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STATE OF FLORIDA STATE BOARD OF CONSERVATION FLORIDA GEOLOGICAL SURVEY Robert O. Vernon, Director GEOLOGICAL BULLETIN NO. 42 THE LIMESTONE RESOURCES OF WASHINGTON, HOLMES AND JACKSON COUNTIES, FLORIDA By William D. Reves Published for THE FLORIDA GEOLOGICAL SURVEY TALLAHASSEE 1961 FLORIDA STATE BOARD OF CONSERVATION FARRIS BRYANT Governor TOM ADAMS Secretary of State J. EDWIN LARSON Treasurer THOMAS D. BAILEY Superintendent Public Instruction RICHARD ERVIN Attorney General RAY E. GREEN Comptroller DOYLE CONNER Commissioner of Agriculture ROBERT O. VERNON State Geologist and Administrator Oil and Gas Division LETTER OF TRANSMITTAL Jlorida /eoloqical Survey eCallalassee May 16, 1960 Honorable Farris Bryant, Chairman Florida State Board of Conservation Tallahassee, Florida Dear Governor Bryant: I am pleased to present the results of a study on "The Limestone Resources of Washington, Holmes and Jackson Counties, Florida," prepared by William D. Reves, economic geologist with this depart- ment. This area is one of the few in Florida that has lost population, and the presentation of these data will assist in establishment of additional industry, greatly needed to stabilize the economy of these counties. We have worked closely with several land owners, the State Road Department and potential producers in an attempt to start the economic exploitation of these limestone resources. We have also coupled this study with one on the clays of the area, and it is anticipated that both clays and limestones can be utilized and combined in some manufacturing process. Respectfully yours, Robert O. Vernon, Director Completed manuscript received December 1, 1960 Published for the Florida Geological Survey by E. O. Painter Printing Company DeLand, Florida iv TABLE OF CONTENTS Page Acknowledgments -...-. ... ----- ------------- ------ ix Introduction -..--- ----- ---- -. ------- -. 1 Methods of investigation --...........- ----------- -- --- 2 General .-- ---- ------ ------ 2 Field sampling ...--------.........------ -- -------. 4 Laboratory methods ...... ..----- --..... -- --- --- 4 Stratigraphy ------------.. ..... 5 General ..........--------------........ ---.. --- 5 Eocene series 5--..... ---------- -- .. .......----- 5 Jackson stage ------- --.......- .... --- --- 5 Crystal River formation --......... ----- 5 Oligocene series --..----- ..... ------ 7 Vicksburg stage .-.......------.-- .. --- -------- 7 Marianna limestone --- -- ... -- 7 Byram formation ........... ---- ------ 8 Suwannee limestone ---.-----......... ------ 9 Miocene series .------------- --------- . . ---- -- ------...- 10 Tampa stage -----------------.......- ..-... ---- -- 10 St. Marks and Chattahoochee formations --. ... 10 Alum Bluff stage .....-- --.. .....-- -- -------- 12 Chipola formation, Shoal River formation, Hawthorn formation and unnamed coarse plastics --....-~.. .-- ... 12 Choctawhatchee stage .....------------ ..... --------.---- 13 "Choctawhatchee formation" .. ----- .- ...... -- 13 Post-Miocene surficial sediments ... ---- ---- --- -- 15 Limestone areas of potential economic importance ..... 16 W ashington County ------------------....-...--- ..- .. ..... 16 General .. --------- ----------... -----. . ... ... .. 16 Areas ...... --------.-.......- -- .. ------ --------. 18 Other locations ..-- ..... ---------- -..- ....- 30 Holmes County .-------- -- ----- - 31 General -- -- -_ .---.... 31 Areas ..-....-....-.------------- ------- ----. 33 Other locations --...---- --..- ............----- -- 37 Jackson County -..--..........------ ...... ..---. 37 General .........------------ -- ----- 37 Areas ..-....----------.... ------- --- 46 Locality description ---- -- -----------.- 67 Washington County .- -... ..-------- .. ..-----.. 67 Holmes County ..... ..--------- ----- ---- ------ 76 Jackson County --.....- -------- ---------- ---.. -- -- 78 Limestone as an economic deposit --. ................... .....- 89 General definition ..... ----------- ... ------... ....... 89 Uses ......--... ..-- -------- -- ----- ------------ 91 General ..--------- -------- --- -- 91 Lime ...------------------ -- ---92 Portland Cement ....... .............- Crushed and broken stone ..-...... Dimensional stone -...............-... Agricultural limestone .............. M ining -- .... .. .... .... ...... --- Transportation ---.....-- ............--...--... Highways ----------- ---- R ail .......... ......-- ... ..... W ater -........-----.......... .. ... A ir .. .............-... ..... .- Fuel and power ----. ---.. ...-... ..--....... Selected references .--..... ......... -..... Glossary ................- ...---- ---. Index ------ ------ -- ... -------- ILLUSTRATIONS Figure 1 Map of Washington, Holmes and Jackson counties, Florida ...... 2 Stratigraphic column for Washington, Holmes and Jackson counties, Florida -------------..........- 3 Index to topographic quadrangles ..-................-....-- .... 4 Northern one-quarter of the Wausau quadrangle and southern one- quarter of Chipley quadrangle showing potential limestone produc- ing Areas I and II, Washington County .......................-- 5 Northern one-half of Wausau quadrangle showing potential lime- stone producing Areas III and IV, Washington County ----- 6 West-central portion of Hinson crossroads quadrangle showing potential limestone producing Area V, Washington County -......- 7 Southeastern portion of the Redbay quadrangle showing sample location WHL-21, Washington County ...................... ...... 8 Northeastern portion of the Bennett quadrangle showing sample location WRL-22, Washington County ........................ 9 Northeastern portion of the Prosperity quadrangle showing poten- tial limestone producing Area I and sample location HRL-7, Holmes County . ..............-----......... 10 North central portion of Bonifay quadrangle showing sample loca- tion HRL-1 and north central portion of Ponce de Leon quadrangle showing sample location HRL-4, Holmes County --.................- 11 Southeastern portion of Ponce de Leon quadrangle showing sample location HRL-5, Walton County, and south-central portion of Prosperity quadrangle showing sample location HRL-6, Holmes County .......... ... ....- ......... ........--... --- . ----- 97 ------ 99 ..------........ 102 ----..... --..... 105 ......---......... 106 - .............- 108 . ....... ..... -. 108 .--- ..- 108 --.--..- ..---. 111 .............. ..- 113 - -.... .......- 113 .- ..- 113 -----. 116 -----119 Page 12 Southern one-half of Marianna Quadrangle showing potential lime- stone producing Areas I and II, and sample location JRL-19, Jackson County ---..........--......---------- ------------- 47 13 Northern one-half of Cottondale East Quadrangle showing poten- tial limestone producing Areas III and IV, Jackson County ......... .. 51 14 West-central portion of Cottondale East Quadrangle showing potential limestone producing Area V, Jackson County ----...-.- ...- 56 15 Southwestern portion of Sills Quadrangle showing potential lime- stone producing Area VI, Jackson County -----------..-.......-------- 59 16 Southwestern portion of Sneads Quadrangle showing potential limestone producing Area VII, Jackson County -...-..-.-----..--....-- 60 17 East-central and southeast portion of Sneads Quadrangle showing sample locations JRL-30, 31, 32, 33, Jackson County --........-- --- 62 18 North-central portion of Altha East Quadrangle showing sample location JRL-15, Jackson County ---......-.- - -------------- 63 19 South-central portion of Oakdale Quadrangle showing sample location JRL-14, Jackson County -........... ------------.-........ 64 20 Southwest portion of Cottondale East Quadrangle showing potential limestone producing Area VIII and sample location JRL-24, Jackson County ---.................. ------------ ... 66 21 Functions and uses of limestone ...--.........-----..-..- ............. 93 22 Some minerals used in the cement industry _- .-..... - ----------- 98 23 Typical highway section showing sand-clay base and limerock base- type roads _- ................... ---------- 103 24 Proposed route of Florida interstate highway system ...... ----- 109 25 Map showing highways of Panhandle Florida --.--..----..-- ..----- 110 26 Map showing rail shipping cost per ton for limerock and crushed stone ..----_-.. ..... .............. .... ----- .. .. ----------- 112 27 Route of proposed natural gas pipeline through the Florida Panhandle -.. .-.----- --------.--. ------- ........ 114 Table 1 Location data of Washington County samples ---............----- ----- 20 2 Chemical analysis of Washington County samples --.............--..------ 23 3 Location data of Holmes County samples ----------------- 35 4 Chemical analysis of Holmes County samples .._------------- 36 5 Location data of Jackson County samples ------------. 40 6 Chemical analysis of Jackson County samples --..--.--.--.---.---.- 43 7 Apparent consumption of lime -----...----...----------.-..........---- 96 8 Crushed limestone and shell production in Florida, 1956-1959 ----... 100 9 Soil test results of selected limestone samples from potential areas in Washington, Holmes and Jackson counties, Florida ....... _------ -------------- facing 102 vii ACKNOWLEDGMENTS I would like to express my appreciation to Dr. Robert O. Vernon, director of the Florida Geological Survey, through whose knowledge of the area and whose effort as director of the Survey, made possible this report. Appreciation is hereby acknowledged to the staff of the Florida Geological Survey, whose aid in general geological problems, map and manuscript preparation was of im- measurable value. The aid given by the staff of the U. S. Geological Survey, Ground Water Branch, proved quite helpful, as did the helpful discussions on stratigraphic nomenclature which were held with Professor H. K. Brooks of the Department of Geology and Geography at the University of Florida. The able field assistance of Mr. Wesley Shoemaker during the summer of 1958 is very much appreciated along with the many courtesies showvn by the people of Chipley and Washington County. The field guidance of Mr. J. R. Kirkland of Marianna and the conversations with many residents of Jackson and Holmes counties helped immeasurably. The chemical analyses of the limestone samples were determined by Mr. R. C. Crooks, director, and Mr. E. C. Petrie, assistant director, of the Fertilizer Laboratory of the Chemical Division, Florida Department of Agriculture. Some physical properties of limestone samples were measured by Mr. H. C. Weathers, engineer of tests, Mr. E. F. Shanley, soils engineer, and Mr. G. A. Barber, engineering aide, of the State Road Department Testing Labora- tory at Gainesville, Florida, and appreciation is expressed for the many other courtesies extended to the Florida Geological Survey by the Road Department Testing Laboratory. I would also like to express my appreciation to Mr. Sanders, district freight agent of the Atlantic Coast Line Railroad, who so kindly provided the information regarding rail freight rates. THE LIMESTONE RESOURCES OF WASHINGTON, HOLMES AND JACKSON COUNTIES, FLORIDA INTRODUCTION The Washington, Holmes and Jackson counties area has a large reserve of very high grade limestone, which has in the past sup- plied only a very local demand. In most instances, the limestone is almost chemically pure calcium carbonate. Generally the area is sparsely settled and remains one of the attractive unexploited portions of Florida. It seems unusual that this natural resource has been unexploited, especially so in recent years, since technology has advanced to where rock of this type can be utilized for so many products. It seems certain that in the future these limestones will materially aid in the economic and population growth of this part of Florida. This study, in addition to pointing out unused natural resources, is also a portion of the contribution of the Florida Geological Survey to the Florida State Rural Development Committee. Washington County, in which many of the deposits are situated, is one of the pilot counties of this committee, and Jackson and Holmes counties are designated by this committee as Rural Development counties. Washington, Holmes and Jackson counties adjoin and are located in the central portion of western Florida. Holmes County lies to the north of Washington County and both form the western border of Jackson County, Holmes and Washington counties are bounded on the west by Walton County, and on the south by Bay County. The northern boundary of Holmes County is Geneva County, Alabama. Jackson County is bounded on the south by Bay and Calhoun counties, on the east by the Chattahoochee and Apalachicola rivers and on the north by Houston County, Alabama. Holmes County is the smallest of the three counties, having a total land surface area of 506 square miles. Washington County has 625 square miles, and Jackson County, the largest of the three counties, has 942 square miles. The principal towns, which are the county seats, are Chipley in Washington County, Bonifay in Holmes County, and Marianna in Jackson County. The area is served by gas and electric power and is well pro- vided with highways. The Louisville and Nashville Railroad traverses the area, passing through the county seats. Regarding water transportation, the Apalachicola River, which 2 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO is the main artery of the Apalachicola-Chattahoochee-Flint river system, lies along the eastern border of the three-county area. The western border of the area is formed by the Choctawhatchee River which is the main artery of the Choctawhatchee-Pea river system. Lying between these river systems is the Chipola River, Holmes Creek and Wrights Creek (fig. 1). The current development of the Apalachicola-Chattahoochee-Flint river system provides the three-county area with access northward into Georgia and Alabama, and southward to the gulf coast area. Along the area's western boundary, studies are currently being made by State and Federal authorities to determine the feasibility of developing the Chocta- whatchee-Pea river system for water transport northward to Alabama and southward to the gulf coast area. Thus, the three- county area is potentially supplied with adequate waterways which could provide the area with inexpensive water transportation. Rock materials which lie along the river banks and also between the two river systems could readily be moved by this inexpensive method of transportation if both the rock deposits and the water- ways are fully developed. METHODS OF INVESTIGATION GENERAL The greatest single aid in investigation of the rock of the area was complete 71/2-minute topographic map coverage of Washington, Holmes and Jackson counties. Coupled with the above sheets, the two rather recent detailed geological bulletins with area maps (Vernon, 1942; Moore, 1955) covering the entire project, gave the ideal basic requirements for an investigation of this type. The "sinkhole" topography as contoured on the topographic sheet makes exposures of rock easily located. Samples were collected from previously unrecorded localities, as well as recorded localities. They were collected from sinks, quarries, surface exposures, road cuts, and river valleys. Sampled exposures ranged in vertical thickness from a few inches to over 30 feet. By far the best exposures are in sinks, some of which approach a quarter of a mile in diameter. The sample locations do not represent all of the areas in the three counties where rock bodies are either exposed or near the surface; however, they do represent a majority of those occurring along and adjacent to the paved and unpaved county, state and federal roads. The locations were chosen because of accessibility --~-H / WASHINGTON, HOLMES and JACKSON COUNTIES, FLORIDA o0 2 8 12 16 20 APPROX. SCALE R18W- R7W I R16W + R15W 4 R14W + R13W R12W RIIW RIOW R9W R8W + R7W Figure 1. Map of Washington, Holmes and Jackson counties, Florida. z F- --i z z z rf) z cli z U) 0 z 1-l c2 0 O H M tO m M 4 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO to mining, size of deposit, and for general lithologic information. Undoubtedly other favorable bodies of rock near the surface are unrecorded and one seeking for additional commercial deposits of limestone may wish to drill and prospect the area in more detail. FIELD SAMPLING When possible, channel samples of exposures were collected. In every case, at least 1 inch of the weathered surface of the rock was removed prior to sampling. The channel thus formed varied from 5 to 7 inches in width and was cut from the top to the bottom of the rock face. In instances where a continuous channel proved impractical, the channels cut were carefully staggered with the use of a land level, thus utilizing the natural slope of the land to make the higher rock faces attainable. The channel thus cleaned was completely sampled from top to bottom and into the fresh rock for an additional 1 to 11/ inches. All fragments were collected on a large cloth at the foot of the channel cut. No contamination was allowed. Bagged samples ranged from 25 to 35 pounds each. All elevations given in the text of this report were taken with an Aneroid altimeter and therefore these elevations should be expected to have a marginal error. LABORATORY METHODS To determine the percent of insolubles, the field samples were air dried and, because of their large size, split by quartering. The final split for analysis was made with a mechanical sample splitter. A 5-percent solution of HCI was used to digest the limestone. All drying and weighing was done at air temperature with controlled humidity. Since all insoluble residues were saved for future study, the above precautions were taken to minimize the alteration of the clay minerals within the limestone sample. Standard ASTM and AASHO methods were used by the State Road Department Testing Laboratory at Gainesville, Florida, in determining the liquid limit, plastic limit, plastic index, shrinkage limit and Los Angeles abrasion. The chemical analyses of the limestones were made, using standard chemical procedures as approved by the Florida Depart- ment of Agriculture Fertilizer Laboratory. LIMESTONE RESOURCES STRATIGRAPHY GENERAL Although many thousands of feet of sediments underlie the Crystal River formation, they are deleted from the stratigraphic section (fig. 2) of this report since they are not exposed nor are they available at depth, using present mining techniques. EOCENE SERIES JACKSON STAGE Crystal River Formation The name Crystal River formation was proposed by Puri (1953a, p. 130) as that stratum including all calcareous deposits of upper Eocene age lying stratigraphically between the older Williston formation and the younger Oligocene limestones. The Crystal River is the youngest formation of the Ocala group. The Ocala group is composed of the Inglis, Williston and Crystal River formations (fig. 2). The entire Crystal River formation is nowhere completely exposed since its surface is marked by an erosional unconformity. This formation is exposed in two generalized areas in Florida, in the northern portions of Holmes and Jackson counties, where it is associated with the Chattahoochee Arch, and in the northwestern portion of peninsular Florida where it has been brought to the surface by the Ocala uplift. The limestone underlies the entire State with the exception of areas along the axis of the uplift where it has been stripped off, and in irregular areas between Marion County and Cape Canaveral, where it has been undetected in deep drilling. The Crystal River formation ranges in color from white to cream and texturally it is granular. In places it occurs almost as a chalk and grades through microcoquina into coarse carbonate clastics, being made up largely of the tests of Foraminifera as well as the larger fossils. The rock is generally poorly indurated to indurated, with small local bodies of irregular well indurated re- crystallized rock. The Crystal River is made up almost entirely of calcium carbonate, having in many places less than 1 percent impurities. However, along the Alabama line as the ancestral shoreline is approached, the rock becomes more argillaceous and arenaceous. Puri (1957, p. 38) reported that a total of 310 feet of Crystal 6 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO E SYSTEM SERIES STAGE R and and and GROUP or FORMATION A PERIOD EPOCH AGE Unnamed sand, silt, clay and peat Silver Bluff Pamlico Wicomico Okefenokee Coharie Undifferentiated sands, silts,clays, soils and peats L LL1R~ I-C- 2c Li -I ?PLIO- PLEISTOCENE C-) iI~ C-, rLLA .4 C-, QD LJ lei L&J .j4~ ? LIOi PLuISTCN COO) S) -O - 0) 0 c 0 u c/ 04) n 3 a 0) o < "il "Choctawhatchee formation" Shoal River fm., Chipola fm., Hawthorn fm. Unnamed coarse clastics St. Marks limestone Chattahoochee fm. Suwannee limestone Byram formation Marianna limestone Crystal River formation Ocala group Williston formation Inglis formation Figure 2. Stratigraphic column for Washington, Holmes and Jackson counties, Florida. LaL C=, CD, LJ6J High level alluvial and deltaic deposits LLJ 1- LLJ LLJ CM LU LUJ LLJ a- LIMESTONE RESOURCES River is present in water well W-381 in Polk County and that over 300 feet of the formation is present in the subsurface of Jackson County. Vernon (1942, p. 42) reported that the top of the Ocala (Crystal River) strikes west-northwest and dips south at ap- proximately 12 feet per mile in Washington County, and that in Holmes County the dip increases to as much as 20 feet per mile with the beds striking northwest. Moore (1955, p. 32) noted that the Crystal River formation strikes northeast and regionally dips southeast in the eastern part of Jackson County and strikes east and west in the central and western parts of the county with the dip toward the south. These strikes and dips differ because of the effect of the doing along the Chattahoochee Arch. OLIGOCENE SERIES VICKSBURG STAGE Marianna Limestone The name Marianna limestone was suggested by Matson and Clapp (1909, p. 51-52) for those light gray, soft, porous limestones exposed in the vicinity of Marianna, Florida. The Marianna limestone is underlain by the Crystal River formation and overlain by the Byram formation (fig. 2). The Marianna is either exposed or near the surface, in a general east- west pattern from the Apalachicola River westward through Marianna and Cottondale, to the northeastern part of Washington. County east of Chipley. Vernon (1942) mapped a small exposure of Marianna in the south-central portion of Holmes County and a larger exposure in the west-central portion of Holmes County. The best exposures may be seen between Blue Springs and Cotton- dale, in Jackson County, where the Marianna is exposed along a northward facing escarpment. Eastward and westward from this area there is a general thickening of overlying younger material except in western Holmes County where Vernon (1942, p. 55) reported a sink (Vernon's locality H-37) exposing limestone quite near the surface. The Marianna limestone ranges in color from white to cream to light gray. It is a soft equigrained, chalky to fine grained, poorly indurated limestone, containing an abundant foraminiferal fauna. Small local pods or stringers of recrystallized limestone that have no particular preferred orientation, occur in the rock. 8 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO The formation averages about 95 percent calcium carbonate and where exposed it frequently has medium red-brown colored specks scattered on the surface as well as within the rock. Vernon (1942, p. 52) reported about 45 feet of Marianna lime- stone at depth in southwestern Holmes County and about 30 feet were encountered in the subsurface in the northeastern portion of Washington County. Moore (1955, p. 45) reported that in Jackson County the thickness of the Marianna is 35 to 40 feet in the exposed area, thinning to about 25 feet in the subsurface in the southern part of the county. Judging from the thicknesses as presented, there is apparently about 5 to 10 feet of thickening :westward between central Jackson County and southwestern Holmes County. The Marianna strikes west-northwest and dips'southward at about 11 feet per mile in Washington County according to Vernon (1942, p. 52) and strikes northwest dipping southward about 18 feet per mile in Holmes County. Moore (1955, p. 45) showed the Marianna as striking east-west in Jackson County and dipping toward the south at 13 feet per mile. However, Moore reported that south of T. 4 N., the dip increases to 64 feet per mile. Byram Formation The Byram formation was first recognized in Florida by Cooke and Mossom (1929, p. 74-76). This formation is underlain by the Marianna limestone and overlain by the Suwannee limestone, all of which are of the Oligocene series (fig. 2). The Byram has definitely been recognized in several exposures in Jackson County by Puri (1959, p. 88) although Moore (1955, p. 50) included the Byram within the younger Suwannee limestone. Vernon (1942, p. 59) included in the Suwannee in Washington and Holmes counties all limestones below Tampa and above Marianna. This includes the Byram within the Suwannee lime- stone. Vernon noted, however, that the Byram fauna does exist in these counties in sediments which cannot be lithologically separated from the Suwannee sediments. Therefore, not being a distinct lithologic unit, the Byram fauna is justly included within the Suwannee fauna and its corresponding lithology. Puri (1959, p. 9) and Cooke (1945, p. 82) both recognized the Byram as occurring in peninsular Florida. The Byram in Florida is buff, dense, indurated, finely crystalline dolomitic limestone and light grayish tan, poorly LIMESTONE RESOURCES indurated argillaceous magnesian limestone which varies to a massive or a fissile shale. Puri (1959, p. 89) described 16 to 19 feet of Byram as occurring in Jackson County, and Cooke (1945, p. 86) described as much as 7.5 feet of Byram as occurring in peninsular Florida with probably 10 feet occurring along the Suwannee River. At Natural Bridge in northwestern Florida, Cooke (1945, p. 82) reported that the Byram is at least 40 feet thick. The Byram appears to be essentially a littoral formation and care should be taken in areas where the Byram is thought to be present so, as not to confuse this formation with the weathered surface of other limestone formations. Suwannee Limestone The name Suwannee limestone was proposed by Cooke and Mansfield (1936, p. 71) for the exposures on the Suwannee River between Ellaville and White Springs in peninsular Florida. The Suwannee is underlain by the Byram formation and overlain by the younger Miocene Tampa sediments (fig. 2). The Suwannee limestone is a fairly well distributed formation in Florida and is exposed over rather large areas in northern peninsular Florida, as well as in Washington, Holmes and Jackson counties in West Florida. The Suwannee limestone is light cream to light gray, poorly indurated to well indurated, porous, massive, fossiliferous to coquinoid, coarse carbonate plastic limestone, frequently containing beds of soft, chalky limestone, which is quite similar to the Mari- anna limestone. The deposit frequently contains small irregular zones and narrow stringers of recrystallized well indurated lime- stone showing no preferred orientation. In the peninsula the Suwannee varies from a yellow to cream, hard, compact, fossiliferous, sometimes dense limestone to a cream, very porous, soft, granular calcarenite. Cooke (1945, p. 85) reported that in Hernando County, the Suwannee contains patches of hard and soft rock that are irregularly distributed and apparently show no relationship to bedding planes. Moore (1955, p. 51) described the Suwannee in Jackson County as consisting of tan to buff colored limestone, dolomitic limestones and dolomitic to calcareous clays, and (p. 50) included the Byram formation within the Suwannee limestone. Vernon (1942, p. 55) reported 45 feet of Suwannee in the 10 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO subsurface in southwestern Holmes County and an exposure of Suwannee at Falling Water Hill in Washington County, which exceeds 73 feet in thickness. Moore (1955, p. 51) reported that the thickness of the Suwannee varies from 5 to 12 feet in central Jackson County between Cottondale and Marianna, but that it increases in thickness in the subsurface in the south-central portion of the county to about 210 feet. The Suwannee strikes northwest across Holmes County and dips south about 20 feet per mile according to Vernon (1942, p. 60) and strikes west-northwest across Washington County with a dip to the south of about 10 feet per mile. Vernon also noted that the Suwannee equivalent near Pensacola is found at a depth of 1,200 feet, indicating an increase in dip toward the southwest. The Suwannee beds strike in a general east-west direction in Jackson County and Moore (1955, p. 51) noted that these beds may dip as much as 64 feet per mile in the south-central part of the county. Southward from Jackson County the beds probably flatten out and assume the regional dip of about 12 to 15 feet per mile. MIOCENE SERIES TAMPA STAGE St. Marks and Chattahoochee Formations The name Tampa was first used by Johnson in 1888 (p. 235). Vernon (1942, p. 68) defined the Tampa formation as those (Miocene) sediments above the Suwannee limestone and below the Alum Bluff group (fig. 2). Puri (1953b, p. 17) did not recognize the Tampa formation as such, but did recognize the Tampa sedi- ments as Vernon (1942, p. 68) delimited them. Puri described the Tampa sediments as the Tampa stage. Within the Tampa stage Puri delimits two really segregated "aspects" or facies of differing nature which are genetically related to the sedimentary body of the Tampa stage. Hence the Tampa stage includes two distinct facies which, if mappable, could be regarded as formations within the Tampa stage. Puri refers to these facies as formations in Panhandle Florida and calls them the St. Marks formation, which is the calcareous downdip facies of the Tampa stage, and the Chatta- hoochee formation, which is the updip silty clayey facies of the Tampa stage (1953b, p. 16). According to Puri (1959, p. 101) the Tampa stage included all Miocene sediments lying between the Oligocene series and the LIMESTONE RESOURCES Alum Bluff stage. His definition includes all sediments deposited between post-Vicksburg (Nodosaria blanpiedi zone of the Chickasawhay limestone) and pre-Alum Bluff ages, including those sediments exposed in the Florida Panhandle, as well as their equivalents in the central and western Gulf States. The type locality is at the famous Ballast Point location on Tampa Bay, and on Sixmile Creek at Orient, Hillsborough County, Florida. The Tampa formation, according to Vernon (1942, p. 68) gen- erally underlies a region of high relief and the surface configuration is controlled largely by overlying formations. Exposures of the Tampa in Washington and Holmes counties are rather rare and Vernon mapped the Tampa largely on the basis of structure. It is exposed at the base of the high hills in north- eastern Washington County and extends westward through the vicinity of Hard Labor Creek to Holmes Creek and Choctawhatchee River. In Holmes County, the Tampa is exposed near the base of hills centered in the vicinity of the town of Prosperity. Vernon (1942, p. 68) noted that the Tampa is predominantly limestone in Washington County, but green, argillaceous silts occur at the base of the section in Holmes County. In Jackson County, the Tampa is exposed in almost the entire southern part of the county. Moore (1955, p. 58) described the Tampa as being more calcareous along the Chipola River and in the southeastern part of the county, and more argillaceous in the western and northwestern part of the county. More specifically, Moore (1955, p. 58) described the Tampa as consisting of white, gray and green clays that are frequently calcareous, but in the southeastern part of the county white arenaceous and argillaceous limestones are present. In some instances the magnesium carbon- ate content of these limestones reaches as high as 35 percent. (See general discussion under Jackson County areas.) The entire formation is characterized by fine quartz grains. In addition to the few quartz grains, the gray and white clays and argillaceous lime- stones commonly contain scattered pellets of green clay similar to the Chattahoochee formation as exposed above Jim Woodruff Dam. Vernon (1942, p. 69) reported that the Tampa has a maximum thickness of 59 feet in Holmes County and an estimated 50 feet of Tampa in northern Washington County. Thinner deposits occur in other parts of the counties where they have been reduced by erosion. In Jackson County, according to Moore (1955, p. 58) the Tampa at Jim Woodruff Dam is 170 feet thick and thins to 100 12 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO feet at Sink Creek. In the southwestern part of the county near Round Lake the Tampa is about 70 feet thick. Vernon (1942, p. 69) reported that in Holmes County, the Tampa dips approximately 20 feet per mile and strikes northwest and that in Washington County, the Tampa dips approximately 12 feet per mile and strikes west-northwest. In Jackson County, Moore (p. 61) showed the Tampa to dip southward at about 13 feet per mile, with a general east-west strike. ALUM BLUFF STAGE Chipola Formation, Shoal River Formation, Hawthorn Formation and Unnamed Coarse Clastics According to Vernon (1942, p. 74) the Alum Bluff group of formations include those beds lying stratigraphically between the younger Choctawhatchee formation and the older Tampa formation (fig. 2). Vernon (1942, p. 75) questioned that the various lithologies of the Alum Bluff should be regarded as mappable formations and Puri (1953b, p. 16) regarded these varying lithologies as facies and formations of the Alum Bluff stage. For the purpose of this report the above formations are not differentiated, because of lack of detailed information regarding the areal extent of each unit. These sands, marls and limestones of the Alum Bluff are exposed in the narrow valleys beneath the highest terrace deposits in southwestern Holmes County. The exposures continue down the Choctawhatchee River and Holmes Creek to the vicinity of Norum and Vernon, Washington County, where they are exposed in a series of hills. Vernon (1942, p. 75) mapped the Alum Bluff in the vicinity of Wausau, Washington County, where it had been weathered to deep red clay soils. Vernon (1942, p. 75) noted two additional exposures in Washington County, the Econfina River bed in southeastern Washington County and the silts that are exposed in the high hills in northeastern Washington County. Moore (1955, p. 69-70) suggested the presence of Alum Bluff beds in the hills of southern Jackson County; however, the extent of the Alum Bluff in this area is unknown since it is unmapped. The thickness of the Alum Bluff stage is extremely variable. Vernon (1942, p. 76) reported a maximum thickness of 130 feet in Holmes County which thins to a marine phase 30 feet thick in Washington County. Northward toward central Washington County, the Alum Bluff thickens to 73 feet, and thins to 56 feet in LIMESTONE RESOURCES the vicinity of Falling Water Hill. No accurate mapping is avail- able for southern Jackson County, though Moore (1955, pl. IV) shows the Alum Bluff stage to be approximately 60 feet thick in the vicinity of Round Lake. Vernon (1942, p. 76) reported that the Alum Bluff beds strike northwest and dip 18 feet per mile to the south in Holmes County, and strike northwest and dip about 10 feet per mile in Washington County. The beds strike approximately east-west in Jackson County and probably follow the regional dip of about 12 to 15 feet per mile toward the south. CHOCTAWHATCHEE STAGE "Choctawhatchee Formation" The Choctawhatchee formation (fig. 2) includes all Miocene sediments of post-Alum Bluff age in the Florida Panhandle, Florida Peninsular and their equivalents in the Central and Western Gulf States, as stated by Puri (1959, p. 131). Within these beds Puri. recognized four faunizones in Panhandle Florida, the Area, Yoldia, Cancellaria and Ecphora. In the peninsula, Puri recognized three formations as belonging to the Choctawhatchee stage. The Bone Valley and Alachua formations belong in part to the Choctawhat- chee stage and in part to older stages, and the Tamiami formation was shown by Puri (1959, p. 9) as restricted to the Choctawhatchee stage. Vernon (1942, p. 97) reported that no part of the Choctawhatchee is present in Holmes County and that two facies of the Choctawhatchee were exposed in Washington County. The Area faunizone of this formation is exposed chiefly along the escarpment facing Holmes Creek southward to the junction of Holmes Creek with the Choctawhatchee River. South of the Holmes valley escarpment in Washington County, Vernon (1942, p. 98) reported that the Ecphora-Cancellaria faunizone of the Choctawhatchee is exposed along the steep walls of the narrow stream valleys. Vernon indicated that areas such as the "Deadens" and "Gully Pond Sink" owe their origin to the solution of that limy portion of the Choctawhatchee formation. The Choctawhatchee is unmapped in Jackson County; however, it probably exists in the subsurface in the southern part of the county. Lithologically, the Choctawhatchee includes particles ranging in size from clay to gravel. Vernon (1942, p. 98) noted that in A L A B A M A ----- O of -" 'o' < <- _ m 0 M E sIl I SCRESTVIEW - S A SANTA RosA ASD -NNI'N HIPLE MARIANNA- MILTON SPRINGS : . SI AL 8 E R T Y vPA XAMIJ U 1 C T o INDEX - 4 ," ,-" 1 , INDEX "- -,%'.1 V TOPOGRAPHIC QUADRANGLES , -. F OIODA GEO10GICAL SURVEY Figure 3. LIMESTONE RESOURCES western Washington County the exposures are primarily plastic, being made up of interbedded fossiliferous gravel, saccharoidal limestone, and slightly fossiliferous clays and sands. In eastern Washington County, the formation consists of quartz sand, shell marls, and limestone containing large portions of shell and shell fragments. Vernon (1942, p. 98) found 67 feet of Choctawhatchee present at sec. 16, T. 2 N., R. 15 W., about 31/, miles southwest of Vernon, and about 25 feet exposed along the Econfina Creek in the south- eastern portion of the county. Calculations by Vernon (1942, p. 99) showed the Choctawhat- chee to strike west-northwest with a dip of 8 feet per mile toward the south. POST-MIOCENE SURFICIAL SEDIMENTS Overlying the Miocene sediments in Washington, Holmes and Jackson counties and discounting the unnamed coarse plastics of Alum Bluff stage, are thick deposits of gravels, sands, silts and clays, some of which contain organic remains (fig. 2). The geologic history, terminology, age and interpretations of these de- posits are quite lengthy and the reader is referred to Florida Geological Survey Bulletins 21, 29, 41 and Special Publication 5; also, to the bibliography at the end of this report. In general these deposits are found on the higher hills in the southern part of the three counties, as well as forming a mantle covering almost the entire State of Florida. These deposits in the State range from a few feet in thickness to over 150 feet. These plastic deposits are thought to be of two ages. The higher somewhat better indurated material is thought by Vernon (1942, p. 134) to be of Plio-Pleistocene age, whereas the lower flanking plastics represent deposits formed by Pleistocene and Recent sea level fluctuations. The higher deposits are generally thought of as more typically continental in origin, whereas the lower, younger, flanking deposits are a combination of both alluvial and marine origin. 16 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO LIMESTONE AREAS OF POTENTIAL ECONOMIC IMPORTANCE WASHINGTON COUNTY GENERAL As can be expected in a karst area such as that present in the area of this report, the surface of the limestone beneath the variable thickness of sand and clay mantle is quite irregular. As a general rule the top of the rock conforms to the topographic surface, but departures from this rule are common. Many times a swale on the surface may be reflected and magnified on the top of the limestone in the subsurface, and incipient sinkholes are manifest in this manner. The upper portion of the limestone is generally better indurated along the contact of the mantle rock with the limestone. The thickness and distribution of this indurated upper zone in the limestone will vary greatly and, where it has been observed at the exposure, it varies in thickness from 1 to 5 feet. Since this zone of induration is not regular and does not conform to bedding planes it is quite difficult to determine the thickness. Probably exploratory drilling for aggregate would give only a poor estimate if the holes were not closely spaced. All of the areas, as noted below, fall within Vernon's Suwannee limestone as mapped in 1942. There is probably one exception to the above and that is Loc. WRL-7. Loc. WRL-7 (Area IV) is a roadside exposure (southeast corner NEI/tNEI/. sec. 32, T. 4 N., R. 13 W.) in which the limestone is exposed at an elevation of 160 feet. The limestone exposed at Loc. WRL-7 is lithologically quite similar to the Chattahoochee formation which is exposed on Falling Water Hill (Loc. WRL-1) where the Suwannee-Chattahoochee contact is also at 160 feet. The similarity of the chemical analyses of rock at Loc. WRL-1 and Loc. WRL-7 also indicate that the two samples are from one formation. The Chattahoochee formation at Loc. WRL-1 is primarily a silty, fine grained, chalky to pasty, limestone or calcilutite, whereas Loc. WRL-7 is only a slightly silty fine grained, chalky to pasty, limestone or calcilutite with a local calcirudite facies. Loc. WRL-7 is about 1 mile downdip from Loc. WRL-1. The exposure represents an erosional remnant of Tampa limestone near the southwest flank of Falling Water Hill, where the Chattahoochee is the capping limestone formation. Two generalizations can be made regarding the exposed Suwannee limestone in Areas I through IV (fig. 4, 5): (1) The upper few feet of the highest exposed rock is usually quite dense LIMESTONE RESOURCES and hard. In addition, there is a slightly higher magnesium carbonate content within this zone, as compared to the magnesium carbonate content of the rock lying directly beneath. This more indurated, higher magnesium zone will be seen in cuts along the graded road at Loc. WRL-9 and Loc. WRL-10. The magnesium carbonate content of the rock may also be expected to show an increase on any upper bare horizontal surface within the composite section. Obviously, the above holds true only if the section has not been previously disturbed by earth moving equipment and the like. As in the case of the uppermost portion of the section, the upper zones of lithologic units within the section also show a higher degree of induration than the limestone lying directly beneath them. This zone of more indurated rock is probably due to physical weathering along with chemical weathering and slight recrystallization. The upper portions of these exposures contain up to 9.4 percent magnesium carbonate and, in all probability, may exceed this amount at other locations. The magnesium carbonate is probably secondary; that is, the magnesium was added to the limestone subsequent to its deposition. The samples as collected and chemically analyzed in the report do not lend them- selves to a detailed study of the upper zone magnesium, but a few of the analyses will bear out the trend. Such is the case in the following locations: Loc. WRL-5-1 and 2, where Loc. WRL-5-1 is higher in the section; Loc. WRL-6 through Loc. WRL-6-C, where Loc. WRL-6-C is near the top of the section; Loc. WRL-13-1 through Loc. WRL-13-4, where Loc. WRL-13-2 represents exposed rock near a natural bench and where Loc. WRL-13-4 did not continue to the upper magnesium zone; and Loc. WRL-16-1 and 2, where Loc. WRL-16-2 was near the top of the section. Quarry operators, quarrying the Marianna limestone in Jackson County, also report that the magnesium content increases in the upper part of that limestone. (2) The limestone varies in lithology over short areas. Pure limestone beds of slightly indurated light gray to light cream chalk merge vertically and horizontally to a slightly in- durated to indurated, occasionally slightly iron stained, coquinoid limestone of the same color. In more concise geological terms, the Suwannee generally is a pure fine grained limestone or calcilutite with irregular and regular shaped lenses or pods of granular or calcarenitic limestone, calcarenite, and calcirudite. The lithologies are discontinuous and cannot be traced for any great distance. These individual lithologic units may vary from 3 to 7 feet in thickness and commonly there is a ledge or natural bench developed where there is a vertical change in lithology. Occasionally, nearly 18 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO vertical to somewhat horizontal irregular narrow stringers, lenses, nodules or blebs and otherwise nondescriptive masses of subcrystal- line to dense limestone, occur within the soft granular and coarse carbonate plastic limestone. These better indurated zones of a more dense limestone will pass from one lithology downward to another as if they are the result of the downward percolation or seepage of water, having brought about recrystallization in its path. Deposits of indurated limestones and marls are intermittently exposed along the banks and beds of the Choctawhatchee River and its tributaries from southwest Washington County through Holmes County to the Alabama state line. Loc. WRL-20 (Area V) and Loc. WRL-21 occur along the Choctawhatchee River in Washington County. At Loc. WRL-20, which is the limestone of the Tampa stage, is a calcilutite but not enough exposures of the bed were observed to make a definite lithologic classification. Loc. WRL-21, which is limestone of the Alum Bluff stage, is an isolated exposure of calcarenitic limestone. This exposure probably does not justly represent the formation since the major portion of the rock was covered by younger sands and clays. Loc. WRL-22, which is a portion of the Choctawhatchee occur- ring along the Econfina Creek would be classified as a fine grained calcilutite. The exposure occurs near the water level and is overlain by unsampled sandy shell marl. Currently, feasibility studies being made by State and Federal groups, are underway which will help determine the economic justification for developing the Choctawhatchee River as a main- tained waterway. If developed, the Choctawhatchee could quite adequately serve nearby producers of earth materials with transportation facilities to nearby markets. This potential facility would by no means be limited to only those limestone producers along the river. The more extensive and higher grade limestone (or products thereof) in central Washington County, about 15 miles to the east of the Choctawhatchee River, may also be profitably trucked to the river for shipment to markets along the gulf coast. AREA I Area I (fig. 4) includes a series of exposures of limestone trending in an east-northeast west-southwest direction in north- eastern Washington County. The area is located in the east central portion of sec. 15 and the west central portion of sec. 14, T. 4 N., " ---' .. ,. -" \ e ' .^*t t F .. J/ -. I .. 11 r \. .. - \Iif:.I AI . S / I ="- v . e ^ ...... ..^ -'/ L- 1 0 .. .. Figure 4. Northern one-quarter of the Wausau quadrangle and southern one-quarter of Chipley (luadrangle, showing potential limestone producing Areas I and II, Wash- ington County (See figure 3 for quadrangle index.) 0 P0 P Fiur 4 Nrter oe-uate o te auauqudrnge ndsothrnon-qare of hipey uaranlesho in poentallimstoe pod cin Aras ad I, W sh ingtn Cunt (Se firur 3 or uadrngl inex. TABLE 1. Location Data of Washington County Samples o . 00~ EE e t: o- | | ^ WRL-1 WRL-3 WRL-4 WRL-4-B WRL-4-C WRL-5-1 WRL-5-2 WRL-6 WRL-6-B WRL-6-C WRL-7 WRL-7-2 WRL-7-3 WRL-7-4 WRL-8 WRL-9 WRL-10 WRL-11-B-1 WRL-11 WRL-11-B-2 WRL-11-2-1 WRL-11-2-2 11.5 29 14 14 14 20 20 29.1 29.1 29.1 8.4 10.5 134.6 21 7 3 30 30 30 28 i28 Vertical Slope Vertical Vertical Vertical Slope Slope Vertical Vertical Vertical Slope Vertical Vertical Vertical Vertical Slope SSlope Vertical Slope Vertical Vertical Vertical ow 172 160 158 158 158 102 102 101 101 101 160 158 148 120 56? 167 174 1140 140 140 148 148 160.5 131 144 144 144 82 82 71.9 71.9 71.9 151.6 147.5 113.4 99 160 171 110 110 110 120 120 Channel Spot Spot E Channel Spot Spot SpotChannel Spot Spot Spot SpotChannel Spot SpotChannel Channel Spot SpotChannel Channel Spot Spot Channel Channel Channel Channel Channel 0) - 0 160.5-172 151 146 144-149.8 147 100-101 90 71.9 73.9 101 158-160 156 113.4-134.5 99-110 160 171 110-123.9 123.1-125.1 126.9-133.9 120-129 129-140 5-30+ 2 2 2 1-10 1-10 1-10 1-10 1-10 3-8 3-15 1-8 3-10 3-8 3-8 3-10 S3-10 S3-10 3-10 3-10 0 Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand SSand, clayey sand x Under Aiea V SArea II Area II Area II Area II Area IV Area IV Area IV Area IV Area IV Area III Area III Area III Area III Under Area II Area I Area I Area I Area I Area I Area I Area I TABLE 1. (Continued) cis WRL-11-2-3 WRL-12 WRL-13-1 WRL-13-2 WRL-13-3 WRL-13-4 WRL-14 WRL-15-1 WRL-15-2 WRL-16-1 WRL-16-2 WRL-17-1 WRL-17-2 WRL-18 WRL-19 WRL-20 WRL-21 WRL-22 a -> E 28 Vertical 148 S8.5 Vertical 81 30 Vertical 109 30 Vertical 109 30 Vertical 109 30 Vertical 109 16 Vertical 91 16 Vertical 155 16 Vertical 155 26.7 Vertical 163 26.7 Vertical 163 32 Vertical 117 32 Vertical 117 14 Vertical 99 4 Vertical 110 4 Slope 54 20 3 Vertical 24 11 i 1 '1 Il 1 00 120 CI 72.5 CI 79 Ci 79 CI 79 CI 79 CI 75 CI 139 Sj 139 SC 136.3 S1 136.3 S 85 Cl 85 SI 85 C1 106 j C 50 SI SI 20 SI 5 E > channel 140-148 channel 72.5-76.5 channel 80-82 channel 83.5-85.2 channel 87.5-92.7 channel 98.3-104.3 channel 88-91 pot 146-148 pot 148-149 pot 143-147 pot 147-150 channel 100-102 pot 110 channel 97-99 channel 106-108 pot 52-54 pot :20 pot ;21-24 3-10 i> 0 -10 2-10 2-10 2-10 2-5 0-8 0-8 0-8 4-10 4-10 S2-5 21-4 1-10 S20 10 0 Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand : Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sandy shell marl *4J Area 1 0 Area I Area IV Area IV Area IV Area IV Area II SArea II Area II Area II Area II Area II Area II SArea II Area IV Area IV SArea V Under Area V Under Area V 22 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO R. 13 W. The following locations and sample numbers apply to this area: Loc. WRL-9, Loc. WRL-10, Loc. WRL-11, Loc. WRL-11- B-l, Loc. WRL-11-B-2, Loc. WRL-11-2-1; Loc. WRL-11-2-2 and Loc. WRL-11-2-3 (fig. 4). These sample locations include two roadside exposures and two sinkholes. As can be seen on table 1, the composite thickness of the limestone, from the lowest exposure in the area having an elevation of 110 feet (Loc. WRL-11) to the highest exposure having an elevation of 167 feet (Loc. WRL-10), is 57 feet. The limestone is quite pure, generally having less than 1 percent impurities. A rough estimate of limestone tonnage present in Area I exceeds 3.5 million cubic yards of material. In general, other than perched water and local zones of saturation, the piezometric surface stands at about 55 feet above sea level; thus discounting local zones of saturation, no more than 112 feet of limestone are available at the highest exposed elevation, for a dry mining operation. AREA II Area II (fig. 4) includes a series of rock exposures trending in a northwest-southeast direction in northeastern Washington County. The area is located about one-half mile west of Area I. Area II is located in the southwest corner of sec. 15, T. 4 N., R. 13 W., and in the central southeast corner of sec. 16, T. 4 N., R. 13 W., 3 miles south of the town of Chipley. The following locations and sample numbers apply to this area: Loc. WRL-3, Loc. WRL-4, Loc. WRL-4-b, Loc. WRL-4-C, Loc. WRL-15-1, Loc. WRL-15-2, Loc. WRL-16-1, Loc. WRL-16-2, Loc. WRL-17-1, Loc. WRL-17-2 and Loc. WRL-8, located northwest of Area II. These locations include a roadside exposure on a sink flank, and five sinks. As can be seen on table 1, the composite thickness of the lime- stone from the lowest exposed elevation of 85 feet (Loc. WRL-17-1 and 2) to the highest exposed elevation of 163 feet (Loc. WRL-16-1 and 2) is 78 feet. There, as in Area I, the piezometric surface stands at about 55 feet above sea level; thus, discounting locally saturated zones, there are about 108 feet of limestone at the most which would be available for dry mining. A rough estimate of available limestone in Area II shows the area to contain almost 5 million cubic yards of material. As can be seen on table 2, the limestone is quite pure. Probably more indurated limestone exists in Area II than the other areas as listed under Washington County in table 9. TABLE 2. Chemical Analysis of Washington County Samples n Si' e 0 MaCrc SiO ,' Pe O WRL-1 WRL-3 WRL-4 WRL-4-B WRL-4-C WRL-5-1 WRL-5-2 WRL-6 WRL-6-B WRL-6-C WRL-7 WRL-7-2 WRL-7-3 WRL-7-4 WRL-8 WRL-9 WRL-10 WRL-11-B-1 WRL-11 WRL-11-B-2 WRL-11-2-1 WRL-11-2-2 WRL-11-2-3 WRL-12 WRL-13-1 Samnle Number '/ soluble ', carbonates A1O.., Total: (Reagent, 5%' HCI):3 CaCo, 65.20 100.80 101.50 103.50 102.40 104.00 109.80 107.00 105.20 105.00 92.30 103.30 106.10 102.30 103.50 104.00 104.50 102.70 105.50 102.30 103.00 103.50 105.70 105.50 1.46 Trace Trace Trace Trace 1.25 1.05 Trace Trace 1.25 1.67 Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace Trace 40.95 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 5.45 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 Formation 0.55 0.02 0.02 0.01 0.02 0.01 0.01 0.01 Trace 0.01 0.26 0.01 0.02 Trace 0.01 Trace 0.01 0.01 0.02 0.01 0.02 0.01 Trace 0.01 108.40 101.80 102.50 104.49 103.45 106.28 111.86 107.99 106.19 107.25 100.00 104.31 107.13 103.33 104.47 104.96 105.47 103.68 106.53 103.31 104.03 104.51 106.68 106.51 49.98 99.89 99.59 99.66 98.69 99.63 99.81 99.76 99.85 99.86 85.05 99.40 99.59 99.37 99.82 99.93 99.82 99.67 99.42 99.29 99.60 99.71 99.52 99.84 Chattahoochee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Chattahoochee Suwannee Suwannee Suwannee Crystal River Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee TABLE 2. (Continued) % soluble ', '4/ ',, '/ carbonates CaCo. MgCo,: SiO., Fe.,O, AI..O: Total' (Reagent, 5'/, HCI)- Sample Number WRL-13-2 WRL-13-3 WRL-13-4 WRL-14 WRL-15-1 WRL-15-2 WRL-16-1 WRL-16-2 WRL-17-1 WRL-17-2 WRL-18 WRL-19 WRL-20 WRL-21 WRL-22 1.25 Trace Trace Trace Trace Trace Trace 1.46( Trace Trace Trace Trace Trace 1.67 1.67 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 0.92 10.25 0.92 0.01 Trace 0.01 Trace 0.01 0.01 0.02 0.03 Trace 0.03 Trace Trace 0.01 0.14 0.08 109.68 104.30 105.31 111.11 102.48 103.38 102.81 105.67 107.8!) 107.19 107.30 104.78 103.08 102.44 102.87 99.59 99.73 99.65 99.77 99.82 97.90 99.81 99.6(6 99.48 99.77 99.75 8(;.51 97.5.8 Formation Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Suwannee Tampa stage Alum Bluff stage "Choctawhatchee" 'Where the silicon dioxide content of the samples is 0.92'/ the percentage represents an average SiO- content for the samples falling in the 98'/ to 110'/ calcium carbonate range. This average figure was derived from actual silicon dioxide analyses of selected samples falling within this 98'/ to 110% range. :This total is the sum of the percentages of the individual chemical components of the sample. These percentages have not been converted mathematically to a basis of 100'/ since this could introduce an error into the analysis. To convert sample component percentages to a basis of 100: (divide) sample component percentages x 100 percent total ::A separate analysis, in which the insoluble fraction includes other insolubles in addition to silicon dioxide. 107.40 103.30 104.30 110.10 101.50 102.40 101.80 103.20 106.80 106.00 106.30 103.80 102.10 89.80 99.60 LIMESTONE RESOURCES AREA III Area III trends in an east-west direction in northeastern Wash- ington County, and is located in the northeastern portion of sec. 32 and in the northwestern portion of sec. 33, T. 4 N., R. 13 W., 5.2 miles south of the town of Chipley. The following locations and samples apply to the area: Loc. WRL-7, Loc. WRL-7-2, Loc. WRL- 7-3, and Loc. WRL-7-4 (fig. 5). These locations include one road- side exposure and three sinks. The composite thickness of limestone as exposed in the area from the lowest exposed elevation of 99 feet (Loc. WRL-7-4) to the highest exposed elevation of 160 feet (Loc. WRL-7) is 61 feet. With the exception of Loc. WRL-7, which is a roadside exposure of the Chattahoochee formation, the limestone is quite pure as are the exposures in the other areas of Washington County (table 2). A rough estimate of limestone available in Area III exceeds 3 million cubic yards. Indurated zones of limestone are present in all four localities; however, it is of limited amount, generally occurring in the upper 6 to 10 feet of exposure. The piezometric surface here stands at approximately 55 feet, and discounting local perched water and inflow into the sinks, there is a probable maximum of 105 feet of limestone available for dry mining. AREA IV Area IV (fig. 5) is a discontinuous group of exposures trending in a northeast-southwest direction in the northeastern part of the county. They are located in the central and southwestern part of sec. 36, and the southeastern portion of sec. 35, T. 4 N., R. 14 V. The area also includes the northwestern portion of sec. 1, T. 3 N., R. 14 W. The following locations and samples refer to Area IV: Loc. WRL-5-1, Loc. WRL-5-2, Loc. WRL-6, Loc. WRL-6-B, Loc. WRL-6-C, Loc WRL-12, Loc. WRL-13-1, Loc. WRL-13-2, Loc. WRL-13-3, Loc. WRL-13-4, Loc. WRL-14, Loc. WRL-18, and Loc. WRL-19 (fig. 5). Other than one roadside exposure, these locations in Area IV are sink exposures. One unsampled location is an exposure in the north-south graded road, which is somewhat along the axis of the grouping of localities. This rock is well indurated and it is the highest exposed in Area IV (elevation 128 feet). The lowest elevation of exposed rock is at Loc. WRL-6, where the limestone occurs at 71.9 feet (table 1). Thus the maximum apparent thick- ness of limestone is 56.1 feet. The rock in Area IV is quite pure AREA~ i '-- .J * I / ;wR Wf- j;- I~s 1~~. 1,K ,i~C7 I\- J WRLf SC.A.I 24W' C I i C ~~"c Figure 5. Northern one-half of Wausau quadrangle showing potential limestone pro- ducing Areas III and IV, Washington County. (See figure 3 for quadrangle index.) r r O o r ,4 cl 31 LIMESTONE RESOURCES as is the limestone of the other areas in Washington County (table 2). The amount of limestone available for mining in Area IV will probably exceed 11 million cubic yards. The piezometric surface in Area IV stands roughly at 50 feet above sea level. Thus, discounting localized zones of saturation as well as a small amount of surface discharge into the area, there should be a maximum of about 78 feet of limestone available for dry mining above the piezometric surface. AREA V Area V (fig. 6) is located along the east bank of the Chocta- whatchee River flood plain. The area is confined to the escarp- ment which forms the boundary between the flood plain on the west and the dissected highlands to the east. Yates Mill Creek flows southwestward along the foot of this escarpment on its way to its point of juncture with the Choctawhatchee River. Area V trends in a north-northeast and south-southwest direction and extends from the NEI/&. sec. 17, T. 3 N., R. 16 W., to the SEI/ sec. 8, T. 3 N., R. 16 W. Vernon (1942) maps the limestone of the Tampa stage as occurring along this escarpment and projects this formation well beyond the north-south limits of the area. He projected the Tampa formation (Tampa stage) from sec. 8 of Area V northward through sec. 9 and also projected the formation from sec. 17 of Area V southward well into sec. 20. These ex- tremities were not included in Area V since they were unvisited by the author. Vernon (1942, p. 71, 72) described three localities in Area V, localities W-3, W-4, and W-5. Loc. WRL-20 (fig. 6; tables 1, 2) is a 4-foot stratum of indurated high grade limestone lying near Vernon's locality W-4. Less well indurated beds of sandy fossiliferous limestone lay above and below this better indurated zone. The limestone in Area V forms a natural bench at an elevation of 50 to 54 feet above sea level. This bench is perhaps the result of erosion connected with high stands of the Choctawhatchee River coupled with the resistance of the limestone to erosion. Case- hardened and solution-pitted boulders occur along the flanks of the exposure from the crest of the bench to Yates Mill Creek. The thickness of the exposed rock is between 15 and 18 feet. For the most part the exposures are covered with varying thicknesses of sandy clay and organic material, which in the zone 28 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO Figure 6. West-central portion of Hinson Crossroads quadrangle showing potential limestone producing Area V, Washington County. (See figure 3 for quadrangle index.) of potential mining may at the most reach 10 feet in thickness. A conservative estimate of limestone available in Area V exceeds 0.5 million cubic yards. In general, past mining of this type of deposit has been by dry methods; however, procedures utilizing floating dredges or drag- lines may prove advantageous in coping with problems located so near the ground-water levels and the Choctawhatchee River. The proximity of the Choctawhatchee River which is less than 0.5 miles westward makes the area quite attractive for barge transport. LIMESTONE RESOURCES -- t - 7 - OXlp.- 406 d A; o 4p -r Z. & 4p. 4 40 4o- 440. I A 411 'I e 46 -dw4 Vs SCALE 1 24000 ii V ,,% A4 1 \\~\ Its 4k.) AL3Z2\4 wJ \! ZI t \S, ,Ok: 0 0 Iu .. Figure 7. Southeastern portion of the Redbay quadrangle showing sample location WRL-21, Washington County. (See figure 3 for quadrangle index.) 29 30 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO OTHER LOCATIONS Other exposures occur south of Area V along the Choctawhat- chee River banks and in the stream bed. One such location (Loc. WRL-21) at Spears Fish Camp, on the east side of the river in the NEI/ESEI/' sec. 31, T. 2 N., R. 16 W. (fig. 7), exposes at the water level a 1-foot ledge of sandy fossiliferous limestone having over 87 percent calcium carbonate. The exposure is overlain by a {^J A v^ 0 N 4- \ I 1 Figure 8. Northeastern portion of the Bennett quadrangle showing sample location WRL-22, Washington County. (See figure 3 for quadrangle index.) LIMESTONE RESOURCES few feet of sandy clayey shell marl. The deposit was placed by Ver- non (1942) in the Alum Bluff group (table 1), and would now fall in the Alum Bluff stage of Puri, (1953b). Indurated limestone also is exposed at water level at Jenkins Fish Camp, on the east side of the river, in the northwest corner of the SW'/4 sec. 18, T. 2 N., R. 16 W. (fig. 7). In all probability many additional exposures of rock, such as the two above and those of Area V, occur along the Choctawhatchee River and along its tributaries from southwest Washington County upstream through Holmes County to the Alabama state line, but because these were relatively inaccessible they were not studied. Rocks that can be mined along the river should be carefully considered since they can be favorably exploited by use of draglines and dredges and transported by barge to the consumer. Indurated limestone and marl deposits occur in the southern portion of Washington County along the Econfina Creek. These deposits are exposed intermittently from Walsingham Bridge in the SW1/ sec. 15, T. 1 N., R. 13 W., south into Bay County. Three feet of indurated limestone is exposed at Loc. WRL-22 (fig. 8), overlain by 10 feet of sandy shell marl. The indurated rock con- tains over 96 percent calcium carbonate along with 1 to 2 percent magnesium carbonate (tables 1, 2). If a market for shell marl is established, along with markets for the more indurated limestone, regions adjacent to the Econfina Creek, where the overburden is negligible, would offer some hope of economic development. The presence of water, within 13 feet of the ground surface, may make a dragline or floating barge mining operations practical. Loc. WRL-1 (Falling Water, fig. 5) was mainly established for lithologic control and the rock could not be mined, since the area is dedicated to recreation. HOLMES COUNTY GENERAL Limestone exposures are rare in Holmes County as compared to those in Washington and Jackson counties. Only a few well developed sinks expose rock faces. Additional exposures were noted by Vernon (1942) but many of these could not be reoccupied. The observation regarding enriched zones and general karst charac- teristics as discussed under the general heading of Washington County area applies also to the Holmes County limestones. Area I (fig. 9) lies in the area mapped as Marianna limestone NI- I- (I>- " ". I -u -.I ........ ,,,-a :- \ l' l oh -( .W - 2z No t Figure 9. Northeastern portion of the Prosperity quadrangle showing potential lime- stone produeinl. Area I and sample location HRL-7, Holmes County. (See figure 3 for quadrangle index.) LIMESTONE RESOURCES by Vernon in 1942. There is a possibility, as Vernon (1942, p. 55) pointed out, that the upper limestone part of Area I may be Byram marl. Color and chemical evidence suggests that these rocks differ from that exposed at Marianna. The Crystal River formation, as exposed at Loc. HRL-1, is a pure calcarenitic limestone, but beds or lenses of calcilutite or calcirudite probably are present both laterally and at depth. The Marianna as exposed at Loc. HRL-2, is a well indurated calcilutite, whereas at Loc. HRL-3 and Loc. HRL-3-2 the Marianna is poorly indurated to indurated calcilutite along with occasional lenses of poorly indurated to indurated calcarenitic limestone. Undoubtedly large reserves of limestone are present in Holmes County but these will probably have to be proved by test drilling. (See Vernon, 1942.) Many deposits of rock are known to occur along the Chocta- whatchee River and its tributaries. One such deposit, Loc. HRL-1, along Wrights Creek exposes high grade limestone a few feet above water level (fig. 10). Vernon, 1942, mapped many Ocala limestone deposits masked by a thin veneer of surficial sediments along Wrights Creek in central Holmes County and along Pittman Creek in north-central Holmes County. Additional deposits occur along the Choctawhatchee River from the Alabama line southward for 2.5 miles. These deposits could be mined by dragline or floating dredge and transported by means of the Choctawhatchee River to markets along the gulf coast. As noted before, under Washington County, feasibility studies are currently under way by State and Federal authorities which may prove the Choctawhatchee River to be of sufficient value as a waterway to justify the cost of improving and maintaining a channel into Alabama. If the cost- benefit ratio justifies such a channel, an inexpensive waterway will be provided, and rock in the Choctawhatchee watershed would have a greater mining potential. AREA I Area 1 (fig. 9) includes a group of locations that trend in a northwest-southeast direction in the west-central part of Holmes County. The area is located in the El/. sec. 3, T. 4 N., R. 17 W. The following locations and samples apply to this area: Loc. HRL- 2, Loc. HRL-3-1, Loc. HRL-3-2. The rock is exposed in two sink- holes. The composite exposure, from the lowest exposed elevation of 97 feet (Loc. HRL-2) to the highest elevation of 148 feet Ir*r l- -- . p r4 .N HRL-1 and north-central portion of Ponce de Leon quadrangle showing sample location HRL-4, Holmes County. (See figure 3 for quadrangle index.) TABLE 3. Location Data of Holmes County Samples 0 r_ g: e *-g o ^ a -.- .. S EE 0. 4 go =>' i W. w 0 &0) > ; E- 04, Ea M C0 P w* U-2 C i0m oo 0 b< 1? aI a s! 1 Slope 4 Vertical !8 Vertical 18 Vertical Ponce de Leon Springs Water eleva- tion 48 Morrison Spring Water eleva- tion 30 Blue Spring Water eleva- tion 74 1 Slope Spot Spot Channel Channel 81-82 98 120-125.7 131-140 2 4-15 2-12 2-12 Sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Under Area 1 Area I Area I Area I Under Area I Under Area I Under Area I 127 127 Spot 127 2-15 Sand, clayey sand HRL-1 HRL-2 HRL-3-1 HRL-3-2 HRL-4 HRL-5 HRL-6( HRL-7 Under Area I TABLE 4. Chemical Analysis of Holmes County Samples % soluble Sample % % carbonates Number CaCo: MgCo, SiO.,' Fe..O: Al.,O, Total' (Reagent, 5%/ HCI): Formation HRL-1 98.50 1.67 0.92 0.50 0.14 101.73 97.71 Crystal River HRL-2 99.30 1.67 0.92 0.25 0.08 102.22 99.46 Marianna 0 HRL-3-1 101.50 1.26 0.92 0.09 0.01 103.78 99.33 Marianna o HRL-3-2 101.80 Trace 0.92 0.14 0.04 102.90 99.35 Marianna HRL-4 No Samples Tampa stage HRL-5 (Walton County) No Samples Tampa stage HRL-6 No Samples Tampa stage HRL-7 No Samples Suwannee iThis percentage represents an average SiO., content for the samples falling in the 98% to 110% calcium carbonate range. This average figure was derived from actual silicon dioxide analyses of selected samples falling within this 98% to 110%' range. The above also holds true for all samples whose silicon dioxide content is shown as 3.30%', with the exception that C this average figure was derived from actual analyses of selected samples falling within the 95.0% to 96.5% calcium car- bonate range. 'This total is the sum of the percentages of the individual chemical components of the sample. These percentages have ' not been converted mathematically to a basis of 100% since this could introduce an error into the analysis. To convert Z sample component percentages to a basis of 100: (divide) sample component percentages x 100 percent total 0 :'A separate analysis, in which the insoluble fraction includes other insolubles in addition to silicon dioxide. o LIMESTONE RESOURCES (Loc. HRL-3-2 is 51 feet). The limestone is quite pure having only slightly less purity than the Washington County limestone (tables 3 and 4). An estimate of the limestone reserves available in Area I exceeds 1.5 million cubic yards. As in all of the areas before, water problems encountered above the piezometric surface will be those caused by perched water zones, local zones of saturation, or surface discharge into the area. The piezometric surface stands roughly at 90 feet, thus there should be at least 58 feet of limestone available for a dry mining operation. OTHER LOCATIONS The remaining locations in Holmes County are not mentioned within an area description for specific reasons, as will be seen. Loc. HRL-1, about 6 miles north of Bonifay in the SWI/INEI/ sec. 1, T. 5 N., R. 15 W., occurs just above ground level near Wrights Creek (fig. 10). The limestone is rather poorly indurated and exceeds 98 percent in calcium carbonate percentage. The exposure is located alongside the above creek and could easily be mined by dredging (fig. 10). A rough estimate of limestone available at Loc. HRL-1 exceeds 0.5 million cubic yards. Loc. HRL-4 is Ponce de Leon Springs and is used as a reference point to obtain the elevation of the limestone in that part of Holmes County (fig. 10). Loc. HRL-5 (Morrison Spring, fig. 11), which is slightly over 3 miles south of Holmes County in Walton County, and Loc. HRL-6 (Blue Springs, fig. 11) were used to determine the elevation of the top of the limestone, in that particular part of the county. Loc. HRL-7 (fig. 9) which is a double sink located slightly over 1.5 miles south-southwest of Loc. HRL-3-1 exposes a few boulders of limestone in its bottom. Limestone would probably be encountered a few feet below the bottom of this broad sink. The piezometric surface at Loc. HRL-7 stands at about 90 feet as it does at Loc. HRL-3-1. Therefore, approximately 37 feet of dry mining is available since the top of the limestone would be en- countered at about 127 feet above sea level. JACKSON COUNTY GENERAL Deposits of limestone are quite abundant in Jackson County. The area descriptions of this report do not attempt to include all of the exposures in the county, but merely give the details of the S .. .. . .." S13 00 - I \ . c 2' 0- . - . -* - - I - 254 Figure 11. Southeastern portion of Ponce de Leon quadrangle showing sample loca- tion HRL-5, Walton County, and south-central portion of Prosperity quadrangle showing sample location HRL-6, Holmes County. (See figure 3 for quadrangle index.) '1I c0 rl8 r IL Fiur 1. ouheser prtonofPoc d Lonqudrngeshwig amleloa tinHL5 ato ony n suhcnrlpoto fPopeiyqarnl shwn apelctinHL6 omsCuny Sefgr orqarnl ne. - ,!.\ ., ,. -' ' .. , ,. n,'I c i' i. LIMESTONE RESOURCES more obvious occurrences. Undoubtedly many exposures can be seen outside the areas as outlined on figures 12, 13, 14, 15, 16, and 20, and it is hoped that the descriptions of the outlined areas will point toward additional locations which may prove to be of economic value. Though deposits of limestone are abundant in this county, there are currently only two producers. The Marjax Company and the West Florida Lime Company. The Marjax Company quarry is located a few miles northwest of Marianna in the SWt sec. 30, T. 5 N., R. 10 W., and the West Florida Lime Company is mining about 1 mile north of Cottondale in sec. 30, T. 5 N., R. 11 W. Both producers mine from the Marianna limestone and market their product primarily for agricultural purposes. The Crystal River formation, the Marianna limestone, the Suwannee limestone, and sediments of the Tampa stage are exposed in northern Jackson County. Of these, the Crystal River limestone and the Marianna limestone are the purest chemically and most widely exposed. Where the plane of dip of these formations rises toward the surface in northern Jackson County, solution of the limestone has reduced the land surface to a broad lowland. This lowland is part of a larger physiographic feature named by Cooke (1939) which extends westward into the Chipley area. The exposed and buried limestone surface within this basin is highly irregular. Along the northward facing escarpment at the southern border of the lowland, the local relief of the exposed lime- stone exceeds 70 feet. The local relief of the limestone surface beneath the soil mantle within the basin itself is perhaps as great as along the southern border of the lowland; however, no informa- tion is available to bear this out. The red sand-silt-clay mantle covering the limestone surface within the basin represents in part the insoluble residue of the eroded limestone and now fills the low spots on the uneven limestone surface. This plastic mantle did not necessarily form in place, but has been transported and redeposited by local stream action. This broad solution basin has many characteristics of a large uvala which is a large sink area formed by the coalescence of many sinks. Solution irregularities in the limestone are also sometimes filled by a dark organic clay which form lenticular and vertical pockets. The lenticular pockets have been observed in the Marianna limestone to be 20 or 30 feet long and 3 or 4 feet thick. The vertical pockets may be on the order of 3 or 4 feet in diameter and may exceed 20 or 30 feet into the limestone. These clay pockets are one of the problems of mining and they must be either mined around or removed, TABLE 5. Location Data of Jackson County Samples JRL JRL JRL JRL > - 0 E 22 C 0 -1 2.5 Vertical 161 4-1-2 5.4 Slope 159.1 -2 3 Vertical 109 -3-1 15 Vertical 105 JRL-3-2 JRL-4 JRL-5 JRL-6 JRL-7 JRL-8 JRL-9 JRL-10 JRL-11 JRL-12 JRL-13 JRL-14 JRL-15 Vertical Vertical Vertical Vertical Slope Slope Slope Vertical Vertical Slope Vertical Vertical Slope 108 135 136 163 159 131 158 100 108 142 122 48.8 133 10 159.5 153.8 106 90 105 130 106 162 150 89 145 96 96 140 117 44.8 132 ac Spot Spot Spot Spot Spot Channel Composite section Spot Spot Spot Spot Channel Spot Spot Channel Spot Spot 0 cc 159.5-160.5 153.8 107 90, 92, 96, 98, 100 106, 108 130-134 10(-136 162-163 150-152 115, 118-121 153-154 96-100 96-97, 99-100 100-101 141 117-122 17.8-48.8 132-133 2-4 2-4 1-4 3-8 0-5 1-8 S0 Sand, clayey sand Sand, clayey sand Sand, clayey sandl Sand, clayey sand Sand, clayey sand Sand, clayey sand 3-4 Sand, clayey sand 2-4 Sand, clayey sand 3-8 Sand, clayey sand 4-10 Dolostone, clayey sand and sand 14 Sand, clayey sand 2-6 Sand, clayey sand 3 Sand, clayey sand 8-12 Sand, clayey sand 4 Sand, clayey sand 6 ; Sand Area V Area V Area I Area II Area II Area IV Area IV Area III Area III Area III Area III Area II Area II Area VII Area VII Under Area VII Under Area VII TABLE 5. (Continued) 3.- 'a 0-S *l-. -2 0; g2 'Se a-< ^ 22 C wd 4. 0. co cc 0 O E1E >l >1 ! cP1 4) E~i 0E ~ m W JRL-16 JRL-17 JRL-18-1 JRL-18-2 JRL-19 JRL-20 JRL-21-A JRL-21-B JRL-22 JRL-23 JRL-24 JRL-25 JRL-26-1 JRL-26-2 JRL-27 JRL-28 JRL-29 JRL-30 JRL-31 JRL-32 JRL-33 * Vertical Slope SVertical Vertical Vertical Slope SVertical Vertical Vertical Slope Vertical Vertical Vertical Vertical Vertical Vertical Vertical Vertical Vertical S143 149.3 142 142 103 103 161 161 125 z -P 4) > X~ >a .P u o a* ao ss 1 Z4 n-a -r Composite 123-143 section Channel Spot Channel Spot Channel Channel Channel Channel Channel Channel Channel S128-136 82-103 84-86 139.5-158 112.4-119 120-125 117-125.5 105-107 120-122 106-108 4 0-12 2-10 2-10 1-5 4-10 2-6 2-6 2-15+ 2-3 2-5 2-5 2-8 15+ 1-10 1-10 1-10 1-12 1-12 -p: e 0 Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand Sand, clayey sand -a Area V Area V Area VI Area VI Under Area II Area II Area IV Area IV Area VIII Area V Area VIII Area VI Area VI Area VI Area VI Area V Area IV Area VII Area VII Area VII Area VII 42 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO since the presence of clay in limestone is very undesirable for many commercial uses. The thickness of the sand and clay mantle of the younger formations lying above the limestone is quite variable, but on a large scale the irregular topographic surface conforms to the surface of the underlying limestone. This is especially true where the Crystal River and Marianna limestone are near the surface. In the relatively more plastic facies of the Suwannee limestone and Tampa stage sediments, the topographic surface of the over- lying sand and clay mantle conforms to the buried formation surface only where the formation is calcareous. This degree of conformity between the topographic surface and the underlying formation is ultimately the result of the solution of the underlying soluble limestone. At some exposures the Marianna limestone is overlain by a poorly indurated to indurated, fissile to blocky shale. In some instances, this bed is an indurated dolomitic limestone. Puri and Vernon (1961) placed these beds in the Byram formation and believed that the Bucatunna clay may be represented by the clay or shale beds. However, MacNeil (1944, p. 1341) stated that "eastern Holmes, northern Washington and western Jackson counties, Florida, is an area of pre-Chickasawhay erosion" and Marsh (1960, personal communication) felt that "MacNeil implied that there the Chickasawhay equivalent rests upon the marl member of the Byram, the Bucatunna having been removed by erosion." Moore (1955, p. 51) apparently included these sediments in the Suwannee limestone as he defined and mapped the formation (pl. I). The Byram sediments and possibly some recrystallized Marianna sediment may be observed at the following localities: Loc. JRL-3-3, Loc. JRL-7, Loc. JRL-8, Loc. JRL-9, Loc. JRL-10, Loc. JRL-11, and Loc. JRL-28. Large production of high purity rock is available from the Crystal River formation and the Marianna limestone. Each varies very little chemically and lithologically between exposures. Table 6 indicates that the Crystal River formation is quite pure chemically, and that the Marianna limestone follows closely, being only a few percent lower in calcium carbonate. The Suwannee limestone generally is more argillaceous and more arenaceous than the Crystal River formation and Marianna limestone, but less argillaceous and arenaceous than the younger sediments of the TABLE 6. Chemical Analysis of Jackson County Samples CaCo M'g, Si CaCo, MgCo:: SiO.,' Fe,O,0 'i soluble 'h 1/ carbonates Al.,O:, Total' (Reagent, 5'/ HCI):1 1.67 2.35 1.88 1.88 37.20 2.09 1.88 34.20 2.09 2.09 JRL-1 JRL-1-2 JRL-2 JRL-3-1 JRL-3-2 JRL-4 JRL-5 JRL-6, JRL-7 JRL-8 JRL-9 JRL-10 JRL-11 JRL-12 JRL-13 JRL-14 JRL-15 JRL-16 JRL-17 JRL-18-1 JRL-18-2 JRL-19 0.28 100.91 0.20 102.49 0.01 105.77 0.07 101.18 0.49 100.77 0.28 102.17 0.28 102.42 0.55 100.41 95.30 98.80 102.80 95.80 5(i.00 98.50 96.50 55.50 96.30 98.6;0 101.10 95.30 46.50 25.00 57.50 53.80 95.00 102.10 103.10 97.80 Trace 0.92 2.34 3.30 35.30 16.75 15.80 55.25 35.70 6.88 40.60 9.95 1.88 3.30 No analysis 1.05 Trace 2.09 0.92 0.12 0.92 0.08 0.92 0.31 0.22 102.38 0.08 101.21 0.15 99.31 0.73 97.41 0.03 100.57 0.25 104.95 0.25 100.86; 0.03 104.22 0.01 104.01 0.11 101.23 96.89 97.44 98.10 96.79 85.52 97.49 95.72 75.38 97.81 97.91 97.84 97.28 79.63 34.27 89.88 89.87 95.97 99.35 99.60 97.88 Suwannee Mal ianna Mai ianna Marianna Byram/ Suwannee Marianna Marianna Byram/ Suwannee Marianna Marianna Byram/ Suwannee Marianna Marianna Chattahoochee Chattahoochee Suwannee Tampa stage Marianna Marianna Crystal River Crystal River Marianna Sample Number Formation 0.92 0.38 3.30 0.46; 9.75 0.41 3.30 0.13 0.09 101.91 0.92 0.30 0.21 102.12 No analysis but similar to Loc. JRL-6 ~ TABLE 6. Chemical Analysis of Jackson County Samples soluble Sample ', ', '/ carbonates Number C(aCo MgCo SiO.' Fe.,O AI..O Total" (Reagent, 5' HCl) Formation ft- JRL-20 99.60 1.46 0.92 0.27 0.16 102.41 98.09, Marianna JRL-21-A 100.70 1.77 0.92 0.25 0.15 103.79 97.24 Marianna JRL-21-B 101.20 1.19 0.92 0.28 0.10 103.69 96.86 Crystal River JRL-22 96.30 2.09 3.30 0.20 0.16 102.05 95.46 Marianna 0 JRL-23 No analysis Marianna JRL-24 No analysis Marianna JRL-25 99.80 1.46 0.92 0.11 0.03 102.32 99.25 Crystal River JRL-26-1 101.30 Trace 0.92 0.12 0.04 102.38 99.29 Crystal River JRL-26-2 101.30 1.05 0.92 0.11 0.03 103.41 99.35 Crystal River JRL-27 102.3 Trace 0.92 0.09 0.01 103.32 99.53 Crystal River JRL-28 No analysis Marianna : JRL-29 Similar to Area V analysis Crystal River/ t Marianna JRL-30 No analysis; similar to Loc. JRL-12 Chattahoochee JRL-31 No analysis; similar to Loc. JRL-12 and 13 Chattahoochee JRL-32 No analysis Chattahoochee JRL-33 No analysis; similar to Loc. JRL-12 and 13 Chattahoochee 'Where the silicon dioxide content of the samples is 0.92', the percentage represents an average SiO., content for the sam- 1j ples falling in the 98'/ to 110'` calcium carbonate range. This average figure was derived from actual silicon dioxide analy- g ses of selected samples falling within this 98% to 110% range. The above also holds true for all samples whose silicon dioxide content is shown as 3.307 with the exception that this average figure was derived from actual analyses of selected samples falling within the 95.0% to 96.5%r/ calcium carbonate E range. 0 -This total is the sum of the percentages of the individual chemical components of the sample. These percentages have not been converted mathematically to a basis of 100'/ since this could introduce an error into the analysis. To convert sample component percentages to a basis of 100: (divide) sample component percentages x 100 percent total :A separate analysis, in which the insoluble fraction includes other insolubles in addition to silicon dioxide. LIMESTONE RESOURCES Tampa stage. The Suwannee limestone is exposed over much of central Jackson County, but exposures are limited. (See Moore, 1955, pl. I.) No tonnage estimates were made of the Jackson County deposits because of the large extent of the areas as delimited by this report. Millions of tons are present in the larger areas and it is felt that even the smallest areas when prospected will show over a million tons present. Lithologically, the Crystal River formation and the Marianna limestone are distinguishable, whereas facies of the Tampa stage are sometimes quite similar to that of the Suwannee limestone. For the most part the Crystal River limestone is a white to cream colored, chalky, soft to locally indurated fossiliferous coquinoid limestone. More concisely, this formation would be considered as having three lithologic types: calcilutite, calcarenite, and an inter- mediate calcarenitic unit. Each rock unit can be expected to grade laterally and vertically into other lithologies. Local small hard lenses and nodules of finely crystalline to dense limestone occur randomly throughout the exposures. The Marianna limestone is a slightly darker cream colored fossiliferous chalky equigrained, soft to slightly indurated limestone, containing a small percentage of arenaceous insolubles and a small percentage of magnesium carbonate. It would be considered generally as varying from a calcilutite to calcarenite. As in the Crystal River formation, local small hard lenses and nodules of finely crystalline to dense limestone occur randomly throughout the exposures of the Marianna limestone. Moore (1955, p. 51) described the Suwannee limestone as tan to buff colored limestones, dolomitic limestones, and calcareous clays. He (Moore, 1955, p. 59) described the Tampa formation as a white, gray and green clay which is frequently calcareous. In the southeastern part of the county the Chattahoo- chee formation of the Tampa stage occurs as a white arenaceous argillaceous limestone. To slightly rephrase the above description, one may say that the Suwannee varies from a tan to buff limestone, to a dolomitic limestone, and to a calcareous clay, whereas the Tampa formation varies from a sandy clayey limestone, to a calcareous white, gray and .green clay. The dolomitic character is not restricted to the Suwannee limestone however. At Loc. JRL-12, Loc. JRL-13 and Loc. JRL-15, the latter two of which are lime- stone exposures of the Tampa as described by Moore (Loc. JRL-13 is Moore's J-111, and Loc. JRL-15 is Moore's J-131), the magnesium carbonate percentage reached as high as 40 percent of the analysis. It thus appears that the final distinguishing lithologic 46 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO difference between the limestone facies of the two formations involves color and texture. Generally, the younger Tampa sediments are devoid of tan to buff colors and is more argillaceous and arenaceous than the Suwannee limestone. This relationship would only be true in this immediate area since lateral lithologic change can be expected in each formation. AREA I Area I (fig. 12) includes a group of exposures noted on the northern shore of Merritts Mill Pond and along State Highway 164. These exposures extend from the NEI/NEI/.t sec. 6, T. 4 N., R. 9 W., northeastward through the central and southern portion of sec. 32, T. 5 N., R. 9 W., and into the western portion of sec. 33, T. 5 N., R. 9 W. Two limestone formations are apparent in the area, contact of the formation in the road cut at the western side of the SEI/tNW/1. sec. 32, T. 5 N., R. 9 W. Here the contact elevation is 127 feet. A short distance westward from this point, an indurated layer of Suwannee limestone may be observed on the north side of the road right-of-way. The underlying Marianna limestone may be seen at various locations eastward from the above mentioned points to the center of sec. 33, T. 5 N., R. 9 W. Eastward and southeastward from this latter point numerous small sinkholes can be seen within and on the flanks of the larger, partially filled and cultivated sinks. From the above mentioned Marianna-Suwannee limestone contact, eastward along State Highway 164 to the center of sec. 33, T. 5 N., R. 9 W., the elevations on the top of the exposed limestone vary as follows: 127 109 114 100 118 feet above sea level. This attests to the uneven surface of the exposed rock. The Marianna limestone forms some of the topographic lobes that extend southward to the edge of Merritts Mill Pond where rock is exposed above the water level at an elevation of about 80 feet. The top of the Marianna along a line extending from the NEI/t sec. 6, T. 4 N., R. 9 W., to the SEIt sec. 32, T. 5 N., R. 9 W., on these same lobes stands between 98 and 102 feet above sea level. Though the area was not visited, in all probability the topographic lobes on the southeast shore of Merritts Mill Pond across the pond from the above discussed lobes should expose the top of the Marianna limestone at about the 100-foot contour. Thus in Area I there is a maximum of about 47 feet of Marianna limestone above the level of Merritts Mill Pond and Blue Spring. Moore (1955, pl. I) also extended the Suwannee and Tampa (Tampa stage) ! \ 'n #o. , .. O I)\ .." *, - ?00 I f .m . 00 ~ 29 000000 poui At .- JRL- "figure w fr u a l ine .).0 4k I %. : ,. ,\, I .13 IL.31 33 ;y, ,_.. .... W. 0. 4 Ir IV ... t: ;-i,4,- N 0n .. 46> 4 tJ ,1.0 Id P~O ~3 i . .. ,, ,'% Fgr 1. S n o figure 3 .or q a index.) producin Areas and II and saple locaion JRL19, Jacson Couty. (Se figure 3 for quadrangle index.) 48 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO formations into this area. The Suwannee is represented by indurated rock as present southeastward from sec. 33, T. 4 N., R. 9 W., on the road to Grand Ridge where a few exposures of the Suwannee limestone may be seen. One such exposure in a sink located in the SEI/tNEIi sec. 11, T. 4 N., R. 9 W., adjacent to the road on the north side, is typical. It is anticipated that the greatest amount of indurated rock will be found within the Suwannee exposure. Loc. JRL-2 is in Area I (fig. 12). The Marianna limestone is quite pure, having a minor percentage of magnesium carbonate and quartz (tables 5, 6). The piezometric surface stands at about 90 feet in this area, which is somewhat above the level of the water at Blue Spring. This could be expected since a cone of depression is formed around the springhead. As mentioned earlier, there are 47 feet of Marianna limestone above the level of Blue Spring. Since, potentially, the piezometric surface may stand 10 feet higher away from the spring, the amount of available limestone for mining is about 37 feet. However, if there are no fissures in the quarry area mining may be carried somewhat deeper until water under artesian pressure is encountered. Even so, this deeper mining would seem hazardous, since many solution channelways can be expected in the limestone. Other than the artesian water, local zones of saturation above the piezometric surface can be expected, and these zones would have to be eliminated by pumping or ditching if an area such as this were to be mined dry. AREA II Area II (fig. 12) includes a number of exposures located on the east and west side of the Chipola River just east of Marianna, south of the Florida Caverns State Park and north of the confluence of Spring Creek and the Chipola River. Here a number of topo- graphic lobes point inward and southward toward the Chipola River. These rounded hills expose the Marianna limestone with a minimum of overlying material at an elevation of 100 to 105 feet above sea level. The top of the Marianna is expected to be progressively lower southward since the dip of the formation is about 14 feet per mile toward the south. Generally, the Marianna limestone is overlain by the Suwannee limestone and or the Tampa sediments; but this overlying material may have been removed to varying thicknesses depending on the extent of the local erosion. LIMESTONE RESOURCES The Marianna limestone in the area is of reasonably high purity, being above 95 percent in calcium carbonate content (tables 5, 6). The overlying Suwannee limestone as exposed at Loc. JRL-3-2 shows an appreciable amount of magnesium carbonate and silicon dioxide. Noteworthy exposures of limestone in Area II from which samples were taken are Loc. JRL-3-1, Loc. JRL-3-2, Loc. JRL-10, Loc. JRL-11, and Loc. JRL-20 (fig. 12). The N/.NE'it sec. 2, T. 4 N., R. 10 W., is a noteworthy exposure where a hundred yards or so east of the graded road the face of an old quarry can be seen. West of the graded road (Loc. JRL-20) a northeast-southwest elongate hill exposes the top of the Marianna limestone at about the 103-foot level. This hill is probably overlain by a few feet of dolomitic Suwannee limestone. South of the northern boundary of sec. 2, where the graded road leaves the section, the Marianna and Suwannee limestone are exposed along the road at about 103 feet above sea level. In the SWl/.NW/1. and NWl/tSWl/t sec. 35, T. 5 N., R. 10 W., a north-south trending elongate rounded hill exposed the Marianna limestone below the 103 feet of elevation. Large quantities of rock can probably be produced from this site. As above, the Marianna is probably overlain by the Suwannee limestone. On the west side of the Chipola River, east, northeast and southeast of the city of Marianna, exposures occur on hills that are elongated perpen- dicularly to the river. Many of these exposures are in residential areas. Nevertheless, they are mentioned since they further index the top of the Marianna limestone at an elevation of about 103 feet, and may help find accessible mining locations. The piezometric surface would stand somewhat lower in Area II than Area I because of artesian discharge into the Chipola River. In all probability, this artesian water surface would stand at about 80 feet. Thus, in the vicinity of the hills as discussed, which are present along the Chipola River, there would be approximately 20 feet of Marianna limestone available for mining. Local zones of saturation would be at a minimum in this area since there is good surface drainage. Loc. JRL-19 (fig. 12), though outside of Area II is noteworthy, since it represents a good exposure of the Marianna limestone. This old "chimney block" quarry, located in the SW/I.NWl/1 sec. 30, T. 5 N., R. 9 W., lies about 2 miles northeast of Area II. The top of the Marianna limestone in the quarry stands at 103 feet and the floor of the quarry stands at 81 feet above sea level. The 50 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO bottom of the quarry is quite near the potential head of the artesian water, and the rock would have to be mined underwater if the quarry were deepened only a few more feet. The rock in this quarry exceeds 95 percent calcium carbonate with traces of magnesium carbonate, silica, iron and clay. The limestone occurs in many places of the immediate area at an elevation of about 103 feet. Local depressions on the surface away from the quarry indicate that the rock has deteriorated, thus the top of minable rock, away from the quarry, will occur at elevations lower than 103 feet. No estimate has been made as to the depth at which the underlying Crystal River formation will be encountered, but a projection of the contact of the various limestone and Crystal River formations from the bridge east of Marianna into sec. 30 would place the Crystal River limestone near the surface in this area. Locally the overburden is red, clayey sand which will vary in thickness from 1 to 10 feet. AREA III Area III (fig. 13) includes a number of exposures which for the most part are located along the Bump Nose Road. Area III trends generally in a north-northwesterly direction from the eastern part of sec. 32, T. 5 N., R. 10 W., on the northern boundary of the city of Marianna to the SEI/4 sec. 7, T. 5 N., R. 10 W. The area under consideration lies just west of the Chipola River and the northern portion ends in the flood-plain swamp. Many exposures of limestone, the locations where limestone occurs at a shallow depth beneath the ground, are present in Area III. The locations described are the more obvious exposures of rock along the roads. The rock is exposed in roadside ditches, in small "chimney stone" quarries, in fields, and one cave is present just to the west of the road in the northern part of the area. The limestone exposures as noted on figure 13 are Loc. JRL-6, Loc. JRL-7, Loc. JRL-8 and Loc. JRL-9 (tables 5, 6). Additional exposures may be seen from Loc. JRL-7 northward to the roadside cave mentioned above, located in the NWI/SE1/4SE/4 sec. 7, T. 5 N., R. 10 W. The four formations exposed in this area are the Crystal River formation, Marianna limestone, Suwanne limestone and the sediments of the Tampa stage. Limestone of the Crystal River and Marianna formations analyze the highest purity and total the Si ,. . .. EA *4-;" ... r', Y-: 'J ,1^ ^-. , .i :" - ^ ," , I .' .. E .10 . : - .. .- ,. : Kf N 4RL l A .-_.._ -.. . .-.. ..... I- . . $ ., . tt -i 29 .. . R EA, A'.1. _- .- V_.,, so po ti Ae I an V ackson ounty(Seefigur3-f quadranle in 'ex ,~1" i ." ".- ,.-I quadirangle index.) 52 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO greatest tonnage. Both formations exceed 95 percent calcium car- bonate content. The Suwannee limestone contains as high as 34 percent magnesium carbonate but is limited in tonnage. The Tampa sediments consist of clays and calcareous dolomitic clays. Rock of reasonably high purity and high tonnage can be seen on the north side of a hill at Loc. JRL-8. On the flank of the hill there is exposed in a road ditch, limestone which would represent 40 vertical feet of Crystal River and Marianna limestone. The calcium carbonate content at this section will exceed 97 percent. Moore (1955, p. 42) placed the Crystal River-Marianna contact at 93 feet at his Loc. J-77 at the bottom of the hill. Lying above, at. about 127 feet is the Suwannee-Marianna contact and overlying this contact the thin, calcareous dolomitic shaley material comprising the Suwannee (Byram?) does not exceed 4 feet in thickness. About 0.7 miles north-northwestward from Loc. JRL-8 the Marianna-Suwannee limestones are exposed on the south flank of an east-west trending hill at Loc. JRL-9. The contact between the two formations lies at 145 feet, with an unknown thickness of Marianna present and at least 13 feet of calcareous dolomitic Suwannee (Byram?) shal being exposed. East and west of this exposure and generally below the 145-foot Marianna-Suwannee contact, rather high tonnages of high purity limestone should be found. Quarries should penetrate the very pure limestone of the Crystal River formation at some point above 93 feet elevation. The amount of overburden to be stripped could be controlled by careful prospecting in this area. The maximum thickness of the overlying calcareous dolomitic shale is unknown, but the thickness of this capping material is 13 feet at this location and would probably reach its maximum thickness in the subsurface 0.8 mile northwestward from Loc. JRL-9 at the junction of Bump Nose Road and St. Johns School Road (fig. 13). At this road crossing the calcareous dolomitic shale is overlain by more recent sands and clays of the Tampa formation (Tampa stage) as stated by Moore (1955, pl. I). The piezometric surface in the southern portion of Area III should not be over 90 feet above sea level. Thus, about 40 or 50 feet of Marianna and limestone of the Crystal River formation are available in this part of the area for dry mining. At Loc. JRL-7, which lies 0.9 mile northwest of Loc. JRL-9, is an intermittent section down the flank of a north-south trending topographic ridge which continues to the northeastern corner of LIMESTONE RESOURCES sec. 19, T. 5 N., R. 10 W. The Marianna-Crystal River contact should occur at this corner but it is obscured by overlying detrital material. The Marianna-Suwannee limestone is exposed at an elevation of 159 feet, southward from the previously mentioned corner. The calcareous dolomitic Suwannee shale (Byram?) lying above the Marianna limestone is exposed up the slope of the hill to an elevation of 167 feet. At Loc. JRL-6, which lies a short distance southwest of Loc. JRL-7, the Suwannee (Byram?) is exposed on the surface at an elevation of 163 feet. Overlying this calcareous dolomitic shale is a thin veneer of clays and sands of the Tampa formation and younger sediments. As in the southern part of Area III, the amount of overburden to be handled above the Marianna limestone, could be minimized by mining below the Suwannee-Marianna contact contour (159 feet) and around the hill, choosing a location with a minimum of overlying younger sediments. The piezometric surface in this northern part of Area III is probably no higher than 90 feet above sea level. Thus, near Loc. JRL-7, there should be about 69 feet of Marianna limestone avail- able for dry mining above the potential head of the artesian water. Other than artesian water, local zones of saturation and runoff would have to be accounted for. Northward toward the boundary of Area III in the NEI/iNEI/E sec. 18 and in the SEI/VSEI/i sec. 7, both of which are in T. 5 N., R. 10 W., two exposures of Crystal River limestone occur (fig. 13). Each is located on a slight topographic rise. In each instance, the exposure is about 100 feet above sea level. The upper foot or so of the exposure has undergone recrystallization and is indurated to well indurated. Occasional stringers and small pods of indurated to well indurated limestone occur below the indurated surface and pass into the softer rock beneath. Probably the piezometric surface here also stands at 90 feet, thus leaving approximately 10 feet of limestone available for dry mining. Continued mining to a greater depth could be carried out by floating dredges or draglines. The largest percentage of indurated rock in Area III probably lies in this vicinity. AREA IV Area IV (fig. 13) is composed of a number of limestone exposures along State Highway 73, just northwest of Marianna. Area IV lies between Marianna and the intersection of State 54 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO Highway 73 with U. S. Highway 231. The area extends from the NW1/ sec. 31, T. 5 N., R. 10 W., to the SEI/i sec. 16, T. 5 N., R. 11 W., roughly 2 miles north of the Louisville and Nashville Railroad. Minable deposits of limestone extend far beyond the limits of Area IV and it is hoped that the area description will serve as a partial index to the immediately surrounding region. The exposures occur as road cuts, limestone sinks and quarries. The locations in Area IV are Loc. JRL-5 (the Marjax Company; owner, Mr. J. C. Corcoran), Loc. JRL-21-A and 21-B (the quarries of the currently inoperative Marianna Limestone Products Company; owner, Mr. Sam Smith), Loc. JRL-29 and Loc. JRL-4. The important limestone formations in Area IV are the Crystal River formation and the Marianna limestone. As a general rule, limestone of the Crystal River formation here exceeds 97.5 percent calcium carbonate and the Marianna limestone exceeds 94 percent calcium carbonate, each of which contains traces of magnesium carbonate, sand, iron and clay (tables 5, 6). The Crystal River formation-Marianna limestone contact is 120 feet at Loc. JRL-21-B (Moore, 1955, p. 41, reports this contact as 115 feet at his J-5). Southeastward 1.5 miles at Loc. JRL-29 (Moore's J-74) the same contact can be observed at 105 feet above sea level (fig. 13). The above contacts are in keeping with the dip of the Marianna which is about 13 feet per mile in this area. The elevation of Marianna limestone-Suwannee limestone (Byram?) contact in this area is not known exactly, but an eleva- tion on the top of the Marianna at Loc. JRL-21-B was 161 feet. This elevation must be quite close to this contact for this area since it is in keeping with the same contact at Loc. JRL-7 which is 2.5 miles eastward along strike. About 0.9 mile southwest of Loc. JRL-21-A and 21-B (Moore, 1955, p. 50) notes the elevation of the Marianna limestone-Suwannee limestone (Byram?) contact, at his J-173 and J-174, as 137 feet. It follows that in the southern part of Area IV this contact would be at a lower elevation since the Marianna limestone and the Suwannee limestone dip at the rate of 12 to 15 feet per mile toward the south. Local irregularities along the formational contact will nevertheless give a varying contact elevation. Exposures of the Suwannee limestone along State High- way 73, south of Loc. JRL-5, at Moore's Loc. J-3 (SWI/t sec. 30, T. 5 N., R. 10 W.) occur at 143 feet. The contact between the Marianna and the Suwannee would be between 137 feet and 140 feet, if the regional dip is applied to known elevations in the vicinity. LIMESTONE RESOURCES At Loc. JRL-4 (SWI/.NWI/1 sec. 22, T. 5 N., R. 11 W.) an elevation on top of the Marianna limestone is 135 feet. A short distance northeastward near the foot of the hill, Tanner Springs emerges from the Crystal River limestone. This spring marks the northern terminus of a northeast-southwest trending hill. The piezometric surface stands at about 90 feet in this area, thus 45 feet of Marianna limestone and limestone of the Crystal River formation are available above the potential head of the artesian water. The Crystal River-Marianna contact should be at an elevation of about 120 feet at this site. Overburden in the vicinity of the exposure varies from 1 to 8 feet. The 90-foot piezometric contour parallels the general trend of Area IV; therefore, there should be a maximum of 71 feet of lime- stone of the Crystal River and Marianna available at Loc. JRL-21-A and 21-B, 45 feet of the same limestone available at Loc. JRL-29 and 46 feet of the same available at Loc. JRL-5, before the potential head of artesian water would force dry mining operations into wet mining practices. In each location above, the calcium carbonate percentage should increase after mining enters the limestone of the Crystal River formation. Other than artesian water, the only water to be encountered in mining would be that from locally saturated zones above the piezometric surface, and inflow into the area. These local zones of saturation above the piezometric surface would fluctuate with rainfall and season. AREA V Area V (fig. 14) is a north-south trending area extending from the SWI/, sec. 32, T. 5 N., R. 11 W., to the NWI/1. sec. 20, T. 5 N., R. 11 W. The exposures lie in discontinuous locations to the east and north of Cottondale. The exposures occur in sinks, road cuts and in the quarry of the West Florida Lime Company. The locations in Area V are Loc. JRL-1, Loc. JRL-16, Loc. JRL-17, Loc. JRL-23, and Loc. JRL-28 (tables 5, 6). The major limestone present in this area is the Marianna lime- stone, though limited exposures of Suwannee limestone (Byram?) and sediments of the Tampa stage are present. No definite formational contacts are noticeable on the surface but a few generalizations can be made. At Loc. JRL-28, the top of a calcareous magnesium shale is 146 feet in a road cut on U.S. Highway 90. At about 142 feet the exposure definitely increases 56 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO .O! Bo t ,o j " V -- \ Sond nd U.jv :,- y "o*. :_;/J ., ..- 2 . ...-. -. -. :. .... .- .-- / , 16 '" "- "" 'YA " Gnat s I A - yw,., t ; i , R SCALE 1 2400C =..- i- rl =.. :_ L'_- 1Z= : --= .. -.. ..... I Figure 14. West-central portion of Cottondale East quadrangle showing po- tential limestone producing Area V, Jackson County. (See figure 3 for quad- rangle index.) LIMESTONE RESOURCES in calcium carbonate and appears somewhat like the Marianna limestone. Moore (1955, pl. I) maps the Marianna-Suwannee- Tampa formational contacts in this area but, nevertheless, it is not clear whether the above location is the Marianna-Suwannee contact or the Marianna-Byram contact. Northward from this point toward the Louisville and Nashville Railroad, in the vicinity of Loc. JRL-23, exposures occur between the 140- and 150-foot contour. Here, since the lower portions of the exposures have been quarried for "chimney rock," the occurrence of the Marianna limestone is suggested. Northward, and a few feet south of the Louisville and Nashville Railroad tracks at Loc. JRL-17, a pinnacle of what appears to be Marianna limestone occurs at 149.3 feet (near a U.S. Geological Survey bench mark). Moore (1955, p. 50) reports an exposure of Marianna limestone in this area located in the southwest corner NWl/NW'/i sec. 32, T. 5 N., R. 11 W. (Moore's J-86) where the elevation of the top of the rock is 136 feet above sea level. Florida Geological Survey well W-1783 at the top of the hill north of Moore's locality encountered the Marianna limestone at essentially the same elevation as that of Moore. It is thus pointed out that the top of the Marianna lime- stone is higher in this area than hitherto reported. Northwest- ward 1,800 feet from Loc. JRL-17 in the northwest corner of NEIINEI/I sec. 31, T. 5 N., R. 11 W., at an elevation of 150 feet, is an exposure of the calcareous dolomitic shale facies of the Suwannee or what may be the Byram formation. At Loc. JRL-16, about 1 mile north of Cottondale, the Marianna limestone is being mined by the West Florida Lime Company. The natural top of the exposure is at 143 feet, and mining had pro- gressed to an elevation of 123 feet by October 1958. Lying above the upper surface, there is a 3-foot stratum of dark red clay. If this red clay material is in part an insoluble residue from the underlying Marianna limestone, it would point favorably toward a separate origin for the brown calcareous dolomitic shale which in other places (figs. 12, 13, 14) lies above the Marianna limestone, thus ruling out any concepts which would favor the brown shale as weathered Marianna. Northward in the NWlM/ sec. 20, T. 5 N., R. 11 W., a road cut at Loc. JRL-1 is thought to expose the Suwannee limestone (Moore, 1955, pl. I), though the lithology is quite similar to the Marianna limestone. The top of the exposed rock here is 161 feet. Better exposures of limestone can be observed across the highway at Loc. JRL-1-2, as well as southward along a graded county road. The piezometric surface at Loc. JRL-1 is about 90 feet. Thus 58 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO a maximum of 71 feet of Marianna and underlying Crystal River limestone is available for dry mining. The piezometric surface stands at about 85 feet at Loc. JRL-16 and about 80 feet in the vicinity of Loc. JRL-17, Loc. JRL-23 and Loc. JRL-28. Thus, there is available at Loc. JRL-16 about 58 feet and at the latter three locations a maximum of 69 feet of limestone lying above the potential head of artesian water. Other than artesian water, local zones of saturation, perched water and surficial inflow can be expected and dealt with by standard mining practices. AREA VI Area VI (fig. 15) is a small area of exposures located in the NI/,SEI/' sec. 32, T. 6 N., R. 11 W., in the N1/! sec. 32, T. 6 N., R. 11 W., in the SEIASWI/ sec. 29, T. 6 N., R. 11 W., and in the NWI/.SW sec. 33, T. 6 N., R. 11 W. The locations present in the area are Loc. JRL-18-1, Loc. JRL-18-2, Loc. JRL-25, Loc. JRL- 26-1, Loc. JRL-26-2, and Loc. JRL-27. The exposures are represented by three limestone quarries and a "chimney rock" quarry, none of which are presently being operated. Numerous exposures of limestone occur at the head of Waddells Mill Pond in the southeastern edge of the area. All of the limestone in the area is mapped by Moore (1955, pl. 1) as the Crystal River formation. The rock exceeds 97.6 percent calcium carbonate, and contains traces of magnesium carbonate, silica, iron and clay (tables 5, 6). With the exception of Loc. JRL-25, the remaining quarries have been mined to a depth of about 30 feet, none of which appear to have been mined to the elevation of the potential head of artesian water. The piezometric surface in the area stands at about 95 feet, however; the level of the water at the spring which forms Waddells Mill Pond is about 90 feet. This decrease in the piezometric surface elevation at the spring is due to the free movement of water seeking an easy outlet thus causing a local cone of depression around the spring. In the vicinity of Loc. JRL- 18-1 and 2, about 47 feet of Crystal River formation is available for mining. This elevation would limit mining to a point about 17 feet below the present lowest point in this quarry. Adjacent to Loc. JRL-25, Loc. JRL-26-1 and 2, and Loc JRL-27, there would be about 37 feet, 35 feet, and 32 feet, respectively, of limestone available for dry mining above the potential head of artesian water. In addition to the above, perched 4 SCALE 1:24000 1 MILE Figure 15. Southwestern portion of Sills quadrangle showing potential limestone pro- ducing Area VI, Jackson County. (See figure 3 for quadrangle index.) z 0 C) w tn -- 60 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO water and local zones of saturation may be encountered above the piezometric surface. AREA VII Area VI (fig. 16) is a small area south of Ocheesee Pond where limestone is exposed in a shallow road cut and also in a drainage ditch. The area is located in the SE/ sec. 18 and in the SWI sec. 17, T. 3 N., R. 7 W. Moore (1955, pl. I) maps the area as underlain by the Tampa formation (Tampa stage). Many exposures occur in this portion of Jackson County south of Sneads, SCALE 1:24000 S0 1MILE Figure 16. Southwestern portion of Sneads quadrangle showing potential limestone producing Area VII, Jackson County. (See figure 3 for quadrangle index.) LIMESTONE RESOURCES between Ocheesee Pond and the Apalachicola River. The area delimited as Area VII was set aside since the Tampa sediments as exposed here is unusual for its high percentages of silica, calcium carbonate and magnesium carbonate (table 6). At Loc. JRL-13, the silica exceeds 55 percent whereas the calcium and magnesium carbonate together only slightly exceed 40 percent of the total analysis (tables 5, 6). In addition, this sample has greater than 0.73 percent clay fraction. This clay percentage is the highest of any limestone sampled in the three-county area. The top of the Tampa sediments here stand at 122 feet and 0.7 mile east-northeast at Loc. JRL-12 the elevation of the top of the Tampa is 142 feet. At this locality the limestone contains just under 17 percent silica with over 81 percent calcium and magnesium carbonate. This sample contains over twice the magnesium carbonate content of Loc. JRL-13. It would be a hazardous guess to state that the Tampa at Loc. JRL-12 would become more siliceous and less dolomitic with depth, since vertical and horizontal variations can be expected. Only drilling could prove the character of the formation. The piezometric surface in the area should stand in excess of 70 feet; therefore, a maximum of 52 feet of limestone at Loc. JRL-13 and 72 feet at Loc. JRL-12 are available for mining before the potential head of artesian water would be encountered. Surficial runoff, local zones of saturation and perched water can be expected locally and dealt with by standard mining practices. Lying northeast of Area VII, south of Sneads and west of the Apalachicola River, are additional exposures. The elevation of these locations are known, but no analyses are available. All of the locations occur in the Chattahoochee formation of the Tampa stage. The top of the Chattahoochee at Loc. JRL-30 stands at 108 feet; at Loc. JRL-31, 100 feet; at Loc. JRL-32, 75 feet; and, at Loc. JRL-33, 110 feet (fig. 17). The following locations of Moore (1955, p. 64) fall within this general area: J-64, J-69, J-70, and J-71. The piezometric surface in this general area will probably stand at an elevation in excess of 70 feet above sea level. Thus a maximum of 40 feet of limestone is available above the piezometric surface. Loc. JRL-15 (fig. 18) is an additional location lying about 5.5 miles southwest of Area VII (Moore's 1955, pl. I, J-131). Here the sediments of the Tampa are exposed at an elevation of 133 feet in the NWI/tNEI/& sec. 32, T. 3 N., R. 8 W. The exposure contains over 51 percent calcium carbonate, over 38 percent magnesium carbonate, over 9.4 percent silica, and traces of iron and clay. For 62 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO the most part, the rock is located just above or in the stream bed and mining could best be undertaken along the flanks of and parallel to the stream in the narrow valley. Mining in this manner would probably limit the amount of overburden to be removed to less than 10 feet. The piezometric surface stands at a minimum of 70 feet above sea level in this area; thus, a maximum of 63 feet of the limestone I f I . Figure 17. East-central and southeast portion of Sneads quadrangle showing sample locations JRL-30, 31, 32, 33, Jackson County. (See figure 3 for quad- rangle index.) SCALE 1:24000 a0 r4 Ci) 0 z t!1 M Ci) 0, 0 c) Figure 18. North-central portion of Altha East quadrangle showing sample location JRL-15, Jackson County. (See figure 3 for quadrangle index.) MILE I 64 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO would be available before the potential head of artesian water would be encountered. The presence of a stream in this area along with local saturated zones would be the major contributors to water problems at this location. The establishment of the vertical as well as horizontal lithologic changes could only be determined by drilling since the exposure is confined to a stream course. Only a small portion of the rock is visible. Lying far to the southwest of Area VII and on the east bank of Chipola River, Loc. JRL-14 exposes a 4-foot exposure of the Suwannee limestone (as mapped by Moore, 1955, pl. I) at an elevation of 48.8 feet (fig. 19). This location is in the NEI/1SEI/. sec. 30, T. 3 N., R. 9 W., and is lithologically and chemically quite similar to the Tampa stage. The Suwannee limestone here contains /" 01 o RkCr~ k\ -' i . S...... Ro ,, A C, 1AL9 E 1 7s 20 Sink Cr.. SCALE 1:24000 1 4 0 14MII Figure 19. South-central portion of Oakdale quadrangle showing sample location JRL-14, Jackson County. (Sec figure 3 for quadrangle index.) LIMESTONE RESOURCES over 57 percent calcium carbonate, 35 percent magnesium car- bonate, 6 percent silica and traces of iron and clay. The formation will probably be encountered in the immediate area away from rock exposures at elevations slightly higher than the exposure elevation. The stratum top will generally follow the land contour but at a somewhat reduced rate of change. The clayey overburden along the Chipola River, where the rock is exposed is about 4 feet thick and locally may increase to about 10 to 15 feet in thickness. The piezometric surface probably stands rather close to the eleva- tion of the Chipola River; therefore, any mining operation would probably be a wet one. The above locations (Loc. JRL-14 and Loc. JRL-15), as well as the other locations located outside of Area VII (Loc. JRL-30-31- 32-33) are located on a northeast-southwest trend at the extremities of Area VII. Moore's (1955, pl. 1) locations J-129- 115-114-72-64-69-70-71 all fall into this northeast-southwest pat- tern of exposures which collectively could be termed a super area. This super area is not subdivided because of general lack of lithologic information. One location of note lying well to the northeast of Area VII but within what has been referred to as a super area, is Loc. JRL-32 (fig. 17). This site is in the SE/I.SWI/. sec. 12, T. 3 N., R. 7 W. Here the Chattahoochee formation is exposed at 75 feet above sea level. The exposure exceeds 10 feet in thickness and is located near the head of the water discharge canal at the steam power plant. This limestone occurs along the escarpment which marks the western edge of the flood plain of the Apalachicola River. Though not observed, exposures of limestone should occur along this escarpment both above and below the power plant, all of which are below the Jim Woodruff Dam. The rock is covered by a thin mantle of surficial sediment but the extent of this mantle could only be proven by further investigation and drilling. The surface of the limestone should generally follow the contour of the land rising to the westward toward Loc. JRL-33, where it is exposed at an elevation of 110 feet. This general location is very well situated geographically since it is adjacent to the Apalachicola River where barge transportation is available. In addition, the exposures are only 2.5 miles from both U.S. Highway 90 and the Louisville and Nashville Railroad (fig. 1). No analysis of Loc. JRL-32 is available but the properties of 66 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO this limestone would probably be somewhat similar to Loc. JRL-12 and 13. AREA VIII Area VIII (fig. 20) is a dry valley exposure and a sink about 3 miles southeast of Cottondale located in parts of the S1/ sec. 3 and 4, Wi/ sec. 10, E'i/ sec. 9, N'72 sec. 16, and S!, sec. 10, all of SCALE 1:24000 0 I MILE Figure 20. Southwest portion of Cottondale East quadrangle showing potential limestone producing Area VIII and sample location JRL-24, Jackson County. (See figure 3 for quadrangle index.) ;=-~=hPILI-E=9L-b_--- i-I~__~ _~3~-1 1____~-~_=51 __1 -- ~ -I~-~---- LIMESTONE RESOURCES which are in T. 4 N., R. 11 W. Locations in Area VIII are Loc. JRL-22 and Loc. JRL-24. The Marianna limestone is exposed along the edge of the valley and in places along the floor of the valley. Presently, the valley is dry and used for cattle grazing. Moore (1955, pl. I) shows the Marianna limestone as overlain in this area by the Suwannee (Byram?) limestone. The valley in the western part of Area VIII is reported by Mr. Leland Thomas of Cottondale (personal com- munication) to contain exposures such as that in the eastern valley. Mr. Thomas also reports the presence of limestone in the large sink located in the WI/._SEI/. sec. 10, T. 4 N., R. 11 W. The elevation of the Marianna limestone (Loc. JRL-22) on the eastern side of its easternmost valley in Area VIII and lying along the section line separating secs. 3 and 10, T. 4 N., R. 11 W., is 125 feet above sea level. The exposures can be traced intermittently north and south in the valley, rising and falling with local irregularities and the dip of the formation. The limestone exceeds 94 percent calcium carbonate along with minor percentages of silica, magnesium carbonate, iron, and clay (tables 5, 6). The piezometric surface in the area stands at about 75 feet. Since the elevation of the limestone at Loc. JRL-22 is 125 feet, a maximum of 50 feet of limestone could be mined before the potential head of artesian water would be reached. Area VIII is favorably located about 1 mile south of the Louisville and Nashville Railroad on U. S. Highway 90. Good drainage and easy access to the area further favors this area. By mining along the exposure, overburden removal could be kept at a minimum. Additionally, a calcareous, dolomitic shale over- burden may reveal a stratum of some economic importance. LOCALITY DESCRIPTION WASHINGTON COUNTY (See tables 1 and 2) Loc. WRL-1 (fig. 5), Falling Water Sink located on the land of the International Paper Company in the NW/I.NWi/i. sec. 27, T. 4 N., R. 13 W. (Wausau, U.S. Geological Survey topographic quadrangle), exposes 11.5 feet of light gray, indurated, massive, chalky, sandy, silty, argillaceous, fossiliferous limestone of the Chattahoochee formation, containing lenses and seams of blue-green clay. According to Vernon (1942, p. 60), this Tampa limestone is underlain by 72.3 feet of exposed Suwannee 68 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO limestone. At this locality only the Chattahoochee formation was sampled. The exposures in the immediate vicinity of Falling Water Sink were the only ones noted in the immediate vicinity of Falling Water hill, though the Chattahoochee formation should be expected to be exposed rather near the surface on the flanks of the hill at the 170-foot contour. In a few instances, this is true and a rather abrupt change in soil color and texture at the 170-foot contour indicates that the Tampa limestone is near the surface. An example of the above can be seen on a graded road near the center of sec. 21, T. 4 N., R. 13 W. Here the soils change from sands to red clays indi- cating the degraded nature of the underlying limestone. In the area of exposure of this formation, the adjacent overburden is excessive and difficulty may be experienced when trying to prove a deposit. Furthermore, the general area is rather picturesque with its dense foliage, 70-foot waterfall and numerous caves. Residents in the Chipley area are utilizing this spot as a park for recreation and picknicking, and efforts are currently being made to dedicate this area as a State park. Loc. WRL-3 (fig. 4), a road cut on Falling Water Road, 2.5 miles due south of Chipley, in the NI2-SE/. sec. 16, T. 4 N., R. 13 W. (Waursau, U.S. Geological Survey topographic quadrangle) exposes a 29-foot stratigraphic section along the road. The exposure is a well indurated to indurated, dense to chalky, fine, equigrained, massive, coquinoid limestone. The dense portion of the limestone occurs in irregular masses and stringers on the surface, and in the subsurface. Vernon (1942, p. 64) referred this exposure to the Suwannee limestone. Loc. WRL-4 (fig. 4), a sink located on the land of Mr. John Dunn in the NE/'SWI/t sec. 16, T. 4 N., R. 13 W. (Wauisau, U.S. Geological Survey topographic quadrangle), exposes a vertical 14-foot face of light cream, indurated to poorly indurated, chalky to dense, coquinoid Suwannee limestone. The sample is a spot sample. See Loc. WRL-4-B. Loc. WRL-4-B (fig. 4) is the same as the above location, but more representative of the exposure, since it is a channel sample. Loc. WRL-4-C (fig. 4) is the same as Loc. WRL-4 except it is a spot sample. The two types of sampling were used as a check against sampling techniques and to determine gradual changes in rock composition. LIMESTONE RESOURCES Loc. WRL-5-1 (fig. 5), a road cut located 0.10 mile north of the southwest corner, SW/,tSWJ1i. sec. 36, T. 4 N., R. 14 W., (Wausau, U.S. Geological Survey topographic quadrangle), exposes a light cream, indurated to poorly indurated, dense to chalky, coquinoid Suwannee limestone. The dense, well indur- ated portion of the rock occurs as seams a few inches to a few feet wide, or as a surficial secondary limestone. The more indurated portions of the exposure would be suitable for aggregate. Loc. WRL-5-2 (fig. 5) is the same location as Loc. WRL.5-1, but 50 yards north on the same side of the road. The lithology is about the same as Loc. WRL-5-1 and it represents a spot sample about 10 feet lower in the section as exposed along the road. This exposure was identified by Vernon (1942, pl. 2) as the Suwannee limestone. The dense or well indurated zones in this exposure and in Loc. WRL-5-1 represent only a small percentage of the total rock. Loc. WRL-6 (fig. 5) is a portion of a composite sink and roadside exposure located in the SW1/NE'~i sec. 36, T. 4 N., R. 14 W. (Wausan, U.S. Geological Survey topographic quadrangle). The limestone as exposed on the sink face varies from a tan to light gray, indurated to poorly indurated, dense to chalky, massive coquinoid Suwannee limestone. The lithologies in this area vary quite rapidly from a dense recrystallized rock to a chalk, each containing only a few visible fossils. Commonly, quite fossiliferous beds will be found adjacent to both of the above lithologies. Beds of chalk may pass vertically as well as horizontally into a much less chalky and more coquinoid to coquina faces. In some instances, there has been a moderate amount of recrystallization and slight silicification. The recrystallized limestone generally is present on the horizontal surface of the exposure where it may attain a thickness of 2 feet. These recrystallized portions also occur as stringers passing vertically or obliquely downward from the surface to variable depths. The silicified zones are sometimes found on the uppermost level of the exposed rock and in some instances occur on the exposed vertical faces. Generally, the face of the exposure is weathered to a depth of 2 inches. Sample WRL-6 was collected from the bottom of the section and the analysis represents the near chalky phase of the limestone. The sample was not in place since it represented a rejected sawed block. It was collected and analyzed chemically to determine the 69 70 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO composition of that particular lithology. The exposed face of rock which lies at the south end of the sink is 29.1 feet in thickness. The rock is covered for the overlying 27.0 feet but is exposed in the unpaved roadbed at the very top of the section. The total thickness of the section of the exposed and covered limestone is 56.1 feet. The exposure is mapped by Vernon (1942, pl. 2) as the Suwannee limestone. Loc. WRL-6-B (fig. 5) is the same location as Loc. WRL-6, but represents the more fossiliferous zone within the sink. The rock is a tan to cream, brownish red speckled, indurated, mas- sive, fossiliferous limestone. The exposure is mapped by Vernon (1942, pl. 2) as the Suwannee limestone. Loc. WRL-6-C (fig. 5) is the same location as Loc. WRL-6 and Loc. WRL-6-B but it represents the chalky phase of the exposure. Here it is a light gray to tan, indurated to poorly indurated, equigrained massive chalk. This portion of the exposure has been sawed for chimney rock. The exposure is mapped by Vernon (1942, pl. 2) as the Suwannee limestone. Loc. WRL-7 (fig. 5), a road cut located in the southeast corner of NEI/iNEI/. sec. 32, T. 4 N., R. 13 W. (Wausau, U.S. Geological Survey topographic quadrangle), exposes a light gray to light cream, slightly argillaceous, arenaceous, chalky, indurated to poorly indurated fossiliferous limestone. Light blue-green seams and pockets occur occasionally. The exposure has the lithologic characteristics of the Chattahoochee formation. The exposure must be quite close to the Chattahoochee-Suwannee contact, since the contact on Falling Water hill (Loc. WRL-1) and at this locality (Loc. WRL-7) lie at approximately 160 feet. This exposure is mapped by Vernon (1942, pi. 2) as the Suwannee limestone. Loc. WRL-7-2 (fig. 5), a sink located in the NWI/INW/t sec. 33, T. 4 N., R. 13 W., about 0.2 mile northeast of Loc. WRL-7 (Wausau, U. S. Geological Survey topographic quadrangle) exposes a 10.5-foot vertical section of tan to cream, poorly indurated to indurated, dense to chalky, coquinoid Suwannee limestone. Loc. WRL-7-3 (fig. 5), a well developed sink in the NI/NEII/ sec. 32, T. 4 N., R. 13 W. (Wausau, U. S. Geological Survey topo- graphic quadrangle) on the property of Mr. C. C. Coleman, exposes a 34.6-foot section of light cream to light gray, poorly LIMESTONE RESOURCES indurated to indurated, chalky to dense, massive, coquinoid Suwannee limestone. A small stream flows southeast into the sink, where it disappears in a cavern at the base of the sink face. Loc. WRL-7-4 (fig. 5), a sink on the Finch farm in the Si/.NENI/.NWi/I sec. 33, T. 4 N., R. 13 W. (Wausau, U. S. Geological Survey topographic quadrangle), exposes a 21-foot section of light cream to light gray, poorly indurated to indurated, chalky to dense, massive, coquinoid Suwannee lime- stone. It is of interest to note that in 1922 Mr. Finch cut the blocks for his chimney from this sink. The point from which the blocks were cut lies about 20 feet below the presently over- grown bottom of the sink. Thus, in the past 36 years the sink has been filling by sheet wash from the surrounding cultivated fields at the rate of over one-half foot a year. It is of further interest to note that when Vernon (1942, p. 63) visited the sink in 1940-41 the exposure was 25 feet in thickness, whereas in 1958 the sink exposure was 21 feet in thickness. It appears that most of the filling occurred prior to 1940 at which time cultivation was probably at a maximum. Loc. WRL-8 (fig. 4), a sink behind Limestone Cemetery at the flower nursery of Mr. Dickinson, in the S/.NEI/& sec. 7, T. 4 N., R. 13 W. (Chipley, U.S. Geological Survey topographic quadrangle), exposed about 1 foot of limestone in 1955 at a low stand of the ground water. The top of the limestone at that time was about 57 feet above sea level (personal communication with Mr. Dickinson). By projecting the work of Vernon (1942, p. 37), it appears that the rock is the Crystal River formation. Because of the high stand of the water no sample was available at the time of the visit in May 1958. Loc. WRL-9 (fig. 4) lies 0.2 mile south of the intersection of an unpaved road with a paved road. The unpaved road is a north- south road splitting secs. 15 and 15, T. 4 N., R. 13 W. The exposure lies about 0.1 mile south of the northeast corner NEI./SE'1A sec. 15, T. 4 N., R. 13 W. (Wausau, U. S. Geological Survey quadrangle). The limestone exposed is a light cream, well indurated to poorly indurated, dense to chalky, massive, coquinoid Suwannee limestone. As in most exposures of the Suwannee limestone, the dense limestone portion occurs as pods and stringers, or as a surficial mantle. It usually constitutes a minor percentage of the total rock. The sample analysis was 72 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO made on the dense or more crystalline portion of the exposure. This location is flanked by Loc. WRL-10, Loc. WRL-11, and Loc. WRL-11-2. Loc. WRL-10 (fig. 4), a road cut in the NI/NWI/.SWi/ sec. 14, T. 4 N., R. 13 W. (Wausau, U. S. Geological Survey topographic quadrangle) exposes a short grade or slope section of about 3 feet vertical resolution. The limestone as exposed here is a light cream, indurated to well indurated, finely crystalline to dense, moldic, massive, fossiliferous Suwannee limestone. This sample locality is not representative of the rock as exposed in the general area but represents that portion of the limestone in the area which is the most indurated. Loc. WRL-11-B-1 (fig. 4), a sink in the EI/2NWI/iSWI! sec. 14, T. 4 N., R. 13 W., immediately south of Loc. WRL-10 (Wausau, U. S. Geological Survey topographic quadrangle), exposes a 30-foot section of Suwannee limestone. No aperture or cavern is visible in the sink for surface water discharge, but slumps commonly occur in the sink bottom after surface runoff has discharged through the sink. This sample is a 13.9-foot channel sample beneath Loc. WRL-11 and extends from the bottom of the sink at an elevation of 110 feet to an elevation of 123.9 feet. The Suwannee limestone as exposed at this elevation is a light cream to light gray, indurated to well indurated, fine grained, chalky, massive, fossiliferous limestone. The following two locations, Loc. WRL-11 and Loc. WRL-11-B-2 complete the channel sample for this locality. Loc. WRL-11 (fig. 4) is the same locality as Loc. WRL-11-B-1 and is a short channel sample from 123.1 feet to 125.1 feet, and a continuation of the Loc. WRL-11-B-1 channel sample. The Suwannee limestone as exposed here is a light gray to white, indurated to poorly indurated, slightly fossiliferous, massive chalk. Loc. WRL-11-B-2 (fig. 4) is the same location as Loc. WRL-11-B-1, and is a continuation of the underlying channel sample of Loc. WRL-11. The sample continues from an elevation of 126.9 feet to the top of the channel sample at 133.9 feet. At this location, the Suwannee limestone is a light cream to light gray, indurated, fine grained to chalky, massive, and is generally more fossiliferous than that portion of the section lying beneath. The upper 7 feet of the 30-foot exposure was not sampled LIMESTONE RESOURCES since it is badly weathered and would give erroneous results. These upper few feet are similar to the material directly beneath, but are more fossiliferous and better indurated. Loc. WRL-11-2-1 (fig. 4), a sink in the NEI/I.SE/I. sec. 15, T. 4 N., R. 13 W., 0.1 mile west-southwest of Loc. WRL-9 (Wausau, U. S. Geological Survey topographic quadrangle), exposes 28 feet of light cream to light gray, poorly indurated to indurated, chalky to coquinoid limestone containing occasional stringers, lenses and surficial secondary expression of well indurated, dense to finely crystalline, massive limestone. The latter lithology is but a small percentage of the total exposure. This sample, Loc. WRL-11-2-1, is the lower 9 feet of the 28-foot exposure. The entire 28 feet were channel sampled. Vernon (1942, p. 64) mapped this area as Suwannee limestone. Loc. WRL-11-2-2 (fig. 4) is the same as above, with the exception that the sample is taken from the overlying 11 feet above Loc. WRL-11-2-1. Loc. WRL-11-2-3 (fig. 4) is the same as sample Loc. WRL-11-2-1 with the exception that the sample is the uppermost 8 feet of the 28-foot exposure. Loc. WRL-12 (fig. 5), a sink with an 8.5-foot face on the northeast wall in the northeast corner NWI/.SW'/. sec. 36, T. 4 N., R. 14 W. (Wausau, U. S. Geological Survey topographic quadrangle), exposes a light cream to reddish cream, poorly indurated to indurated, chalky, slightly fossiliferous, massive limestone. Vernon, in a test pit (1942, p. 61) described bed 2 of this locality, W-27, as Suwannee limestone. Vernon's bed 2 is the same elevation as Loc. WRL-12. Loc. WRL-12 is 0.1 mile west of Vernon's W-27. Loc. WRL-13-1 (fig. 5), a sink with a 30-foot face of limestone located northeast of Piney Grove church (Duncan Church) in the N,/SE/.t sec. 36, T. 4 N., R. 14 W. (Wausau, U. S. Geological Survey topographic quadrangle), exposes a light cream to pinkish cream, indurated to poorly indurated, locally finely crystalline to dense, chalky to coquinoid, massive Suwannee limestone. Sample WRL-13-1 represents the lower 2 feet of the face of rock. The lithologies vary laterally and vertically. Loc. WRL-13-2 (fig. 5) is the same as Loc. WRL-13-1, except it is higher on the exposure, being at an elevation of 83.5 to 85.2 feet. 74 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO Loc. WRL-13-3 (fig. 5) is the same as Loc. WRL-13-1, except it is higher on the exposure at an elevation of 87.5 to 92.7 feet. Loc. WRL-13-4 (fig. 5) is the same as Loc. WRL-13-1, except it is higher on the exposure at an elevation of 98.3 to 104.3 feet. Loc. WRL-I1 (fig. 5), at a sink on the farm of Mr. L. W. Loyed, there is, on the north side of the westernmost sink, a pair of coalesced sinks, in the SW'NWi sec. 1 (along section line separating sec. 1 and se. 2), T. 3 N., R. 14 W. (Wausao, U. S. Geological Survey topographic quadrangle) exposes a 16-foot slumped section where 3 feet of limestone is visible. The rock. as exposed, is cream to reddish cream, poorly indurated to indurated, locally finely crystalline to dense, chalky, massive, fossiliferous Suwannee limestone. Loc. WRL-15-1 (fig 4), on the north side of the eastern sink of a double sink, in the SWI/SW10W see. 15, T. 4 N., R. 13 W. (Wasaun, U. S Geological Survey topographic quadrangle) there is exposed on the Sasser farm a nearly vertical exposure of light cream, dense to finely crystalline, sharp fossiliferous rock with poorly indurated, slightly chalky zones. Vernon (1942, p. 62) maps the area as Suwannee limestone. Sample Loc. WRL.15-1 represents a 2-foot sample from 146 to 148 feet. Lic. WRL-15-2 (fig. 4) is the same as Loc. WRL-15-1 except it represents a 1-foot sample at an elevation of 148 to 149 feet. Loc. WRL.16-I (fig. 4) on the north side of the western sink of the double sink as mentioned in Loc. WRL-15-1 on the Sasser farm there is exposed about the same lithology of the Suwannee limestone as in Loc. WRL-15-1. Sample WRL-16-1 represents a 4-foot sample, from 143 to 147 feet. Loc. WRL-1-2 (fig. 4), is the same location as Loc. WRL-16-1 except it represents a 3-foot sample from 147 to 150 feet. Bare rock is exposed on the surface for about 100 yards to the north and to the east of Loc. WRL-15-1, Loc. WRL-15-2, Loc. WRL-16- 1, and Loe WRL-16-2. Where exposed on the surface the rock is quite well indurated and represents a recrystallized or "casehardened" surface. The thickness of the indurated zones is unknown. Loc. WRL-17-1 (fig. 4), a sink about 270 yards north of Loc. WRL-15-1, located in the SEirNEi/SEI/ see. 16, T. 4 N, R. 13 W. (Waosau, U S. Geological Survey topographic LIMESTONE RESOURCES quadrangle), exposes 32 feet of light cream, poorly indurated to indurated, chalky to coquinoid and occasionally dense, fossiliferous Suwannee limestone. The dense zones are generally surficial recrystallized limestone, but may occur as lenses or vertical bodies of small extent. The sample collected was a 2- foot channel sample from an elevation of 100 to 102 feet. It was collected from the chalky zone. Loc. WRL-17-2 (fig. 4) is the same sink as Loc. WRL-17-1, except that the sample was collected at an elevation of 110 feet and from the dense or finely crystalline upper zone of the exposure. Loc. WRL-18 (fig. 5), a sink in the SEI/SEI/ESEI/. sec. 35, T. 4 N., R. 15 W. (Wausau, U. S. Geological Survey topographic quadrangle), exposes a 2-foot ledge of rock above the small entrance to a dry sink. The rock is a light tan to light cream, poorly indurated to indurated, chalky to coquinoid and occasionally dense, Suwannee limestone. Loc. WRL-19 (fig. 5), on the edge of a sink in the northwest corner of the SEI/SEI/1 sec. 35, T. 4 N., R. 14 W. (Wausau, U. S. Geological Survey topographic quadrangle), exposes a light cream, poorly indurated to well indurated, chalky to dense, Suwannee limestone. The sample was collected from the chalky zone. The recrystallized or dense zone is of surficial character and overlies the chalky zone. Loc. WRL-20 (fig. 6), along the Choctawhatchee River, 700 feet north from the end of a deadend graded road which terminates in the center of sec. 17, there is located in the northwest corner of the SWI1NEI1/ sec. 17, T. 3 N., R. 16 W. (Hinson Cross Roads, U. S. Geological Survey topographic quadrangle), 2 to 4 feet of light gray to light cream, indurated, equigranular, slightly chalky limestone which was mapped by Vernon (1942, pl. 2) as the Tampa formation (Tampa stage). Loc. WRL-21 (fig. 7), along the Choctawhatchee River at Spears Fish Camp, in the NEI/.SEI/. sec. 31, T. 2 N., R. 16 W. (Red- bay, U. S. Geological Survey topographic quadrangle), exposes 1 foot of medium reddish brown, well indurated, sandy macrofossiliferous limestone, which was mapped by Vernon (1942) as belonging to the Alum Bluff group (Alum Bluff stage). Loc. WRL-22 (fig. 8), along the east side of the Econfina Creek at the Boy Scout Camp in or near sec. 4, T. 1 S.. R. 13 W. 76 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO (Bennett, U. S. Geological Survey topographic quadrangle), exposes 3 feet of medium tan, poorly indurated to indurated, equigranular, slightly fossiliferous limestone near the water's edge, overlain by 10 feet of sandy shell marl, all of which was mapped by Vernon (1942) as the Choctawhatchee formation. The underlying stratum, which is that portion which was sampled, passes beneath the water level in the creek and is therefore of unknown thickness. HOLMES COUNTY (See tables 3 and 4) Loc. HRL-1 (fig. 10), a road cut in the SW/tNEI/ sec. 1, T. 5 N., R. 15 W., exposes about 1 foot of limestone in a small spring alongside an unpaved county road about 50 feet southeast of a bridge which crosses Wrights Creek (Bonifay, U. S. Geological Survey topographic quadrangle). The rock as exposed is a medium red-brown, poorly indurated, chalky, equi- grained, macro and microfossiliferous, coquinoid Crystal River limestone (Ocala) (Vernon, 1942, p. 45). Exposures in this area are limited and most likely will be seen under water and perhaps along the banks of Wrights Creek at low water. Loc. HRL-2 (fig. 9), a sink in the SW/tNEI/r sec. 3, T. 5 N., R. 17 W., (Prosperity, U. S. Geological Survey topographic quadrangle) exposes 4 feet of tan to medium reddish cream, well indurated to locally poorly indurated, dense to chalky, massive, fossiliferous Marianna limestone (Vernon, 1942, p. 55). The exposure is in the bottom of a small sink and since the exposure is quite limited, the above lithologic description could not be expected to persist for that unexposed portion. Portions of the limestone in this area may be usable as aggregate; however, a drilling program would be necessary to prove the extent of the indurated zone. Loc. HRL-3-1 (fig. 9), a sink in the center of the SEn/t sec. 3, T. 5 N., R. 17 W. (Prosperity, U. S. Geological Survey topographic quadrangle), exposes 28 feet of light cream indurated to poorly indurated, chalky to locally dense, massive, fossiliferous Marianna limestone (Vernon, 1942, p. 54, locality H-10). This sink lies roughly 1,400 feet south-southeast of Loc. HRL-2, and is located on the land of Mr. J. C. Melson. This location represents the lower 5.7 feet of what is probably the best LIMESTONE RESOURCES limestone exposure in Holmes County. The channel sample ex- tends from 120 to 125.7 feet. Loc. HRL-3-2 (fig. 9) represents the channel sample directly above Loc. HRL-3-1. It is roughly the central 9 feet of the upper 22 feet of the exposure. There is very little lithologic difference between Loc. HRL-3-1 and Loc. HRL-3-2, though there is a slight color and composition difference. Loc. HRL-3-2 is very light gray and Loc. HRL-3-1 is light cream in color. Chemically, Loc. HRL-3-2 contains only a trace of MgCo: whereas Loc. HRL-3-1 contains 1.26 percent MgCo:.. Normally, the MgCo:, content is more prevalent in the upper zone of an exposure; however, in this instance the reverse is noted. This slight difference in rock color and chemical composition sup- plements Vernon's (1942, p. 55) observation that the upper beds of this exposure resemble the Byram formation of Alabama. Since these upper beds cannot be differentiated into satisfactory subdivisions, Vernon (1942, p. 54) included the entire exposure in the Marianna limestone. Loc. HRL-4 (fig. 10), Ponce de Leon Springs, though developed, is currently not open. It is located east of the town of Ponce de Leon in the SEI/MSWI/. sec. 27, T. 4 N., R. 17 W. (Ponce de Leon, U. S. Geological Survey topographic quadrangle). No sample was collected, but the elevation of the limestone of the Tampa stage is 38 feet above sea level. Loc. HRL-5 (fig. 11) is Morrison Springs which is located roughly 5 miles southeast of the town of Ponce de Leon in Walton County, in the NEI1.NE/1I sec. 23, T. 3 N., R. 17 W. (Ponce de Leon, U. S. Geological Survey topographic quadrangle). Limestone of the Tampa stage is exposed beneath the water level of the spring, at an elevation of 9 feet above sea level. The water elevation at the spring is 30 feet above mean sea level. Loc. HRL-6 (fig. 11) is Blue Spring in the NWIA. sec. 9, T. 4 N., R. 17 W. (Prosperity, U. S. Geological Survey topographic quadrangle), 3.5 miles north-northwest of the town of Ponce de Leon in Holmes County. The elevation of the water at Blue Spring is 74 feet. The elevation of the top of the Tampa stage occurring in the spring is unknown. Loc. HRL-7 (fig. 9), a double sink on the Hudson farm in the SWI/.NWI/1 sec. 15, T. 5 N., R. 17 W. (Prosperity, U. S. Geological Survey topographic quadrangle), exposes a few small 78 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO boulders in its bottom. Since analysis of a few surface boulders would not give favorable results, no samples were collected. However, when Vernon (1942, p. 65) visited this locality, 8 feet of cream to light gray, sandy, argillaceous limestone was exposed, containing harder, white, crystalline, very fossiliferous, sandy limestone layers. He assigned the exposure to the Suwannee limestone. Since Vernon's visit in 1942, the sink has been partially filled by sheet wash from the surrounding fields. JACKSON COUNTY (See tables 5 and 6) Loc. JRL-1 (fig. 14), a road cut on the northwest side of U. S. Highway 231, located on the east side of the NWII.NW'/. sec. 20, T. 5 N., R. 11 W. (Cottondale East, U. S. Geological Survey topographic quadrangle), exposes 2.5 feet of light cream, poorly indurated, chalky, equigrained, microfossiliferous limestone. The geologic map of Jackson County, (Moore 1955, pl. I) places this exposure in the Suwannee limestone. The Marianna limestone underlies this deposit but, here, both the Suwannee and the Marianna limestones are quite similar lithologically and have essentially the same chemical composition (table 6). Loc. JRL-1-2 (fig. 14) is southeast and across U. S. Highway 231 from Loc. JRL-1. Here a combination sink and borrow pit 5.7 feet are exposed which represents that portion of the stratum directly beneath Loc. JRL-1. Loc. JRL-1 is mapped as Suwannee (Moore, pl. I) but lithologically and chemically it is quite similar to the Marianna limestone which is the next underlying formation. Loc. JRL-2 (fig. 12), on the south side of State Highway 164, 0.80 mile west of Blue Spring Road, in the center of the SWI/NEIA sec. 32, T. 5 N., R. 9 W., (Marianna, U. S. Geological Survey topographic quadrangle), exposes 3 feet of light cream, poorly indurated, chalky, equigrained, microfossiliferous Marianna limestone. Numerous exposures occur eastward in the area for roughly 1 mile and elevations on the top of the Marianna lime- stone vary from 109 feet to 118 feet along the road. Westward about 1,400 feet from Loc. JRL-2, Moore (1955, p. 47) placed the Marianna limestone-Suwannee limestone contact at 127 feet. The above exposures are a good example of the highly irregular solution surface which can be expected in Jackson County. Because of the soft nature of this Marianna limestone LIMESTONE RESOURCES the State Road Department maintenance crews are able to tilt their grader blades and cut the limestone to the slope of the road cut banks. South of Loc. JRL-2, the northern bluffs along Merritts Mill Pond expose Marianna limestone near their base. Here the various elevations on top of this limestone vary from 98 to 102 feet. The base of the exposed limestone is generally 80 feet above mean sea level. At the first bluff, one-half mile downstream from Blue Spring, it is interesting to note that 1 foot thick, flat lying, well indurated, dense layer of limestone is persistent within the Marianna limestone, at an elevation of 93 feet, for a distance of 400 feet. Loc. JRL-3-1 (fig. 12) is a roadside exposure just east of the Chipola River on U. S. Highway 90, adjacent to Marianna, Florida. This exposure is located in the Sl/.SWI/. sec. 2, T. 4 N., R. 10 W. (Marianna, U. S. Geological Survey topographic quadrangle). Here is exposed 15 feet of Marianna limestone. Overlying this location is 3 feet of indurated dolomitic limestone (Loc. JRL-3-2). The Marianna limestone is a light cream, poorly indurated, massive, chalky, equigrained, microfossiliferous limestone containing a very few localized stringers and nodules of in- durated limestone. This location is currently developed as a business site and samples were collected only as a lithologic check for control. Loc. JRL-3-2 (fig. 12) is just east of the Chipola River on U. S. Highway 90 adjacent to Marianna, Florida. This exposure is located in the S ',SW/&. sec. 2, T. 4 N., R. 10 W. (Marianna, U. S. Geological Survey topographic quadrangle). It is the same locality as Loc. JRL-3-1 but this sample is from the overlying 3 feet of indurated dolomitic limestone. This unit is a tan, indurated to locally sharp, slightly chalky to dense, fossiliferous dolomitic limestone. Vernon (1956, p. 66) referred to this unit as the Byram limestone and Moore (1955, p. 50) did not recognize the Byram but placed the Suwannee limestone directly above the Marianna limestone in his stratigraphic column. Loc. JRL-4 (fig. 13), a road cut on the northeast side of State Highway 73 in the middle of the NW'/i sec. 22, T. 5 N., R. 11 W. (Cottondale East, U. S. Geological Survey topographic quadrangle), exposes 5 feet of light tan to cream, poorly indu- rated, chalky, equigrained, fossiliferous limestone containing 80 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO occasional small irregular nodules of indurated limestone. Approximately 1,000 feet of Marianna limestone is exposed along the highway along the crest of a small hill. The body of limestones extends northeastward from Loc. JRL-4 for one- fourth mile and southwestward for an equal distance, and is overlain by clayey sand and sands of variable thickness. Loc. JRL-5 (fig. 13) is the Marjax Company quarry located on the northeast side of State Highway 73, 1.5 miles northwest of the city of Marianna in the SWI/. sec. 30, T. 5 N., R. 10 W. (Cottondale East, U. S. Geological Survey topographic quadrangle). Here a 30-foot section of Marianna limestone in the company quarry exposes a light reddish tan, poorly indurated, equigrained, chalky, fossiliferous Marianna limestone containing an occasional lens of clay near the surface. The uppermost 1 to 11/ feet of limestone contain a higher magnesium percentage than the underlying exposed rock. The deposit is easily mined with a hydraulic plow and tractor and only occasionally is dynamite used in the operation. The limestone reserves of the company seem quite sufficient. The deposits are conveniently located near both railroad and high- ways. Loc. JRL-6 (fig. 13), on the north side of a graded road, east of St. Johns School, in the NEII.NWi/.SEI. sec. 19, T. 5 N., R. 10 W. (Cottondale East, U. S. Geological Survey topographic quadrangle), exposes 1 foot of cream to light tan, indurated, chalky, equigrained, slightly fissile, blocky, slightly fossiliferous, silty, calcium magnesium shale. Moore (1955, p. 99) suggested that the exposure may be weathered Oligocene or possibly Miocene, and mapped it as Suwannee (1955, pl. I). The exposure is similar to Loc. JRL-3-2, which Vernon (1956, p. 66) placed in the Byram formation. Loc. JRL-7 (fig. 13), on the west side of Bump Nose Road in the SE1/i.NEIi. sec. 19, along the north-south section line (Cottondale East, U. S. Geological Survey topographic quadrangle), exposes a 9-foot section of light cream poorly indurated, chalky, equigrained, fossiliferous Marianna lime- stone. Overlying the limestone is 8 feet of calcium magnesium shale quite similar to that of Loc. JRL-6. This overlying shale was mapped by Moore as Suwannee limestone (1955, pl. I) and is quite similar to what Vernon (1956, p. 66) called Byram. The contact between the Marianna and the Suwannee limestones is at 159 feet. LIMESTONE RESOURCES Loc. JRL-8 (fig. 12), along Bump Nose Road near Marianna in the center of the SEI/. sec. 29, T. 5 N., R. 10 W. (Marianna, U. S. Geological Survey topographic quadrangle), exposes on the northeast flank of a northeast trending topographic nose a 42-foot sloping limestone section. The rock is a light cream, poorly indurated, chalky, equigrained microfossiliferous Marianna limestone. Moore (1955, p. 42) placed the contact between the underlying Crystal River formation and the Marianna limestone at 93 feet (Moore's location J-77). The contact between the Marianna limestone and the overlying Suwannee dolomitic calcium shale is about 127 feet. Loc. JRL-9 (fig. 13), trending northwest-southeast along the Bump Nose Road from the SWI/tSEI/1 sec. 20, T. 5 N., R. 10 W. (Cottondale East, U. S. Geological Survey topographic quadrangle), exposes 13 feet of light tan, indurated, chalky, granular, equigrained, jointed, blocky, slightly fissile, silty, dolomitic calcium shale which was mapped by Moore (1955, pl. I) as the Suwannee limestone. The shale is quite similar to what Vernon (1956, p. 66) called the Byram. The top of the shale is at al elevation of 158 feet and the contact between the shale and the underlying Marianna limestone is 145 feet. In all probability the dolomitic calcium shale is present in the area between Loc. JRL-6 and Loc. JRL-9, where the elevations exceed 145 feet. Loc. JRL-10 (fig. 12), 2 miles northeast of Marianna, Florida, on State Highway 167 in the NI/NEIt sec. 34, T. 5 N., R. 10 W. and the S'/2SE1/. sec. 27, T. 5 N., R. 10 W. (Marianna, U. S. Geological Survey topographic quadrangle), exposes 4 feet of light cream, poorly indurated, massive, equigrained, chalky, fossiliferous Marianna limestone. Overlying the Marianna limestone is 14 feet of alternately nonindurated to indurated, calcium magnesium, silty sandy shale, referred to the Byram formation by Vernon (1956, p. 66) and to the Suwannee by Moore (1955, p. 50). This hill trends roughly northwest- southeast having a length of about 1,600 feet and a width of 800 feet. The general elevation of the Marianna limestone is 100 to 103 feet and nowhere should the overlying material (Suwannee/Byram) exceed much over 14 feet in thickness. Roughly south-southeast of this body is a linear hill trending north-northwest and south-southeast. The hill is approximately 2,600 feet in length and 600 feet wide. The hill was not investigated but the general elevation of the Marianna 82 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO limestone should also be about 100 feet. Disregarding local variations, the overlying shale at most should not exceed 14 feet in thickness. Another roadside exposure of Marianna limestone, 1,000 feet northeastward from Loc. JRL-10, shows the top of the Marianna limestone to be 93 feet above sea level. The top of this section has been somewhat reduced by erosion. Loc. JRL-11 (fig. 12) is a road cut immediately west of the Chipola River bridge on U. S. Highway 90 within the city limits of Marianna. The exposure is located in the center of the SEI/. sec. 3, T. 4 N., R. 10 W. (Marianna, U. S. Geological Survey topographic quadrangle). The sample was taken purely for lithologic, chemical, and structural control. Here the Marianna limestone is a light cream, poorly indurated, chalky, massive, equigrained, fossiliferous limestone. It is overlain by about 3 feet of magnesium bearing shaly limestone called the Byram formation by Cooke (1945, p. 80), and quite similar to what Vernon (1956, p. 66) also called Byram. Moore (1955, pl. I) mapped this exposure as Suwannee limestone. Cooke, when measuring the complete section, found 30 feet of Marianna limestone underlying the Byram and 14 feet of limestone belonging to the Ocala group underlying the Marianna. This exposure is situated in a short east-west road cut through a north-south trending hill whose linear measurement is 2,200 feet. Old chimney rock quarries are located immediately south of the road cut and rock is exposed on the surface northward from the road cut on residential property. Only the vertical exposure in the road cut was measured, and only the Marianna was sampled. Loc. JRL-12 (fig. 16), on the northwest side of a paved county road located in the NWI,/SWI/1 sec. 17, T. 3 N., R. 7 W. (Sneads, U. S. Geological Survey topographic quadrangle), exposes 2 feet of light cream, indurated to poorly indurated, chalky, slightly massive, slightly fossiliferous, slightly silty, clayey, dolomitic limestone belonging to the arenaceous, argillaceous Chattahoochee formation. Loc. JRL-13 (fig. 16) is a good exposure in a ditch, which drains Ocheesee Pond and passes beneath a paved county road in the SEI/tSWI/ sec. 18, T. 3 N., R. 7 W. (Sneads, U. S. Geological Survey topographic quadrangle). Here is exposed a 5-foot section of light tan to light gray, indurated to poorly indurated, LIMESTONE RESOURCES chalky, massive, fossiliferous, silty, clayey, dolomitic limestone belonging to the Chattahoochee formation. It is of interest to note that Loc. JRL-13 and Loc. JRL-12, which are 3,600 feet apart, vary considerably lithologically, though both are of the Chattahoochee formation. Loc. JRL-13 has considerably more clay, silt, and sand and appreciably less calcium carbonate and calcium magnesium carbonate. Loc. JRL-13 is 20 feet lower topographically than Loc. JRL-12, but it would be false to assume that this lithology becomes more arenaceous and argillaceous with depth. This assumption would be incorrect since horizontal as well as vertical lithologic changes are common in the Chattahoochee formation. Loc. JRL-14 (fig. 19), along the east side of the Chipola River, just north of the bridge on a graded road, in the southeastern portion of the NEISEI/. sec. 30, T. 3 N., R. 9 W. (Oakdale, U. S. Geographical Survey topographic quadrangle), exposes about 4 feet of tan, indurated to poorly indurated, chalky, slightly fissile, fossiliferous, silty, dolomitic Suwannee limestone. Though identified and mapped as Suwannee limestone by Moore (1955, p. 56), the exposure is lithologically quite similar to limestone of the Tampa stage. At this locality, the limestone is overlain by about 4 feet of clay, part of which is probably an insoluble residue from the limestone. In the general area, the limestone could be expected at other locations near the same elevation as the exposure. Loc. JRL-15 (fig. 18), beneath a bridge, along an unpaved graded road in the NWI/NEI/t sec. 32, T. 3 N., R. 8 W. (Altha East, U. S. Geological Survey topographic quadrangle), exposes 1 foot of light gray, indurated to poorly indurated, massive, chalky, fossiliferous, silty, dolomitic limestone of the Tampa stage. Moore (1955, p. 65) mentioned that this location, which is his J-131, is unfossiliferous; however, this writer did note the molds of several gastropods. This limestone forms the bed of the branch for over 500 feet. Loc. JRL-16 (fig. 14), a quarry of the West Florida Lime Company just north-northeast of Cottondale, located in the NEI/ sec. 30, T. 5 N., R. 11 W. (Cottondale East, U. S. Geological Survey topographic quadrangle), exposes 20 feet of light reddish tan, indurated to poorly indurated, massive, chalky, equigrained, fossiliferous Marianna limestone. Occasional solution cavities filled with black organic clay are 84 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO encountered near the surface. These are mined out in order to maintain the high purity of the mined product. Loc. JRL-17 (fig. 14) is an unsampled exposure of Marianna lime- stone located 30 feet east of U. S. Geological Survey bench mark 145 on the south side of the Louisville and Nashville Railroad grade, about 400 feet east of the town limits of Cottondale in the NW/lNWI/I. sec. 32, T. 5 N., R. 11 W. (Cottoudale East, U. S. Geological Survey topographic quadrangle). Here is ex- posed 2 feet of a typical Marianna lithology at an elevation of 149.3 feet. This elevation is 13.3 feet higher than a nearby point reported by Moore (1955, p. 50). This variation in elevation attests to the uneven nature of the buried limestone surface. Between Loc. JRL-17 and U. S. Highway 90, there are several exposures included within Area V (fig. 14). These exposures, including Loc. JRL-23 and Loc. JRL-28, lie north, immediately east, and south of the east end of Frank Pond. Here the Marianna limestone is overlain in places by the thin sediments of the Tampa stage. Loc. JRL-18-1 (fig. 15), an old quarry on the north side of an unpaved graded county road in the SEI/.SW1/i. sec. 29, T. 6 N., R. 11 W. (Sills, U. S. Geological Survey topographic quadrangle), exposes 30 feet of light cream to light gray, indurated, chalky, massive, fossiliferous, occasionally coquinoid limestone of the Crystal River formation. This location was quarried some years ago and the more indurated portion has been crushed and used for gravel. Loc. JRL-18-2 (fig. 15) is the same location as Loc. JRL-18-1. This sample represents a more indurated fraction of the mined material which had been set aside in the quarry for future use as gravel. Loc. JRL-19 (fig. 12), an old chimney block quarry located on the west side of State Highway 71 in the SWn'/NW1/i. sec. 30, T. 5 N., R. 9 W. (Marianna, U. S. Geological Survey topographic quadrangle), exposes 21 feet of light cream, indurated to poorly indurated, chalky, massive, equigrained Marianna limestone. Loc. JRL-20 (fig. 12), a northeast-southwest trending hill on the west side of an unpaved graded county road on the east side of the Chipola River, just east of the town of Marianna, located in the center of the N/i. of sec. 2, T. 4 N., R. 10 W. (Marianna, U. S. Geological Survey topographic quadrangle), LIMESTONE RESOURCES exposes a few feet of light cream, indurated, chalky, equigrained, massive, fossiliferous Marianna limestone. This hill is roughly 2,500 feet long and 1,600 feet wide. The hill is in all probability underlain by limestone though masked by sand and clayey sand. Though no dolomitic limestone exposures were noted, the Marianna limestone is probably overlain by a dolomitic limestone as mentioned in Loc. JRL-10 and Loc. JRL-11. The Marianna is underlain by Crystal River formation as noted under Loc. JRL-11. Loc. JRL-21-A (fig. 13) is a quarry not in operation at the present and owned by Mr. Sam Smith. The quarry is located on the north side of State Highway 73, 3 miles northwest of Marianna. In about the center of sec. 23, T. 5 N., R. 11 W. (Cottondale East, U. S. Geological Survey topographic quadrangle). Here is exposed a maximum of 40 feet of light cream, indurated to poorly indurated, chalky, massive, equigrained, fossiliferous Marianna limestone. The Marianna limestone is overlain by a thin veneer of clay and clayey sand and underlain by the Crystal River formation. Loc. JRL-21-B (fig. 13) is the same area as Loc. JRL-21-A, but represents the exposed 14 feet of Crystal River formation which underlies the Marianna. The Crystal River formation is a light cream to white, poorly indurated to indurated, chalky, fossiliferous limestone containing locally dense and locally coquinoid bodies. Moore (1955, p. 37) gives a measured geologic section of this locality in which he includes his Bumpnose member of the Crystal River formation. The general area has large reserves of high grade calcium carbonate, along with a minor amount of harder rock suitable for gravel. Loc. JRL-22 (fig. 20) is a dry stream valley on the ranch of Leland Thomas, 1 mile south of U. S. Highway 90 and 2.6 miles east of Cottondale in the NEI/NWI/. sec. 10, T. 4 N., R. 11 W. The valley continues southwestward to the center of the W/. of the same section (Cottondale East, U. S. Geological Survey topographic quadrangle). The exposure is a light cream to white, poorly indurated, chalky, massive, equigrained Marianna limestone. Loc. JRL-22 is on the east valley edge, on the east-west section line between the SEM/.SW/W1. sec. 3, T. 4 N., R. 11 W., and the NEI/NWI/& sec. 10, T. 4 N., R. 11 W. Moore (1955, pl. I) shows the Marianna in this locality to be overlain by Suwannee limestone, but with the exception of the valley 86 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO edges where the rock is exposed, limestones are masked by a veneer of sands and clayey sands. The above valley continues southwestward into the SE1/, sec. 9, T. 4 N., R. 11 W., where it joins another similar valley which trends north-northwest and south-southeast. At the junction of the two valleys, the exposures continue southeasterly for a short distance. The westward valley is reported by Mr. Leland Thomas (personal communication) to have exposures similar to that of the eastern valley. Loc. JRL-23 (fig. 14) is an unsampled location of rock exposed in a field in the SWI/NWI/t sec. 32, T. 5 N., R. 11 W., about 500 feet southeast of Frank Pond, just east of Cottondale (Cotton- dale East, U. S. Geological Survey topographic quadrangle). This location is part of the general area discussed under Loc. JRL-17. Loc. JRL-24 (fig. 20) is an exposure not visited by the author but according to Mr. Leland Thomas of Cottondale (personal communication), limestone is exposed in a large sink located in the center of the WI/.2SE!/. sec. 10, T. 4 N., R 11 W. (Cottondale East, U. S. Geological Survey topographic quadrangle). Loc. JRL-25 (fig. 15), and old "chimney block" quarry in the SWI/ISEi/iNWI/i. sec. 32, T. 6 N., R. 11 W. (Sills, U. S. Geological Survey topographic quadrangle), exposes light cream to light gray, indurated, chalky, massive, fossiliferous Crystal River formation. The exposure is on the flank of a small hill located 1,400 feet southwest of Loc. JRL-26. Loc. JRL-26-1 (Fig. 15), an old rock quarry currently not operating, located roughly 0.7 mile east of U. S. Highway 231 and 7 miles north of Cottondale in the SEI5 NEI/NWi'/ sec. 32, T. 6 N., R. 11 W. (Sills, U. S. Geological Survey topographic quadrangle), exposes 28 feet of white to light gray, poorly indurated to indurated, chalky, massive, fossiliferous limestone of the Crystal River formation having well indurated zones and coquinoid zones. The quarry is quite extensive but currently it is somewhat overgrown. The short channel sample taken extended from 105 to 107 feet. Loc. JRL-26-2 (fig. 15) is the same quarry as Loc. JRL-26-1. The short channel sample taken extended from 120 to 122 feet. Loc. JRL-27 (fig. 15), a rock quarry currently not operating, located one-half mile southeast of Loc. JRL-26-1 in the LIMESTONE RESOURCES NEI/tSEI/t sec. 32, T. 6 N., R. 11 W. (Sills, U. S. Geological Survey topographic quadrangle), exposes 31 feet of white to light gray, poorly indurated to indurated, chalky, massive, fossiliferous limestone of the Crystal River formation having local coquinoid zones and localized well indurated zones on the surface and at depth. A cave having its entrance on the upper northern face of the quarry is noteworthy since it contains stalactites and stalagmites. Loc. JRL-28 (fig. 14), along U. S. Highway 90, located in the NWI/SESI/ sec. 32, T. 5 N., R. 11 W. (Cottondale East, U. S. Geological Survey topographic quadrangle), exposes a few feet of cream to tan, indurated to poorly indurated dolomitic shaley limestone whose top is at an elevation of 146 feet. Lower in the section at an elevation of about 142 feet, the limestone be- comes softer and lighter in color. Moore (1955, pl. I) maps the Marianna-Suwannee limestone formational contact as occurring near this lithologic change. The upper shaley zone is lithologically quite similar to some of the beds of the Byram formation which Vernon (1956, p. 66) described, and the lime- stone below the contact is Marianna. No analysis of either limestone is available. Loc. JRL-29 (fig. 13), a roadside exposure located on the north side of State Highway 73, in the southeast corner NWSI/ sec. 25, T. 5 N., R. 11 W. (Cottondale East, U. S. Geological Survey topographic quadrangle), exposes an impressive section of the Crystal River formation and Marianna limestone. Here hidden from roadside view is a 40-foot section which is listed in the Southeastern Geological Society Guidebook of the Third Field Trip (1945, p. 16) as Stop No. 7. Moore (1955, p. 49) lists this location as Loc. J-74. The elevation of the top of the exposure is 135 feet and the lowermost exposed rock is 95 feet. The elevation of the contact between the older Crystal River formation and the Marianna limestone is 105 feet. No analysis is available of either limestone at this location, but the Crystal River should be expected to contain about 97 to 98 percent calcium carbonate, with traces of magnesium carbonate, silica, iron and clay. The Marianna will not be quite as pure as the Crystal River, but nonetheless it should contain about 95 percent calcium carbonate along with slightly more magnesium carbonate, silica, iron and clay. Analysis of other limestones in this area (Area IV) will serve as an index to the chemical composition of this exposure. 88 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO Loc. JRL-30 (fig. 17), along a paved county road south of Sneads, in the N!/ANWi/I.NWI/. sec. 3, T. 3 N., R. 7 W. (Sneads, U. S. Geological Survey topographic quadrangle), exposes a few feet of white, poorly indurated, pasty, chalky, silty limestone of the Chattahoochee formation. The top of the limestone exposure is at 108 feet above sea level. No analysis is available for the limestone at this location but it would probably be quite similar to that of Loc. JRL-12. Loc. JRL-31 (fig. 17), Moore's J-112, along a paved county road south of U. S. Highway 90, in the approximate center of sec. 36, just north of the Louisville and Nashville Railroad crossing (Sneads, U. S. Geological Survey topographic quadrangle), exposes about 2 feet of white, indurated to poorly indurated, silty, fossiliferous limestone of the Chattahoochee formation. Moore (1955, p. 64) places the elevation of the top of the exposure at 135 feet, but this elevation is in error. The elevation was found by this author to be 100 feet. Nowhere in the immediate area do the elevations of the land surface get much over 120 feet. No analysis of Loc. JRL-31 is available but the analysis will be similar to that of Loc. JRL-12 and 13. Loc. JRL-32 (fig. 17), located on the escarpment bordering the west bank of the Apalachicola River near the water discharge canal at the steam power plant located in the SEI!SWI/i sec. 12, T. 3 N., R. 7 W., exposes 10 or more feet of light gray, indurated to poorly indurated, silty, fossiliferous limestone of the Chattahoochee formation. The top of the limestone at this location is 75 feet above sea level. This formation should be exposed or have a thin cover at additional points northward and southward from this location along the Apalachicola River escarpment at elevations of 75 feet or higher. Additional exposures were not sought after by the author but nevertheless the economic potential of this area is very good. No analysis is available for Loc. JRL-32. Loc. JRL-33 (fig. 17), at the northeast corner at the intersection of two graded roads at the southwest corner of SW1/I.NW1/I. sec. 11, T. 3 N., R. 7 W. (Sneads, U. S. Geological Survey topographic quadrangle), exposes a bare surface of light cream, poorly indurated, silty, nodular limestone of the Chattahoochee formation. The elevation of the top of the exposure is 110 feet. Though no analysis of Loc. JRL-33 is available, the analysis would be similar to that of Loc. JRL-12 and 13. LIMESTONE RESOURCES LIMESTONE AS AN ECONOMIC DEPOSIT GENERAL DEFINITION Limestone is formed through the chemical or biochemical pre- cipitation of calcium carbonate or by the accumulation of calcareous shells as a bedded sediment in marine or fresh waters. Varying quantities of other substances, such as magnesium carbonate, silica, clayey material, salts or iron and organic matter, may be present as impurities. Calcareous materials are consoli- dated gradually into rock by compaction, dehydration and crystallization. Through long geologic ages of mass adjustment these deposits eventually become available for commercial use (Bowles, 1941, p. 5). The "Glossary of Geology and Related Sciences" (AGI 1957, p. 169) defines limestone as: "1. ... a bedded sedimentary deposit consisting chiefly of calcium carbonate (CaCO,,) which yields lime when burned . Limestone is the most important and widely distributed of the carbonate rocks and is the consolidated equivalent of limy mud, calcareous sand, or shell frag- ments (Stokes and Varnes, 1952, p. 83-84). "2. . a general term for that class of rocks which contain at least 80 percent of the carbonates of calcium or magnesium .... The suitability of the rock for the manufacture of lime is not an essential characteris- tic (Pettijohn, 1949, p. 289)." The essential chemical constituent of limestone is calcium carbonate (CACO::), the mineral calcite. Many commercial occurrences designate "high-calcium" limestone as that which contains 93 to 97 percent calcium carbonate. When other substances occur in the stone, it is classed according to the nature of the impurities. An increasing percentage of dolomite in a specimen alters the proper name of a limestone. A limestone must contain less than 5 percent dolomite and greater than 95 percent calcite. A magnesium limestone contains greater than 5 and less than 10 percent dolomite and greater than 90 and less than 95 percent calcite. A dolomitic limestone contains greater than 10 and less than 50 percent dolomite and greater than 50 and less than 90 percent calcite. A calcitic dolomite contains greater than 50 and less than 90 percent dolomite and greater than 10 and less than 50 percent calcite. Dolomite contains greater than 90 percent dolomite and less than 10 percent calcite. Argillaceous limestone contains a considerable proportion of clay consisting mainly of hydrous aluminum silicates. Siliceous, cherty or arenaceous varieties 90 FLORIDA GEOLOGICAL SURVEY-BULLETIN FORTY-TWO of limestone contain considerable silica. Ferruginous limestone has considerable iron content and colors the rock shades of brown and red. Carbonaceous or bituminous material within a limestone imparts a dark gray or black color to the rock. Other varieties of limestone are based upon texture of physical characteristics. Compact limestone is a fine grained, dense, homogeneous rock which may range in color from white to black. The degree of induration is the degree to which the hardening of rock materials has progressed, through cementation, pressure, heat or other causes (AGI, 1957, p. 148). Oolitic limestone is composed of small, rounded grains of calcium carbonate with a concentrically laminated structure. Some limestone beds have been formed under conditions that left many shells almost intact or at least in frag- ments sufficiently well preserved to indicate their origin and character. These are known as fossiliferous limestones. Some of them are made up almost entirely of shells of one kind and all may be termed coralline limestone, crinoidal limestone, or coquina. Unconsolidated oyster shell beds are closely related to fossiliferous limestone and may be quite extensive. Oyster shell is a very pure form of calcium carbonate that occurs in commercial quantities. Uniformity and purity of lime made from shell beds of oysters is outstanding. Though large beds of oyster shells are few, they should not be overlooked as a potential source as a raw material. Cherty limestones contain nodules and or bands of chert or flint (Bowles, 1941, p. 6). The common impurities in limestone are clay, which contains silica and alumina; sand or other forms of free silica; iron oxide; iron carbonates, sulfides of iron, gypsum; alkali salts; and carbonaceous material. Clay is found most often along the bedding planes and is also frequently found disseminated throughout the rock. Silica occurs in limestones as nodules or masses of chert (flint), and may be present in varying amounts. If concentrated, the siliceous mass may be pure chert; where only slightly con- centrated, the limestone will have the outward appearance of limestone but will be saturated with silica. Silica also occurs as grains of sand, silt, or finer size material. Iron compounds are not only deposited with the calcium carbonate during the initial period of sedimentation, but are also brought in by percolating ground waters. These iron compounds are also formed by the chemical reaction with other minerals. Sulfur may be present in combination with iron as pyrite or marcasite, and in gypsum so that under ordinary conditions it is not free. However, these sulfides are easily oxidized. Small quantities of the alkalies, soda LIMESTONE RESOURCES and potash, are present in some limestones, probably in the form of carbonates or in the clay impurities as silicates. Impurities are noted in greater proportions in weathered rock than in unweathered rock because the soluble components have been leached out (Bowles, 1941, p. 7). Bowles (1941, p. 7) stated that impurities in limestones have various effects on the properties of limes. Small amounts of silica tend to decrease plasticity, sand carrying capacity, and yield of lime, but have no apparent effect on its hardness or strength. Silica in the form of chert or flint occurring in limestone is not suitable for the manufacture of lime unless the chert can be separated and removed at very little expense. If clay, an aluminum silicate mineral, is present in certain proportions in the limestone, and the limestone is then calcined to lime, a product is produced (hydraulic lime) that when mixed with water has the property of setting or otherwise forming a firm strong mass under water. For making lime itself if silica is present in excess of four or more percent, the limestone is rarely suitable for making lime. Iron present in a burned limestone has much the same effect as silica, except that lime containing large amounts of iron is much stronger and harder. Kaolinite seems to act in a manner similar to silica and iron. Gypsum shows detrimental effects, even when only 1 percent is present. Moderate amounts of carbonaceous material are not retained in the lime as they are consumed during calcination. Magnesium limestone may embrace several varieties texturally, and if physically and chemically suitable may be burned to lime. The product will therefore be a mixture of calcium oxide and magnesium oxide. USES GENERAL The following discussion on the uses of limestone has been compiled for general use with regard to the limestones of Wash- ington, Holmes and Jackson counties, Florida, and by no means is it intended to be a treatise on the uses of limestone. Study on the uses of limestone must be supplemented by standard texts and various specific publications. In general, the uses of limestone may be classified into two groups: "chemical uses" in which the chemical composition of limestone is of dominant importance; and "physical use" in which the physical characteristics of the limestone is of dominant |
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| MILLISECOND | CLASS.METHOD | MESSAGE |
|---|---|---|
| 0 | sobekcm_page_globals.constructor | |
| 0 | sobekcm_page_globals.constructor | Application State validated or built |
| 0 | sobekcm_database.verify_item_lookup_object | |
| 0 | sobekcm_page_globals.constructor | Navigation Object created from URI query string |
| 0 | sobekcm_database.verify_item_lookup_object | |
| 0 | sobekcm_page_globals.display_item | Retrieving item or group information |
| 0 | sobekcm_page_globals.get_entire_collection_hierarchy | Retrieving hierarchy information |
| 0 | sobekcm_assistant.get_entire_collection_hierarchy | |
| 0 | cached_data_manager.retrieve_item_aggregation | |
| 0 | cached_data_manager.retrieve_item_aggregation | Found item aggregation on local cache |
| 0 | item_aggregation_builder.get_item_aggregation | Found 'all' item aggregation in cache |
| 0 | system.web.ui.page.page_load (ufdc.page_load) | |
| 0 | sobekcm_page_globals.constructor.on_page_load | |
| 0 | html_echo_mainwriter.add_style_references | Adding style references to HTML |
| 0 | html_echo_mainwriter.add_text_to_page | Reading the text from the file and echoing back to the output stream |
| 53 | html_echo_mainwriter.add_text_to_page | Finished reading and writing the file |