACH WEST 20 70
46 W-195 FGS Cuttings 29.459726 -81.262505 BUNNELL 14 65
47 W-196 FGS Cuttings 29.435251 -81.31732 BUNNELL 5 65
48 W-197 FGS Cuttings 29.409561 -81.367767 BUNNELL 11 120








FLORIDA GEOLOGICAL SURVEY


Map Well Data Sample Latitude Longitude 24K Quad Elevation Total
ID Label Source Type (ft) Depth (ft)
49 W-198 FGS Cuttings 29.353407 -81.510599 WELAKA SE 45 100
50 W-199 FGS Cuttings 29.270276 -81.645293 SALT SPRINGS 38 80
51 W-200 FGS Cuttings 29.313234 -81.771858 LAKE KERR 50 120
52 W-201 FGS Cuttings 29.182203 -81.890483 LYNNE 62 100
53 W-202 FGS Cuttings 29.156872 -81.955242 LYNNE 64 75
54 W-245 FGS Cuttings 29.029765 -81.293389 DELAND 57 264
55 W-939 FGS Cuttings 29.035512 -81.326351 DELAND 84 290
56 W-1129 FGS Cuttings 29.492157 -81.913262 EUREKA DAM 18 55
57 W-1131 FGS Cuttings 29.448032 -81.91754 EUREKA DAM 76 56.7
58 W-1132 FGS Cuttings 29.432991 -81.934441 EUREKA DAM 18 69
59 W-1133 FGS Cuttings 29.432991 -81.934441 EUREKA DAM 18 55.4
60 W-1134 FGS Cuttings 29.416018 -81.921456 EUREKA DAM 19 68
61 W-1135 FGS Cuttings 29.404321 -81.917402 EUREKA DAM 19 75
62 W-1136 FGS Cuttings 29.375268 -81.900744 EUREKA DAM 33 85
63 W-1137 FGS Cuttings 29.375268 -81.900744 EUREKA DAM 33 97
64 W-1139 FGS Cuttings 29.317171 -81.899779 FORT MCCOY 25 78
65 W-1140 FGS Cuttings 29.302207 -81.916158 FORT MCCOY 30 54.8
66 W-1141 FGS Cuttings 29.28741 -81.932539 FORT MCCOY 29 62.3
67 W-1142 FGS Cuttings 29.274113 -81.955438 FORT MCCOY 45 77.5
68 W-1143 FGS Cuttings 29.259654 -81.955344 FORT MCCOY 30 82.5
69 W-1144 FGS Cuttings 29.244925 -81.978438 LYNNE 33 96
70 W-1147 FGS Cuttings 29.182281 -82.016943 OCALA EAST 56 100
71 W-1148 FGS Cuttings 29.182281 -82.016943 OCALA EAST 56 69
72 W-1149 FGS Cuttings 29.182281 -82.016943 OCALA EAST 56 70
73 W-1150 FGS Cuttings 29.185918 -82.012733 OCALA EAST 57 92
74 W-1151 FGS Cuttings 29.182281 -82.016943 OCALA EAST 56 81
75 W-1152 FGS Cuttings 29.171454 -82.029134 OCALA EAST 39 112
76 W-1153 FGS Cuttings 29.162065 -82.039221 OCALA EAST 67 91.9
77 W-1491 FGS Cuttings 29.470614 -81.302613 BUNNELL 14 117
78 W-1520 FGS Cuttings 29.363512 -81.342814 CODYS CORNER 9 130
79 W-1707 FGS Cuttings 28.982555 -82.041749 OXFORD 86 165
80 W-1712 FGS Cuttings 28.987422 -82.018405 OXFORD 76 111
81 W-1717 FGS Cuttings 29.230913 -81.265922 LAKE DIAS 33 150
82 W-1746 FGS Cuttings 29.230913 -81.265922 LAKE DIAS 33 5418
83 W-1762 FGS Cuttings 28.987222 -82.018611 OXFORD 76 141
84 W-1966 FGS Cuttings 29.069711 -81.976674 LAKE WEIR 108 141
85 W-2216 FGS Cuttings 29.184444 -81.881666 LYNNE 65 125
86 W-2444 FGS Cuttings 29.474951 -81.248174 FLAGLER BEACH WEST 19 80
87 W-2944 FGS Cuttings 29.210536 -81.043388 DAYTONA BEACH 9 282
88 W-2951 FGS Cuttings 29.211925 -81.043945 DAYTONA BEACH 9 167
89 W-3059 FGS Cuttings 29.492539 -81.151525 FLAGLER BEACH WEST 10 7077
90 W-3060 FGS Cuttings 29.492658 -81.155062 FLAGLER BEACH WEST 10 70
91 W-3183 FGS Cuttings 29.000774 -81.300398 DELAND 32 400
92 W-3291 FGS Cuttings 29.054688 -81.929566 LAKE WEIR 59 210
93 W-3292 FGS Cuttings 29.040086 -81.929522 LAKE WEIR 51 160
94 W-3472 FGS Cuttings 29.349634 -81.087677 ORMOND BEACH 11 147
95 W-3476 FGS Cuttings 29.162756 -81.100615 DAYTONA BEACH 24 496
96 W-3477 FGS Cuttings 29.191839 -81.07104 DAYTONA BEACH 27 505
97 W-3479 FGS Cuttings 29.48909 -81.147133 FLAGLER BEACH WEST 13 81
98 W-3527 FGS Cuttings 29.102162 -81.213429 DAYTONA BEACH SW 40 351
99 W-3528 FGS Cuttings 29.15803 -81.098204 DAYTONA BEACH 29 235
100 W-3532 FGS Cuttings 29.158755 -81.107694 DAYTONA BEACH 27 235
101 W-3534 FGS Cuttings 29.158596 -81.103186 DAYTONA BEACH 28 234
102 W-3535 FGS Cuttings 29.162735 -81.096405 DAYTONA BEACH 25 211
103 W-3540 FGS Cuttings 29.180526 -81.079953 DAYTONA BEACH 28 498








OPEN-FILE REPORT 101


Map Well Data Sample Latitude Longitude 24K Quad Elevation Total
ID Label Source Type (ft) Depth (ft)
104 W-3569 FGS Cuttings 29.199703 -81.040054 DAYTONA BEACH 6 200
105 W-3573 FGS Cuttings 29.199703 -81.040054 DAYTONA BEACH 6 160
106 W-3574 FGS Cuttings 29.199981 -81.033668 DAYTONA BEACH 7 160
107 W-3651 FGS Cuttings 29.433462 -81.149946 FLAGLER BEACH WEST 10 114
108 W-3653 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 182
109 W-3697 FGS Cuttings 29.064752 -81.300456 DELAND 82 138
110 W-3888 FGS Cuttings 29.106998 -81.619507 ALEXANDER SPRINGS 52 35
111 W-3889 FGS Cuttings 29.180555 -81.890277 LYNNE 61 171
112 W-3975 FGS Cuttings 29.474993 -81.672301 WELAKA 20 483
113 W-4057 FGS Cuttings 29.308011 -81.316391 CODYS CORNER 23 146
114 W-4059 FGS Cuttings 29.492423 -81.673809 WELAKA 21 80
115 W-4062 FGS Cuttings 29.496287 -81.589353 CRESCENT CITY 64 176
116 W-4067 FGS Cuttings 29.333713 -81.342141 CODYS CORNER 13 180
117 W-4223 FGS Cuttings 29.192808 -81.066501 DAYTONA BEACH 27 205
118 W-4226 FGS Cuttings 29.173609 -80.983332 PORT ORANGE 14 170
119 W-4227 FGS Cuttings 29.225639 -81.006629 DAYTONA BEACH 17 185
120 W-4228 FGS Cuttings 29.194704 -81.059776 DAYTONA BEACH 31 225
121 W-4580 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93
122 W-4581 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93
123 W-4582 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93
124 W-4583 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93
125 W-4584 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 90
126 W-4591 FGS Cuttings 29.35134 -81.087898 ORMOND BEACH 9 93
127 W-4619 FGS Cuttings 29.270812 -81.068115 ORMOND BEACH 5 198
128 W-4622 FGS Cuttings 29.290667 -81.090834 ORMOND BEACH 38 201
129 W-5021 FGS Cuttings 29.476337 -81.673419 WELAKA 21 87
130 W-5029 FGS Cuttings 29.47379 -81.182468 FLAGLER BEACH WEST 23 115
131 W-5037 FGS Cuttings 29.409352 -81.305411 BUNNELL 13 76
132 W-5038 FGS Cuttings 29.384937 -81.188446 FLAGLER BEACH WEST 28 103
133 W-5040 FGS Cuttings 29.353809 -81.252695 CODYS CORNER 18 171
134 W-5309 FGS Cuttings 29.20207 -81.050299 DAYTONA BEACH 30 275
135 W-5430 FGS Cuttings 29.016345 -81.637199 FARLES LAKE 46 147
136 W-5489 FGS Cuttings 29.184116 -81.006367 DAYTONA BEACH 5 148
137 W-5607 FGS Cuttings 29.035671 -81.282938 DELAND 85 110
138 W-5613 FGS Cuttings 29.021047 -81.290983 DELAND 41 190
139 W-5614 FGS Cuttings 29.041225 -81.283379 DELAND 75 315
140 W-5743 FGS Cuttings 29.248311 -81.455902 PIERSON 68 250
141 W-5745 FGS Cuttings 29.053055 -82.039166 BELLEVIEW 84 124
142 W-5746 FGS Cuttings 29.474653 -81.741353 WELAKA 12 200
143 W-5758 FGS Cuttings 29.246366 -81.456459 PIERSON 70 250
144 W-5784 FGS Cuttings 29.20207 -81.050299 DAYTONA BEACH 30 210
145 W-5789 FGS Cuttings 29.005555 -82.010277 BELLEVIEW 71 112
146 W-6016 FGS Cuttings 29.034722 -82.043333 BELLEVIEW 89 800
147 W-6110 FGS Cuttings 29.037668 -81.319483 DELAND 71 304
148 W-6273 FGS Cuttings 29.138611 -81.849999 HALFMOON LAKE 54 141
149 W-6326 FGS Cuttings 29.01506 -81.372187 DELAND 18 101.5
150 W-6328 FGS Cuttings 29.190259 -81.075889 DAYTONA BEACH 28 210
151 W-6353 FGS Cuttings 29.0383 -81.302922 DELAND 65 220
152 W-7172 FGS Cuttings 29.011171 -81.346062 DELAND 49 95
153 W-7173 FGS Cuttings 29.011171 -81.346062 DELAND 49 198
154 W-7383 FGS Cuttings 29.226329 -82.049686 OCALA EAST 55 110
155 W-7697 FGS Cuttings 29.011111 -82.045555 BELLEVIEW 95 230
156 W-7781 FGS Cuttings 29.429444 -81.859194 LAKE DELANCY 139 328
157 W-7835 FGS Cuttings 29.040086 -81.929522 LAKE WEIR 51 180
158 W-7871 FGS Cuttings 29.172836 -81.084388 DAYTONA BEACH 22 200








FLORIDA GEOLOGICAL SURVEY


Map Well Data Sample Latitude Longitude 24K Quad Elevation Total
ID Label Source Type (ft) Depth (ft)
159 W-7917 FGS Cuttings 29.175255 -82.008141 OCALA EAST 54 180
160 W-8075 FGS Cuttings 28.987222 -82.043611 OXFORD 70 285
161 W-8108 FGS Cuttings 29.027097 -81.292974 DELAND 46 253
162 W-8132 FGS Cuttings 29.127777 -81.888611 LYNNE 108 105
163 W-8407 FGS Cuttings 29.201016 -81.929977 LYNNE 59 125
164 W-8411 FGS Cuttings 29.191922 -82.030363 OCALA EAST 39 192
165 W-8412 FGS Cuttings 29.266919 -81.916475 FORT MCCOY 73 165
166 W-8413 FGS Cuttings 29.322472 -81.966477 FORT MCCOY 66 173
167 W-8414 FGS Cuttings 29.141922 -81.977586 LYNNE 55 219
168 W-8453 FGS Cuttings 29.115539 -81.186447 DAYTONA BEACH SW 41 305
169 W-8455 FGS Cuttings 29.047492 -81.003929 SAMSULA 25 700
170 W-8458 FGS Cuttings 29.079998 -81.148306 DAYTONA BEACH SW 40 310
171 W-8503 FGS Cuttings 29.0522 -81.304741 DELAND 72 407
172 W-8562 FGS Cuttings 29.21535 -82.045555 OCALA EAST 38 105
173 W-8593 FGS Cuttings 29.145259 -81.145889 DAYTONA BEACH NW 43 100
174 W-8594 FGS Cuttings 29.026103 -81.187168 DAYTONA BEACH SW 38 91
175 W-10259 FGS Cuttings 29.325168 -81.114834 ORMOND BEACH 29 440
176 W-10304 FGS Cuttings 29.433462 -81.149946 FLAGLER BEACH WEST 10 88
177 W-10307 FGS Cuttings 29.505803 -81.884531 KEUKA 40 180
178 W-10332 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 228
179 W-10395 FGS Cuttings 29.214941 -82.012677 OCALA EAST 62 160
180 W-10430 FGS Cuttings 29.433462 -81.149946 FLAGLER BEACH WEST 10 66
181 W-10578 FGS Cuttings 29.069308 -82.012274 BELLEVIEW 99 158
182 W-10728 FGS Cuttings 28.996786 -81.716047 UMATILLA 51 130
183 W-10788 FGS Cuttings 29.274505 -81.832016 LAKE KERR 132 125
184 W-11046 FGS Cuttings 29.240535 -81.045608 DAYTONA BEACH 12 220
185 W-11099 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 300
186 W-11175 FGS Cuttings 29.060342 -81.264904 DELAND 70 550
187 W-11261 FGS Cuttings 29.422538 -81.733387 WELAKA 31 190
188 W-11301 FGS Cuttings 29.137546 -81.343747 LAKE DIAS 52 150
189 W-11329 FGS Cuttings 29.199448 -81.119452 DAYTONA BEACH 25 160
190 W-11394 FGS Cuttings 29.326639 -81.773417 LAKE KERR 87 140
191 W-11512 FGS Cuttings 29.21535 -82.045555 OCALA EAST 38 110
192 W-11520 FGS Cuttings 29.146102 -81.031728 DAYTONA BEACH 31 205
193 W-11569 FGS Cuttings 28.991614 -81.298574 ORANGE CITY 61 210
194 W-11648 FGS Cuttings 29.083072 -81.877976 LAKE WEIR 70 210
195 W-11694 FGS Cuttings 29.235221 -81.031039 DAYTONA BEACH 3 205
196 W-11696 FGS Cuttings 29.243867 -81.463401 PIERSON 75 200
197 W-11730 FGS Cuttings 29.171666 -81.837777 HALFMOON LAKE 65 160
198 W-11776 FGS Cuttings 29.336033 -81.131173 FAVORETTA 52 160
199 W-11828 FGS Cuttings 29.094752 -81.303576 DELAND 64 230
200 W-11848 FGS Cuttings 29.389014 -81.086141 FLAGLER BEACH EAST 15 155
201 W-11861 FGS Cuttings 29.406891 -81.158442 FLAGLER BEACH WEST 27 220
202 W-11929 FGS Cuttings 29.119536 -81.512696 ALEXANDER SPRINGS 3 114
203 W-11934 FGS Cuttings 29.164231 -81.534035 ASTOR 8 163
204 W-12014 FGS Cuttings 29.133777 -81.028007 DAYTONA BEACH 31 160
205 W-12021 FGS Core 29.233569 -81.17645 DAYTONA BEACH NW 27 71
206 W-12022 FGS Core 29.207202 -81.195617 DAYTONA BEACH NW 35 48
207 W-12023 FGS Core 29.163871 -81.21228 DAYTONA BEACH NW 39 57
208 W-12024 FGS Core 29.191925 -81.22895 DAYTONA BEACH NW 38 73
209 W-12025 FGS Core 29.218591 -81.219505 DAYTONA BEACH NW 33 71
210 W-12026 FGS Core 29.185258 -81.180335 DAYTONA BEACH NW 36 84
211 W-12027 FGS Core 29.020818 -81.204223 DAYTONA BEACH SW 39 74
212 W-12028 FGS Core 29.239147 -81.235336 DAYTONA BEACH NW 35 75
213 W-12029 FGS Core 29.141927 -81.238395 DAYTONA BEACH NW 41 57.5








OPEN-FILE REPORT 101


Map Well Data Sample Latitude Longitude 24K Quad Elevation Total
ID Label Source Type (ft) Depth (ft)
214 W-12031 FGS Core 29.09165 -81.160614 DAYTONA BEACH SW 41 92
215 W-12032 FGS Core 29.025817 -81.148117 DAYTONA BEACH SW 41 82
216 W-12034 FGS Core 29.225257 -81.252281 LAKE DIAS 37 92
217 W-12058 FGS Cuttings 29.377145 -81.131955 FLAGLER BEACH WEST 34 180
218 W-12059 FGS Cuttings 29.373439 -81.139285 FAVORETTA 21 260
219 W-12060 FGS Cuttings 29.38338 -81.131826 FLAGLER BEACH WEST 26 200
220 W-12061 FGS Cuttings 29.389809 -81.144256 FLAGLER BEACH WEST 23 120
221 W-12142 FGS Cuttings 29.007156 -81.342233 DELAND 56 230
222 W-12154 FGS Cuttings 29.090555 -81.068138 SAMSULA 21 100
223 W-12166 FGS Cuttings 29.26748 -81.077278 ORMOND BEACH 27 180
224 W-12228 FGS Cuttings 29.250531 -81.439074 SEVILLE 59 190
225 W-12340 FGS Cuttings 29.431675 -81.214119 FLAGLER BEACH WEST 23 325
226 W-12385 FGS Cuttings 29.136231 -81.145109 DAYTONA BEACH NW 43 150
227 W-12409 FGS Cuttings 29.201388 -81.913263 LYNNE 69 192
228 W-12632 FGS Cuttings 29.237521 -81.097118 DAYTONA BEACH 26 200
229 W-12633 FGS Cuttings 29.259533 -81.108549 ORMOND BEACH 20 200
230 W-12796 FGS Cuttings 29.19996 -81.061095 DAYTONA BEACH 29 150
231 W-12797 FGS Cuttings 29.146599 -81.153515 DAYTONA BEACH NW 42 140
232 W-12801 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 200
233 W-12808 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 220
234 W-12809 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 222
235 W-12810 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 210
236 W-12811 FGS Cuttings 29.170149 -81.169047 DAYTONA BEACH NW 38 210
237 W-12904 FGS Cuttings 28.99751 -80.966672 EDGEWATER 29 210
238 W-12950 FGS Cuttings 29.083639 -81.067998 SAMSULA 22 120
239 W-13086 FGS Cuttings 29.360588 -81.966944 FORT MCCOY 73 103
240 W-13102 FGS Cuttings 29.491375 -81.951944 EUREKA DAM 64 160
241 W-13235 FGS Cuttings 29.065145 -81.250656 DELAND 50 120
242 W-13236 FGS Cuttings 29.263173 -81.110494 ORMOND BEACH 16 80
243 W-13414 FGS Cuttings 29.446626 -81.296821 BUNNELL 11 90
244 W-13415 FGS Cuttings 29.446626 -81.296821 BUNNELL 11 100
245 W-13416 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 200
246 W-13417 FGS Cuttings 29.279948 -81.070545 ORMOND BEACH 8 130
247 W-13426 FGS Cuttings 29.25944 -81.125108 FAVORETTA 8 100
248 W-13427 FGS Cuttings 29.162259 -81.01886 DAYTONA BEACH 9 80
249 W-13431 FGS Cuttings 29.431372 -81.230577 FLAGLER BEACH WEST 23 140
250 W-13440 FGS Cuttings 29.445797 -81.262863 BUNNELL 13 8856
251 W-13456 FGS Cuttings 29.145091 -81.145551 DAYTONA BEACH NW 44 270
252 W-13461 FGS Cuttings 29.145091 -81.145551 DAYTONA BEACH NW 44 270
253 W-13513 FGS Cuttings 29.431372 -81.230577 FLAGLER BEACH WEST 23 80
254 W-13546 FGS Cuttings 29.03224 -81.337657 DELAND 67 400
255 W-13595 FGS Cuttings 29.146102 -81.031728 DAYTONA BEACH 31 200
256 W-13596 FGS Cuttings 29.146102 -81.031728 DAYTONA BEACH 31 200
257 W-13678 FGS Cuttings 29.446626 -81.296821 BUNNELL 11 140
258 W-13689 FGS Cuttings 29.016896 -81.223145 DAYTONA BEACH SW 43 200
259 W-13695 FGS Cuttings 29.167776 -81.299602 LAKE DIAS 35 160
260 W-13837 FGS Cuttings 29.197252 -81.599341 ASTOR 0 320
261 W-13864 FGS Cuttings 29.188051 -81.049559 DAYTONA BEACH 30 190
262 W-14180 FGS Cuttings 29.371822 -81.558277 WELAKA SE 24 157
263 W-14187 FGS Cuttings 29.446532 -81.197911 FLAGLER BEACH WEST 23 160
264 W-14188 FGS Cuttings 29.446532 -81.197911 FLAGLER BEACH WEST 23 170
265 W-14189 FGS Cuttings 29.446532 -81.197911 FLAGLER BEACH WEST 23 170
266 W-14190 FGS Cuttings 29.446532 -81.197911 FLAGLER BEACH WEST 23 115
267 W-14264 FGS Cuttings 29.188051 -81.049559 DAYTONA BEACH 30 185
268 W-14315 FGS Core 29.181644 -81.713966 JUNIPER SPRINGS 48 280








FLORIDA GEOLOGICAL SURVEY


Map Well Data Sample Latitude Longitude 24K Quad Elevation Total
ID Label Source Type (ft) Depth (ft)
269 W-14316 FGS Core 29.147061 -81.664883 JUNIPER SPRINGS 110 140
270 W-14327 FGS Core 29.175 -81.715555 JUNIPER SPRINGS 72 112
271 W-14353 FGS Core 29.514721 -81.662585 SATSUMA 89 162
272 W-14432 FGS Cuttings 29.242616 -81.046075 DAYTONA BEACH 5 210
273 W-14623 FGS Cuttings 29.14277 -81.035394 DAYTONA BEACH 29 210
274 W-14625 FGS Cuttings 29.14277 -81.035394 DAYTONA BEACH 29 200
275 W-14751 FGS Core 29.105277 -81.655 FARLES LAKE 60 102
276 W-14763 FGS Cuttings 29.483917 -81.527712 CRESCENT CITY 0 157
277 W-14965 FGS Cuttings 29.505542 -81.291653 ESPANOLA 28 220
278 W-14966 FGS Cuttings 29.511425 -81.287819 ESPANOLA 28 220
279 W-14967 FGS Cuttings 29.500002 -81.27917 BUNNELL 27 220
280 W-14968 FGS Cuttings 29.504171 -81.266708 ESPANOLA 28 210
281 W-15109 FGS Cuttings 29.287264 -81.159063 FAVORETTA 23 200
282 W-15141 FGS Cuttings 29.112307 -81.053498 SAMSULA 25 180
283 W-15201 FGS Cuttings 28.965459 -81.655433 UMATILLA 68 368
284 W-15312 FGS Cuttings 29.083836 -82.012291 BELLEVIEW 104 240
285 W-15362 FGS Cuttings 29.207384 -81.409683 PIERSON 42 370
286 W-15635 FGS Cuttings 29.020728 -81.299304 DELAND 49 400
287 W-15651 FGS Cuttings 29.140633 -81.14964 DAYTONA BEACH NW 44 300
288 W-15772 FGS Cuttings 29.100462 -81.143198 DAYTONA BEACH SW 41 300
289 W-15780 FGS Cuttings 29.186469 -81.152616 DAYTONA BEACH NW 29 300
290 W-15835 FGS Cuttings 29.094613 -81.362092 DELAND 52 315
291 W-15862 FGS Cuttings 29.222891 -81.468786 PIERSON 41 200
292 W-15863 FGS Cuttings 29.222891 -81.468786 PIERSON 41 200
293 W-15994 FGS Cuttings 29.143395 -81.129309 DAYTONA BEACH NW 43 818
294 W-15995 FGS Cuttings 29.185305 -81.072731 DAYTONA BEACH 26 820
295 W-16007 FGS Core 29.103013 -81.315333 DELAND 90 90
296 W-16008 FGS Core 29.174972 -81.452546 PIERSON 32 90
297 W-16009 FGS Core 29.257553 -81.12047 ORMOND BEACH 21 75
298 W-16164 FGS Cuttings 29.164925 -81.153526 DAYTONA BEACH NW 36 350
299 W-16174 FGS Cuttings 29.375061 -81.917222 EUREKA DAM 68 190
300 W-16175 FGS Cuttings 29.145091 -81.145551 DAYTONA BEACH NW 44 330
301 W-16217 FGS Cuttings 29.313542 -81.105587 ORMOND BEACH 17 104
302 W-16219 FGS Cuttings 29.336666 -81.709166 SALT SPRINGS 1 200
303 W-16227 FGS Cuttings 29.27645 -81.684166 SALT SPRINGS 41 200
304 W-16278 FGS Cuttings 29.020929 -81.299259 DELAND 48 370
305 W-16280 FGS Cuttings 29.462172 -81.934722 EUREKA DAM 37 264
306 W-16557 FGS Cuttings 29.17212 -81.96295 LYNNE 70 300
307 W-16563 FGS Cuttings 28.967222 -81.979252 LADY LAKE 79 426
308 W-16801 FGS Cuttings 29.281447 -81.066859 ORMOND BEACH 7 195
309 W-16823 FGS Cuttings 29.257109 -81.114031 ORMOND BEACH 25 130
310 W-16831 FGS Cuttings 29.029145 -81.260806 DELAND 70 150
311 W-17060 FGS Cuttings 29.104148 -81.308952 DELAND 83 460
312 W-17154 FGS Cuttings 29.141944 -81.364999 LAKE DIAS 19 460
313 W-17175 FGS Cuttings 29.377782 -81.526741 CRESCENT CITY 43 400
314 W-17255 FGS Cuttings 29.390277 -81.967777 EUREKA DAM 47 44.5
315 W-17274 FGS Cuttings 29.363333 -81.684722 SALT SPRINGS 23 460
316 W-17475 FGS Cuttings 29.465833 -81.651666 WELAKA 51 16
317 W-17476 FGS Cuttings 29.463888 -81.651666 WELAKA 45 41
318 W-17477 FGS Cuttings 29.464722 -81.653055 WELAKA 30 15
319 W-17531 FGS Cuttings 29.179166 -81.0625 DAYTONA BEACH 28 970
320 W-17532 FGS Cuttings 29.097777 -81.273888 DELAND 49 140
321 W-17537 FGS Cuttings 29.097777 -81.273888 DELAND 49 66
322 W-17561 FGS Cuttings 29.429693 -81.858975 LAKE DELANCY 140 136
323 W-17562 FGS Cuttings 29.091944 -81.708611 FARLES LAKE 92 81








OPEN-FILE REPORT 101


Map Well Data Sample Latitude Longitude 24K Quad Elevation Total
ID Label Source Type (ft) Depth (ft)
324 W-17563 FGS Cuttings 29.268333 -81.82 LAKE KERR 140 96
325 W-17564 FGS Cuttings 29.282499 -81.770833 LAKE KERR 67 76
326 W-17565 FGS Cuttings 29.360833 -81.856944 LAKE KERR 131 81
327 W-17566 FGS Cuttings 29.105277 -81.813055 LAKE MARY 112 101
328 W-17568 FGS Cuttings 29.298055 -81.696666 SALT SPRINGS 41 126
329 W-17569 FGS Cuttings 29.471111 -81.860277 LAKE DELANCY 163 91
330 W-17659 FGS Cuttings 28.968055 -82.011666 OXFORD 68 101
331 W-17660 FGS Cuttings 29.354429 -81.46245 SEVILLE 27 25
332 W-17686 FGS Cuttings 29.032202 -81.556458 ALEXANDER SPRINGS 46 91
333 W-17764 FGS Core 29.3208 -81.179199 FAVORETTA 23 151
334 W-18061 FGS Cuttings 29.499166 -81.958333 EUREKA DAM 81 141
335 W-18250 FGS Cuttings 29.284722 -81.126388 FAVORETTA 25 90
336 W-18267 FGS Cuttings 29.386111 -81.972777 EUREKA DAM 56 180
337 W-18279 FGS Cuttings 29.428611 -81.856388 LAKE DELANCY 139 380
338 W-18281 FGS Cuttings 29.321666 -81.539444 WELAKA SE 20 110
339 W-18284 FGS Cuttings 29.251666 -81.507222 WELAKA SE 12 170
340 W-18287 FGS Cuttings 29.431944 -81.513888 CRESCENT CITY 37 160
341 W-18297 FGS Cuttings 29.499166 -81.958333 EUREKA DAM 81 210
342 W-18814 FGS Core 29.176666 -81.116666 DAYTONA BEACH 28 1006
343 W-18825 FGS Cuttings 29.508055 -81.161944 BEVERLY BEACH 18 290
344 W-18863 FGS Core 29.211111 -81.086944 DAYTONA BEACH 28 1000
345 W-18998 FGS Core 29.068058 -81.289174 DELAND 72 870
346 W-19036 FGS Core 29.169166 -81.641943 JUNIPER SPRINGS 67 195
347 W-19060 FGS Core 29.411361 -81.305111 BUNNELL 13 92
348 W-19213 FGS Core 29.431916 -81.513911 CRESCENT CITY 37 112
349 W-19240 FGS Core 29.091389 -81.044167 SAMSULA 23 810