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Stratigraphy and sedimentary history of Newnans Lake

HIDE
 Title Page
 Acknowledgement
 Table of Contents
 List of Figures
 List of Tables
 List of abbreviations and common...
 Abstract
 Introduction
 Methods of study
 Present sedimentation
 History of sedimentation
 Conclusions
 Appendix
 Bibliography
 Biographical sketch
 
Page 1 of 2


Cathleen Martyniak

From: Dan Spangler [dspangle@geology.ufl.edu]
Sent: Monday, July 07, 2008 11:42 AM
To: Cathleen Martyniak
Cc: george griffin
Subject: Re: student from 1976

CATHY, I DON'T BELIEVE MR. HOLLY HAD ANY CHILDREN AS HE AND HIS WIFE SEPARATED NOT
LONG AFTER HE GRADUATED. SHE MOVED TO ARIZONA OR NEW MEXICO WHERE SHE WAS
ORIGINALLY FROM I BELIEVE, AND I'M NOT SURE OF HER NAME, ADDRESS, OR IF THEY LATER
REUNITED??. IN ANY EVENT, MR. HOLLY'S THESIS ADVISOR WAS DR. GRIFFIN(HE IS COPIED OFF IN
THIS EMAIL). JIM'S MAIN INTEREST HAVING WORKED IN FLORIDA FOR THE USGS AND MY CLASSES IN
WATER, WAS AS A HYDROGEOLOGIST. I PERSONALLY HAVE NO QUALMS REGARDING HIS THESIS ON
THE INTERNET, BUT YOU MIGHT CONTACT DR. GRIFFIN(NOW RETIRED ALSO), AND THE CURRENT
CHAIRMAN OF THE UF GEOLOGY DEPT(DR. MICHAEL PERFIT) FOR OTHER INPUT AND THOUGHTS.
GOOD LUCK, AND I THINK JIM WOULD BE PROUD OF YOUR THOUGHTS AND WORK. DAN SPANGLER

----- Original Message -----
From: Cathleen Martyniak
To: Dan Spangler
Sent: Monday, July 07, 2008 10:54 AM
Subject: RE: student from 1976

Dr. Spangler,

Oh dear. I am so sorry to hear he is gone. Do you know if he had any children? I would like to, somehow, get
permission to post his thesis on the Internet.

Cathy


From: Dan Spangler [mailto:dspangle@geology.ufl.edu]
Sent: Wednesday, July 02, 2008 8:51 AM
To: Cathleen Martyniak
Subject: Re: student from 1976

Good Morning Cathleen: Unfortunately Mr Holly passed away several years ago(I believe in Arizona). His
parents did have a home place in Ocala National Forest, but I don't believe either is alive. Jim was a great
student, and I always believed his thesis led to some good current work at the Florida Museum in Palynology. If
I can be of further assistance, please don't hesitate to do so. Thanks, Dan Spangler
----- Original Message -----
From: Cathleen Martyniak
To: dspangle@geology.ufl.edu
Sent: Tuesday, June 10, 2008 1:46 PM
Subject: student from 1976

Dr. Spangler,

Hello. My name is Cathy Martyniak. I work at the UF Libraries. I am trying to track James B. Holly, a Masters
student from 1976. His thesis was on Newnans Lake. I don't suppose you have kept track of him by any
chance?

Thanks,


8/12/2008




Permanent Link: http://ufdc.ufl.edu/UF00090222/00001

Material Information

Title: Stratigraphy and sedimentary history of Newnans Lake
Series Title: Stratigraphy and sedimentary history of Newnans Lake
Physical Description: Book
Creator: Holly, James Benjamin,

Record Information

Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000178678
oclc - 03125299
System ID: UF00090222:00001

Permanent Link: http://ufdc.ufl.edu/UF00090222/00001

Material Information

Title: Stratigraphy and sedimentary history of Newnans Lake
Series Title: Stratigraphy and sedimentary history of Newnans Lake
Physical Description: Book
Creator: Holly, James Benjamin,

Record Information

Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: alephbibnum - 000178678
oclc - 03125299
System ID: UF00090222:00001

Table of Contents
    Title Page
        Page i
    Acknowledgement
        Page ii
    Table of Contents
        Page iii
        Page iv
    List of Figures
        Page v
        Page vi
    List of Tables
        Page vii
    List of abbreviations and common names
        Page viii
        Page ix
        Page x
    Abstract
        Page xi
        Page xii
    Introduction
        Page 1
        Page 2
        Page 3
    Methods of study
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
    Present sedimentation
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
    History of sedimentation
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
        Page 44
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
    Conclusions
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
    Appendix
        Page 58
        Page 59
        Page 60
        Page 61
        Page 62
        Page 63
        Page 64
        Page 65
        Page 66
        Page 67
        Page 68
        Page 69
        Page 70
        Page 71
        Page 72
        Page 73
        Page 74
        Page 75
        Page 76
        Page 77
        Page 78
        Page 79
        Page 80
        Page 81
        Page 82
        Page 83
        Page 84
        Page 85
        Page 86
        Page 87
        Page 88
        Page 89
        Page 90
        Page 91
        Page 92
        Page 93
        Page 94
        Page 95
        Page 96
        Page 97
        Page 98
        Page 99
    Bibliography
        Page 100
        Page 101
    Biographical sketch
        Page 102
        Page 103
Full Text













STRATIGRAPHY AND SEDIMENTARY HISTORY OF NEWNANS LAKE


BY

JAMES B. HOLLY








A THESIS PRESENTED TO THE GRADUATE COUNCIL
OF THE UNIVERSITY OF FLORIDA
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
DEGREE OF MASTER OF SCIENCE





UNIVERSITY OF FLORIDA


1976













ACKNOWLEDGMENTS


I would like to express my appreciation to Dr. George M. Griffin

for his time, help and patience and for the use of his laboratory and

equipment; and to Dr. Daniel P. Spangler for his time and encourage-

ment and for the use of his office space.

Additional acknowledgments are made to Dr. Edward S. Deevey, Jr.

for his helpful suggestions and discussions of pollen and limnology;

to Mr. Hague Vaughn for his help in pollen grain identifications; to

Ms. Jo Ann Salter for typing the thesis; and to all the other people

at the University of Florida who have been helpful in answering

questions and discussing problems.


ii

















TABLE OF CONTENTS


Page


ACKNOWLEDGMENTS . . . . . .


11


LIST OF FIGURES . . . . . . . . . . .

LIST OF TABLES . . . . . . . . . . .

LIST OF ABBREVIATIONS AND COMMON NAMES . . . . .

ABSTRACT . . . . . . . . . . . . .

INTRODUCTION . . . . . . . . . . . .


viii


1


METHODS OF STUDY . . . . . .

Field Methods . . . . .
Location and Numbering of Sampl
Grab Samples . . . .
Core Samples . . . . .
Soil Samples . . . . .
Depth-Recorder Traverses .
Laboratory Methods . . . .
Physical Description of Cores
Water Content Loss on Ignition
Sand Content . . . . .
Sieve Samples . . . . .
Silt Fraction . . . . .
Diatoms and Sponge Spicules .
Detrital Silt . . . . .
Reworked Amorphous Silica .
Pollen Counts . . . . .
Charcoal Fragments . . .

PRESENT SEDIMENTATION . . . .

Lake Sediments . . . . .
Soil Samples . . . . .
Summary . . . . . . .

HISTORY OF SEDIMENTATION . . .

Pollen Diagram . .. . . .
Charcoal Fragments . . . ..


. . . . . 4

. . . . . 4
s . . . . 4
. . . . . 4
. . . . . 6
. . . . . 7
. . . . . 7
. . . . . 7
. . . . . 7
. . . . . 7
. . . . . 8
. . . . . 8
. . . . . 8
. . . . . 10
. . . . . 11
. . . . . 11
. . . . . . 11
. . . . . 12
s4

















12










Page
Sand . . . . . . . . ... .. . . 42
Silt ......... . . . . . . . . . 42
Diatoms . . . . . . . . . . . 43
Sponge Spicules . . . . . . . ... . 44
Gross Variations in Sediment Types . . . ... 45
Cross Section . . . . . . . .... . 45

CONCLUSIONS . . . . . . . . ... .. . . 51

APPENDIX ...... . .. . .... ....... . 58

BIBLIOGRAPHY .. . . . . . . . .. ... 100

BIOGRAPHICAL SKETCH . . . . . . . .... 102













LIST OF FIGURES


Figure

1. Map of Newnans Lake showing locations of samples


Page

5


2. Areal distribution of sand percentages in
surficial Newnans Lake sediments . . . .. .. . 14

3. Areal distribution of ash percentages in
surficial Newnans Lake sediments . . . . ... 15

4. Depth contour map of Newnans Lake . . . . .... 16

5. Lithologic logs of cores from Newnans Lake .. . ... .17

6. Lithologic logs of soil auger samples from
the vicinity of Newnans Lake . . . . . . . 22

7. Composition of Newnans Lake sediments
as represented in ternary diagrams . . . . . .. 25

8. Arithmetic plot of sand content and organic
content for surficial sediments from Newnans Lake . .26

9. Lithology, water content, loss on ignition,
sand content, and charcoal fragments in
,core 012376 1300 . . . . . . . . . . 32

10. Arboreal pollen diagram for core 012376 1300 ...... 34

11. Nonarboreal pollen diagram for core 012376 1300 .... .36

12. Lithology, water content, loss on ignition, sand
content, and charcoal fragments in cores 012376
1300, 092775 1625, and 102375 1600 . . . . . .. 37

13. Arboreal pollen diagram for cores 012363 1300,
092775 1625, and 102375 1600 . . . . . . .. 39

14. Nonarboreal pollen diagram for cores
012376 1600, 092275 1625, and 102375 1600 . . . .. 41

15. Distribution of silt grains and diatoms
in core 012376 1300 . . . . . . . . . 47










Figure


Page


16. North-south and east-west cross sections
of Newnans Lake . . . . . . . . . 49

17. Graph showing the relationship between
NAP and sand content in core 012376 1300 -. ... ... 56














LIST OF TABLES



Table Page

1. Sieve analyses for selected sand samples
from Newnans Lake .................. 9

2. Pollen grain counts ................. 59

3. Composition of silt fractions . . . . .... .86

4. Sand: sieve analyses ... .. . . . . . 92

5. Percent water, ash, and sand . . . . .... .96






























vii













LIST OF ABBREVIATIONS
AND COMMON NAMES

Pollen:

AP. Arboreal pollen; pollen from plants making up the forest

canopy: trees and shrubs.

NAP.Nonarboreal pollen; pollen from herbs,-grasses and weeds.


Latin and Common Names:

Acer. maple

Amaranthus type. pigweed, lamb's quarter, red amaranth, etc.

Ambrosia. ragweed

Artemisia. wormwood

Carpinus type. hornbeams and hophorm beams

Carya. hickory

Cyperaceae. sedges

Ericaceae. heath, blueberries, huckleberries, etc.

Fraxinus. ash

Graminae. grasses

Ilex. holly

Liquidambar. sweet gum

Myrica. bayberry, waxmyrtle, etc.

Nuphar. water lily

Nympheae. water lily

Nyssa. tupelo and black gum

Pinus. pine

Querus. oak

Salix. willow


viii









Taxodium. cypress

Tubuliflorae. subdivision of Compositae

Ulmus. elm


Sediment Parameters:

Md--Median diameter (Folk, 1974)

M --Graphic mean (Folk, 1974)

oa--Inclusive graphic standard deviation (Folk, 1974)

SkI--Inclusive graphic skewness (Folk, 1974)
k --Graphic kurtosis (Folk, 1974)

0--Phi diameter; the negative logarithm to the base 2 o

the diameter in millimeters.

Organic matter--for the purpose of this paper, a synonym

loss on ignition at 550C

Inorganic matter--ash remaining after ignition at 550C


f


m of


General:

%--percent

#--number

cm--centimeter

g--grams

ft--feet

C--Celsius, Centigrade

B.P.--Before present

SE--southeast

PVC--polyvinylchloride

USGS--United States Geological Survey








cps--cycles per second
KOH--potassium hydroxide
msl--mean sea level
r--correlation coefficient





Lithologic Symbols


I


\>


Peat


Gyttja


Organic sediments (peat, gyttja)


Organic debris


Sand


Clay











Abstract of Thesis Presented to the Graduate Council of the
University of Florida in Partial Fulfillment of the Requirements
for the Degree of Master of Science

STRATIGRAPHY AND SEDIMENTARY HISTORY OF NEWNANS LAKE

By

James B. Holly

December, 1976

Chairman: G. M. Griffin
Major Department: Geology


The sediments of Newnans Lake, north-central Florida, were studied

both really, to determine the nature of presently forming sediments

and vertically from a series of cores, to attempt to interpret the

past history of the lake.

Really the lake sediments show higher sand concentrations and

lower organic material near shore, a relationship which changes

rapidly away from shore. The lake basin is largely filled with gyttja,

which is underlain in the center of the lake by clay and in more

nearshore areas by a blanket of sand overlying the clay. The sand is

well sorted and probably represents present and relict shore line

deposits.

The vertical distribution of sediments shows several sand influxes

into the lake. These changes in sand concentration are paralleled by

changes in other sediment parameters such as the composition of the

silt fraction, the diatom assemblage, and by variations in the pollen

diagram. The interrelationships of the various sediment parameters

suggest that the parts of the cores showing high sand concentrations

xi









represent times of lowered lake level and a reduction in rainfall.

The lake appears to have begun as a grass marsh or other shallow

water body which was accumulating silt and clay rich organic sediment.

After this period of time, the area developed rapidly into an open

water lake which became eutrophic very early. The last stage of

development of the cypress swamp indicates little change from present

conditions.

Based on pollen correlations with other, previously studied,lakes:

Newnans Lake appears to be between 5000 and 8009 years old.













INTRODUCTION


Newnans Lake is situated in north central Florida about three

miles east of Gainesville. There are two creeks discharging into the

lake at the north end: Hatchet Creek and Little Hatchet Creek. Neither

of the creeks has a definite channel where it enters the lake but

rather both diffuse into the cypress swamp. Prairie Creek carries

water from Newnans Lake south into the Paynes Prairie area. The lake

is fringed by cypress which is most extensive at the northern end.

At present there is little development, either agricultural or urban,

around the lake.

The U. S. Geological Survey has maintained a gaging station on

Newnans Lake since 1936. According to their records, the maximum

lake level was 71.21 feet above mean sea level (msl) on March 12,

1948, and the minimum was 63.87 feet msl on May 19, 1962. Prior to

1966 the lake showed a fluctuation range of about four feet. In 1966

a control (dam) was constructed on Prairie Creek at highway 20 which

reduced the overall water level fluctuations. The control was removed

early in 1976, but reinstated about 6 months later at a slightly lower

elevation.

Cooke and Mossom (1929) show Newnans Lake as surrounded by sedi-

ments of the Hawthorne Formation on the west, north and east with

Ocala Limestone to the south extending into the Paynes Prairie area.

Cooke (1945), Vernon (1964), and Clark et al. (1964) also show this

same relationship with the exception that Vernon and Clark et al. use









the term Ocala Group rather than Ocala Limestone. Clark et al. (1964)

indicate that the elevation of the top of the Ocala Group is near

mean sea level at the south end of the lake but declines to more than

180 feet below mean sea level at the north end of the lake.

Cooke (1945) described the Wicomico and Penholoway shoreline

deposits in the area. These are based purely on elevation relationships.

The area surrounding Newnans Lake would fall in the area of the Wicomico

deposits (70-100 feet). Cooke however, states that limestone solution

may have reduced the elevations. MacNeil (1950) shows Newnans Lake

as an embayment into the Wicomico (100 foot) shoreline. Other authors

have used different terminology and elevations for terrace deposits in

the area. Vernon (1951) and Pirkle et al. (1970) present summaries of

these.

Most authors assign the terrace deposits to the Pleistocene.

Alt and Brooks (1965) assign a 90 to 100 foot sea level stand to the

Pliocene and a 70 to 80 foot stand to the Pliocene of Pleistocene.

They further note that the 90 to 100 foot shore line is in an

advanced state of karst erosion.

White (1970) and Puri and Vernon (1964) place the Newnans Lake

area in the Alachua Lake Cross Valley which connects the Western

Valley to the Central Valley regions and forms an embayment into the

Northern Highlands.

Davis (1946) describes the organic sediments of Newnans Lake

as ". .. 4 to 6 feet of dark gray, sandy gyttja which has nearly

filled the lake. This sediment is 73 percent.ash and, therefore,

not a peat but a sandy muck." Davis also gives a cross section of








nearby Mud Lake, after E. C. Roe. Included in Davis' paper is a

pollen analysis of peat samples from wells and cores. He interprets

the past climate on the basis of.these as having been cooler with a

lower sea level, possibly during the late Wisconsin glacial age,

followed by a warmer climate and a higher sea level.

Watts (1969) presents a pollen diagram and analysis for a 1360 cm

core in Mud Lake, which is located about 40 miles SE of Newnans Lake,

in Marion County. He divides the diagram into six zones, the oldest

dating back possibly to the Illinoian glaciation. Watts interprets

the last 8260 years to have began with a period in which the lake was

probably dry due to lowering of the water table as a result of lowered

sea level. From 8260 to 5070 years ago (zone M2) the lake was a
"grass swamp" surrounded by dry oak forest or scrub. The last 5070

years (zone Ml) is interpreted as showing little change from its

present status as a shallow, cypress fringed lake.

Gleason, et al. (1974) present evidence for periods of severe

droughts in Florida, based on a study by H. K. Brooks in Marion

County. These dry periods are presented as four zones: (1) 4030

years B.P., (2) subsequent to 3830 years B.P. and prior to 3620

years B.P., (3) 2970 years B.P., and (4) subsequent to 2900 years B.P.













METHODS OF STUDY


Field Methods


Location and Numbering of Samples

Lake samples were located by obtaining horizontal angles between

known points on the shore with a sextant. Samples taken on the shore

were located by use of a topographic map.

All sample numbers for samples taken in this study consist of

the date and time that the sample was taken (e.g. December 12, 1975

at 4:00 p.m. would be number 121275 1600). Core samples are further

subdivided by the depth in centimeters.

Well logs used are referred to by the latitude and longitude as

assigned by Suwannee River Water Management District, or in the case

of State Road Department, by the suffix SRD and the date drilled.

Grab Samples

Grab samples were taken with a Peterson-type grab sampler and in

a few instances by use of 1 1/2-inch PVC pipe to take a short core

of the surface sediment. The disadvantage of the grab sampler is that

the heavy sampler tends to sink below the surface of the soft organic

sediments, and the samples probably do not represent the true nature

of the top (presently forming) sediments. However, comparison with

the top sediments from cores in the same area does show consistent

trends.




















































. 1'


0 *o0904760o00
0o0o476 0o50
'0*0O047 0830


I A


I ~-I- I




-SWAMP OR MA..R5
SAMPLE LOCATIONS *CORE SAMPLES
/' --- ATHOMETEC TRAVERSES
S ~l-, A --A CROSS SECTION
1 05 0 I MILE
1 05 0 1 ILOMETE
SCAIE


Figure 1. Map of Newnans Lake showing locations of samples.


)r









Core Samples

Cores were taken by means ofa piston corer suspended from a tripod

mounted on the back of a boat. The cores were collected in 1 1/2-inch

thin wall PVC tubing.

The piston corer was used in an effort to obtain cores with little

deformation and compaction. Unfortunately, the upper part of the

sediment is quite aqueous ("false bottom") and is both easily disturbed

and difficult to detect; a sounding weight sinks into the aqueous

sediment as much as two feet before stopping. Probably as a result of

this (or possibly due to some other disturbance) the top of 092775-1625

seems to be missing or disturbed as judged from the pollen diagram.

Even though a light sounding weight with a large diameter was lowered

to accurately determine the top of the sediment before coring, pitching

of the boat created some doubt as to the absolute undeformed nature of

the topmost sediments.

The only other difficulty encountered was when the rope holding

the piston stretched on core 102375 1400,compressing the total length

of the core from 12 to 8 feet (360 to 240 cm). No analyses other than

physical description were used on this core. Aside from these dif-

ficulties the cores are thought to be quite adequate.

At site 102375 1400 a wash boring was made to determine if another

organic layer was present under the clay penetrated by the core. At

a depth of 30 feet below the lake surface (13 feet of water plus 17

feet of sediment) only grey clay was encountered.

The cores were opened by grooving both sides of the core liner

with a circular saw fitted with a masonry blade, and then carefully





7


splitting the core and liner lengthwise with a knife. Both operations

were performed while the core was securely held on a core splitting

table constructed for this purpose. This provided a cross section of

the core which could be readily described.


Soil Samples

Soil samples were taken with a five foot manually operated soil

auger. Physical descriptions were made and samples collected in the

field for further study.


Depth-Recorder Traverses

Bathymetric traverses were made with a sonar depth recorder using

a 400 cps, transducer-generated sound source. The acoustic readings

agree well with sounding line measurements in areas where the bottom

is solid but the latter are as much as two feet deeper in the more

aqueous sediments.

Laboratory Methods


Physical Description of Cores

Core samples were described with the aid of a hand lens and a

binocular microscope using reflected light. Colors were described

according to the standard Rock Color Chart (distributed by the

Geological Society of America). Grain sizes were estimated with the

help of a sand-size comparator, and at certain sand horizons sieve

analyses were made.

Water Content, Loss on Ignition

Both grab samples and core samples were analyzed for water con-

tent (weight loss at 1050C) and organic matter (weight loss on ignition

at 5500C). The water contents were recorded but not used in the case









of the grab samples because of uncertainty as to the effect of

mixing which could have occurred during sampling.

Sand Content

At the time that samples were taken for water content and organic

matter, a representative quarter was taken to determine sand content.

Both samples were immediately weighed. The sample for sand content

was boiled in a 5 percent KOH solution for 10 minutes to disaggregate

the sediment. The sample was washed over a 62 micron sieve (#230 U.S.

standard sieve mesh) until the sand was clean. The sand was dried and

weighed. Assuming the dry weight percent and loss on ignition at 550C

to be constant in the two samples, the sand was then computed both as

a percent of the dry sample and as a percent of the ash content.


Sieve Samples

Sand samples from cores and grab samples which were selected for

sieve analysis were washed to remove the fractions less than 62 microns,

dried, and sieved with a Ro-Tap for 15 minutes. The less than 62

micron fraction was negligible (less than 3-4%) and was plotted as a

"less than 62 micron class"; a procedure which did not affect the

final calculations as none of the values needed for computations.of

size parameters fell in this range. Values for median diameter, graphic

mean,inclusive graphic standard deviation, inclusive graphic skewness,

and graphic kurtosis were computed according to Folk (1974).

Silt Fraction

Samples were taken at 40 cm depth intervals in core 012376 1300;

each consisted of 3 to 5 cm of core. The samples were first treated






















SAMPLE Md Mz (j SkI KG

102874 1600 1.6 1.6 0.65 -0.02 1.12

0927751625 62-68cm. 1.4 1.4 0.73 0,07 1.08

0927751625 78-84 cm. 1.1 1.1 0.65 -0.03 0.79

0927751625 92-98 cm. 1.4 1.4 0.74 0.05 1.02

1001 75 1522 2.0 1.9 0.68 -0.16 0.90

102375 1600 2.0 2.1 0.61 0.04 0.92

012376 1600 300-305 1.9 1.9 0.70 .0.05 1.06
cm.
012.376 1600 320-325 2.4 2.4 0.69 0.72 1.01
cm.


Table 1. Sieve analyses for selected sand samples from
Newnans Lake.









with sodium hypochlorite (clorox) to remove the organic material and

then centrifuged to separate the clay and silt.

Due to the difficulty in separating the organic and clay components,

and due to the small amount of material obtained from each sample,

no accurate weight percent could be determined. It was decided instead

to determine whether there were any significant variations between

samples in the types of sediment making up the silt fraction. Therefore,

small amounts of each sample were mounted on microscope slides with

Permount.

The samples were viewed with a petrographic microscope under

transmitted light. Samples were point counted to determine the signi-

ficant percentages of different types of grains.

There are four major components of the silt fraction: diatoms,

sponge spicules, detrital quartz, and reworked amorphous silica

grains.


Diatoms and Sponge Spicules

While counting grains of silt size, the most abundant diatoms

were catalogued into genera. In samples in which only a few diatoms

were present (against a larger percentage of detrital silt), a second

count was made to increase the reliability of the statistics. Several

published keys were used in the identification of the diatoms.

No attempt was made to classify sponge spicules as to genera or

species. They were, however, catalogued into general classes of smooth

acerate, spined acerate, spherical and birotulate.









Detrital Silt

The detrital quartz grains of silt size generally are angular

with abundant vacuoles and often show undulose extinction under

cross-nicols.


Reworked Amorphous Silica

The reworked amorphous silica grains were commonly pitted or

frosted and tend to be rounded. Many of the grains appeared to be

reworked sponge spicules, but positive identification was not possible.

Pollen counts

Sediment samples for pollen analyses were taken from four of the

cores at 10 to 20 centimeter depth intervals. The pollen were

extracted from the sediment by standard acetolysis/hydrofluoric

acid techniques (Kummel and Raup, 1965), stained with saffranin, and

mounted in glycerin. The pollen sum was composed of a minimum of

200 grains from trees and woody plants (AP). The herbs (NAP) and

other grains (spores, etc.) which were significant enough to count

were computed as a percent of the pollen sum.

Identifications were made with the aid of a small personal

reference collection, the reference collection at the University of

Florida (Florida State Museum), and from published keys (Kapp, 1969;

Erdtman, 1943). Identifications of pollen were carried to the generic

level only. The use of the suffix "type" after the genus.name

indicates that the grains may belong to the named genus or to other

genera of similar or identical morphology.

Percentages of pollen genera for the four cores or illustrated

as pollen diagram in figures 10, 11, 13, and 14.









Charcoal Fragments

Charcoal fragments were also counted in the slides from core

012376 1300 prepared for pollen analysis. Only particles greater than

about 4 microns were counted; smaller fragments, possibly also charcoal,

were extremely plentiful but were difficult to distinguish from pyrite

and heavy minerals which appear similar under transmitted light. In

the case of the higher percentages, only several hundred grains were

counted rather than the total number, and the total number of charcoal

fragments were plotted as a proportional part of the total AP.













PRESENT SEDIMENTATION


Lake Sediments


The general trends discerned were: (1) The sand and ash content

increases toward the shore line where wave action creates a higher

energy environment, and (2) organic matter (loss on ignition at 5500C)

increases away from the shore to where quieter conditions exist.

There is a notable difference however between the north and

south parts of the lake: In the north the sand content drops off

rapidly outward from the shore line indicating a sharp transition from

high to low energy conditions; whereas, in the south end there is a

more gradational change of sediment type away from the shore.

The gross compositions are plotted on a ternary diagram in which

the three end members are sand, silt-clay and organic (see figure 7).

A tendency toward a linear relationships is evident, with compositions

trending across the center o,f the graph from the sand apex to the

center of its opposite side of the triangle. This trend indicates that

there is a more or less constant relationship between the silt-clay

and the organic material, their percentages relative to each other

remaining fixed as the sand percentage varies.

The constant relationship between silt-clay and organic matter

is explained by the nature of the silt fraction. The silt, at least

in the center of the lake, is almost entirely diatoms and sponge

spicules, both of which are produced biogenically in the lake. The


13
















































































20



4, .A P 'I s

SILLAMPLE LOCATION
NEWNANs LAE -20- CONTOUR REPRESENrTNG SAND AS A PERCENT
2 1 05 0 t -ILE

COUNY T SCALE
CONTOUR INTERVAL 20 PERCENT
MAP DAtA E-R USG 'O POGRAPHIC MAPS I' MS'NUlIF QOJAQPAN' T

Areal distribution of sand percentages in surficial Newnans
Lake sediments.


Figure 2.
























































Figure 3. Areal distribution of ash percentages in surficial Newnans
Lake sediments.




















































































































.L.. : AMP OR MARS
S x n ...... - FATOMETER TRAVERSES
SUPPLEMENTARY SOUNDINGS
OEPTM CONTOUR. DATUM I5 66 FEEt Ml
o 0 I LF




MAP A RM uIS rT APAIC MPS ( -MINUTE OUARA T S
1____O + ____1 iO^K


SCAL
CO TU 1T"*LFE


Figure 4. Depth contour map of Newnans Lake.











012376 1300


0-240 cm Gyttja, dusky brown (5YR 2/2).
Aqueous at the surface, becoming firmer with depth.
240-500 cm Gyttja, brownish black (5YR 2/1).
Firmer and more gelatinous than the above unit;
contact is gradational. Numerous sand laminae,
especially prevalent at around 250 cm and 400 cm.
A large sand filled, boring was noted at 402 cm.
500-600 cm Gyttja, clayey and silty, greyish
black (N2). Firmer and more cohesive than the
above unit; contact is gradational.
600-609 cm Clay, medium grey and dark grey
(N5, N3) mottled. Gradational with the above unit.


Lithologic descriptions of cores from Newnans Lake.


i >-
z <
< -.
Ln U


0






100






200


300






400


500






600


Figure 5.










012376 1600


0-140 cm Gyttja, brownish black (5YR 2/1).
140-295 cm Gyttja, brownish black (5YR 2/1),
more gelatinous and firmer than the above.
Numerous small sand lenses and burrows.
295-337 cm Sand, medium light grey (N6)
grading to mottled grey and then grey sand.
Plant debris at 295 cm.
337-371 cm Sandy clay, brownish black
(5YR 2/1) to medium dark grey. (N4) sandy
clay, slightly mottled.


0-74 cm Gyttja,
to sandy gyttja.
74-135 cm Sand,
grained.
135-149 cm Clay
grey (N6).


brownish black (5YR2/1)

very light grey (N8), medium
and sandy clay, medium light


Lithologic descriptions of cores from Newnans Lake
(continued).


0






100






200






300


400 -


092775 1600


0






100






200


Figure 5.












102375 1600

Of

C)


U
z
< >-

O <
0 tn U


0-72 cm Gyttja, brownish black (5YR 2/1)
with some leaves and organic debris.
72-83 Sand, light brownish (5YR 6/1) medium
to fine grained.
83-118 Clay, medium light grey (N6).
118-147 Sand, very light grey (N8), medium
grained.
147-150 cm Slightly clayey sand, light grey
(N7).
250-280 cm Sand, light grey (N7) with dark
horizons of organic rich sand at 250 and 260 cm.
280-330 cm Clay to sandy clay, medium light
grey (N6).


092775 1625


x 0-57 cm Gyttja, brownish black (5YR 2/1)
with sand laminae becoming more abundant toward
the bottom. Large boring filled with sand at
S55 cm.
57-70 cm Sand; very light grey (N8), medium
grained.
70-73 cm Gyttja brownish black (5YR 2/1)
S with sand laminae.
73-105 cm Sand, very light grey (N8) to
medium light grey (N6), medium grained.
105-142 cm Sandy clay to clay, medium light
grey (N6).



Lithologic descriptions of cores from Newnans Lake
(continued).


0






100


200






300


0






100


Figure 5.











072875 1440


U

W< <
-0 >- U




50-LI


0-30 cm
in part.
30-55 cm


Clay, medium light grey (N6), sandy

Clay, pale green (5G 7/2).


072875 1600


100 [


0-65 cm Gyttja and sandy gyttja, brownish black
(5YR 2/1).
65-90 cm Sand, very light grey (N8), medium
grained.
90-105 cm Clay, medium light grey (N6).


102475 1400


100





200


Figure 5.


Core compressed from about 390 cm to 240 cm.
0-178 cm Gyttja, brownish black (5YR 2/1),
aqueous at surface, becoming firmer with depth.
Sand laminae noticable between 90 and 150 cm.
178-238 cm Silty, clayey gyttja, greyish
black (N2).
238-240 cm Clay, greyish black (N2).


Lithologic descriptions of cores from Newnans Lake
(continued).























0-25 cm Peat, dark yellowish brown (10YR 4/2)
25-85 cm Sandy peat grading to organic rich
sand, brownish grey (SYR 4/1). Root at 45 cm.
85-120 cm Sandy clay, medium light grey (N6)
interbedded with sand and silt lenses. Several
zones with pebble sized rubble. Some foraminifera
in the silty zones. One shark tooth found at
110 cm.


072875 1839


072875 1300


100 .


Figure 5.


Lithologic descriptions
(continued).


0-30 cm Fibrous gyttja, brownish black
(5YR 2/1).
30-60 cm Peat, brownish grey (SYR 4/1).
60-100 cm Sand, very light grey (N8), medium
grained.
100-120 cm Clay, light grey (N7) and light
olive (104 5/4) marbled.












0-23 cm Sand, brownish grey (SYR 4/1),
organic rich.
23-98 cm Sand, light grey (N7), medium grained.
98-115 cm. Sandy clay, medium grey (N5).


of cores from Newnans Lake


072175 1930


o >-
Z 4
U -J
t> .U


0





100
tCM3












100275 1515
i)
rr
m
CJ


o >-
z <
-- -
i- U







'.'.'


'.;..


0-45 cm Sand, dark grey, organic
rich, medium grained.
45-75 cm Sand light grey to white, medium
grained, slightly cohesive.
75-150 cm Slightly clayey sand, light grey,
medium grained.


100275 1600


0-90 cm Sand, brownish grey, organic rich,
medium grained.
90-120 cm Sand, grey to yellow, medium grained.
120-140 cm Slightly clayey sand, grey to
yellow, medium grained.
140-150 cm Clay to clayey sand, grey.


100275 1630


0-30 cm
grained.
30-144 cm


Sand, dark brown organic rich, medium

Sand, yellow, medium grained.


Lithologic descriptions of soil samples in the vicinity
of Newnans Lake.


0






100


0






100


0






100


Figure 6.











100275


0






100


1345





u

z
0 v

(D,
0 u
/^.T'


100275 1450


0






100


0-45 cm Sand, grey, fine to medium grained,
abundant organic debris.
15-115 cm Sand, yellow-brown, medium grained.
115-125 cm Sand, light yellow, medium grained
with dark yellow brown clayey sand.
125-143 cm Clayey sand, light grey inter-
layered with brown clayey sand.













0-60 cm Sand, dark to light brown, medium
grained, abundant organic debris.
60-140 cm Sand, light yellow brown, medium
grained. Contains a few 1 cm thick layers
of dark red brown clayey sand at about 135 cm.


100275 1500


[0r L ,
SI '.




100


0-55 cm
grained.
55-60 cm


Sand, black organic rich, medium

Sand, light grey, medium grained.


Lithologic descriptions of soil samples in the vicinity
of Newnans Lake (continued).


Figure 6.

















Composition of Newnans Lake sediments as represented
in ternary diagrams. Figure 7A is a plot of values
of recent lake samples. The numbers 1 through 45
relate to the sample numbers as follows:


1836
1853
1920
1025
1535
1545
1610
1745
1810
1820
1045
1100
1115
1120
1130


020275
020275
020275
020275
020275
020275
020275
020275
020275
020275
020275
020275
020275
020275
020275


1140
1145
1155
1200
1210
1215
1220
1230
1240
1245
1255
1300
1345
1400
1415


020275
101775
102375
012376
012376
090476
090476
090476
090476
090476
090476
090476
090476
090476
090476


1550
1428
1600
1300
1600
0830
0850
0900
0920
0935
1000
0945
1035
1045
1125


Figure 7B is a plot of values from core 012376
refers to the depth in centimeters.


1300. The number


Figure 7.


1 -
2-
3-
4-
5-
6-
7-
8-
9-
10 -
11 -
12 -
13 -
14 -
15 -


080274
080274
080274
020175
020175
020175
020175
020175
020175
020175
020275
020275
020275
020275
020275















'.9,30


SEDIMENT RELATIONSHIPS
FOR GRAB SAMPLES


012

18 *026


1, 0 36 44
2 "U 3


SILT-CLAY


OHGA NIC


SILT-CLAY
















I S S S S *I -








*/.Sand (1.7)(57-'. Organic matter)

Correlation coefficient (r) = -0.98
r' 0.96


00


0 \0
\,5 0@


0 10 20 30 40 50 60


ORGANIC CONTENT as a percent of the dry weight

Arithmetic plot of sand content and organic content
(loss on ignition) for surficial sediments from
Newnans Lake.


100'




90



80-


I I


It".


S\


Figure 8.


i |


-1









sand on the other hand, is composed of detrital quartz, introduced

and sorted inorganically.

A binary plot was made of percent sand against percent organic

matter (figure 8). This plot shows more clearly the straight line

relation noted in the ternary diagram. The slope is markedly negative

showing a decrease in organic with an increase in sand.. By calculating

a linear regression of the points on the graph the relationship is

quantified as:


% Sand = (1.7) (57 % organic matter); r = -0.98


Soil Samples


The general trend of the soil samples indicates that there is

for the most part four to five feet of sand overlying the silicate

clays and clayey sands of the Hawthorne sediments. The scarcity of

natural exposures of clay minerals indicates a deficiency of these

materials available for transport into the lake either by runoff or

stream transport. The deficiency of clay in the surficial drainage

area results in a deficiency of clay in the presently accumulating

lake sediments.


Summary


Presently the lake is accumulating primarily detritial quartz

sand, biogenically derived silt grains, and organic matter. The

quartz sand content decreases and the biogenically derived sediment

content increases away from the high energy environment of the shore

line.










In the central part of the lake the sediment is almost entirely

organic matter and diatoms. Little silicate clay is presently reaching

the center of the lake probably due to the scarcity of exposed

source areas.














HISTORY OF SEDIMENTATION


The history is based primarily on an analysis of core 012376 1300,

from near the center of the northern part of the lake (figure 1).

This core represents the most complete section cored and its central

location provides the least interference from later disturbance and

reworking.


Pollen Diagram

The'trends in the AP diagram (figure 10) show a gradual decrease

in Quercus (oak) up the section and a sudden increase in Taxodium

(cypress) above about 300 cm. There is not much variation in the

Pinus (pine) curve. In the NAP (herbs) diagram, there is a significant

decrease in all of the NAP at about 400 cm and again above 300 cm.

Comparison of the pollen diagram for Newnans Lake with that

for Mud Lake, 40 miles to the SE, shows the same general trends but

the Newnans Lake diagram lacks the marked change in pine and oak

percentages noted in Mud Lake (Watts, 1969). The diagrams are

certainly similar enough for valid correlation. As indicated by the

rise in the cypress pollen above 300 cm in figure 8, all of Watts

zone M-1 (Pinus-Taxodium) is present, and the NAP curves indicate

that a good part of the M-2 (Quercus) zone is also present. These

similarities and the resulting correlation with the established ages

in Mud Lake, indicate that Newnans Lake developed between 5000 and

8000 years ago.









The fungal spores vary in character throughout the core becoming

more diverse as well as more numerous toward the bottom. The meaning.

of this curve is not clear but it is of interest that it tends to

parallel the NAP curves.

Correlation of the pollen diagrams from other cores in the lake

with core 012376 1300 indicates that the sedimentation of organic

sediments began at significantly later times in the shorter cores.

A comparison of 012376 1600 to 012376 1300 shows that sedimentation

began both at a later time and at a higher elevation at 012376 1600

(in the southern part of the Lake) indicating a general rise in lake

level and lateral spreading over a period of time. Sedimentation

at the two points, once it began, appears to have been at approximately

the same rate. Comparison of the above cores with 092775 1625 and

102375 1600 indicates much the same pollen trends, but data from

these cores is probably less reliable due to their proximity to

shore (figure 1).


Charcoal Fragments

Charcoal fragments calculated as a ratio of the total AP in

core 012376 1300 are plotted in figure 9. In general there is a

rapid decrease in charcoal fragments moving up the core to about 400

cm, an increase to 300 cm, a decrease to 280, with a slight increase

and then general decrease to the surface. Because the number of

charcoal fragments is presented as a statistical parameter which is

dependent on the number of AP grams counted rather than a weight

percent, the ratio should vary with the pollen influx, but considering

















Figure 9. Lithology, water content, loss on ignition, sand content
and charcoal fragments in core 012376 1300.

















0123761300 NEWNANS LAKE
ALACHUA COUNTY, FLORIDA




O WAT







-r-
II
-: 0 5<













GYTTJA











/-
w-

w-


-o-




SGYTTJA
(GELATI.CUS-




fr r-
.Y-A













CLAY
V- --r-

-- --Y-












-_r c- CAY


LOSS ON IGNITION
ER (550 C) SAND CHARCOAL
) 100 0 50 100 0 50 100 10' 10'2 10 10' 10


0




50




100




150




200




250




300




350




400




450




500




550




600


PErCErLT LOGArTMIC SCALE
PERCENT ErCCCNT PERCENT FRAGoMENTSAP


0




50




100




150




200


V,)
c:
250 W




300 U
u
z

I-
350 a




400




450




500




550




600


I I I
.OG, Allll TM M I C SCALE
I [RC[N T leRAGM[NTS / AP


















Figure 10. Arboreal pollen diagram for core 012376 1300.
















0123761300 NE'
ALACHUA COUNTY.


AP NAP


WNANS LAKE
FLORIDA TREE POLLEN







o 1o Q0 43 40 50 6s 70 0 2 0 40 60 0 10 20 5 05 050 0 5 O0 5 05 0 5 0 05 0 5 PECENT


cUJLUJY 4 U tY J


I INCLUDED IN POLLEN SUM


z


150 1


200




Ln

z
U


0 350

a


250 J
LJ

z
300 L
z

I-
350
ui



400



450



-MO


450



500

















Figure 11. Nonarboreal pollen diagram for core 012376 1300.


















0123761300 NEWNANS_ LAKE
ALACHUA COUNTY, FLORIDA HERB POLLEN. FINGAL SPORES AND ALGAE






o 10 200 0 20 340 0 65 70 80 90 ooo 0 o10 oo 5 0 O 5 10 20 30 40 50oo 80 0 50 PERCENT
o












100
150






w"

I
z

z











450



Now





.j ... .,. . . . .

LUDED FROM POLLEN UM NOTE MCANGE IN SCALE 00


0



O50



100



150



200




S,
Wo 250
w
I
t-









400



450



500



550



600

















012376 1600 NEWNANS LAKE
ALACHUA COUNTY, FLORIDA


O
O
I-

_j







GYTTJ












GELA
SGYTT










SAND


CLAY


092775 1625


LOSS ON IGNITION
WATER (5500C) SAND
0 50 100 0 50 100 0 50 100


A


TINOUS
JA


0 50 100 0 50 100


GYT TJA


SAND
GYTTJA
SAND


CLAY


0 50 100 0 50 100 0 50 100


Figure 12.


Lithology, water content, loss on ignition, sand content

and charcoal fragments in cores 012376 1600, 092775 1625,
and 102375 1600.


50


300


150L


PI RECENT
0




50




100




150




200




250


LI

300


Lu
I-


z
350 W
U

I
0 -
a
0


50




100




150


102375 1600


-,0




S50




S100
















Figure 13. Arboreal pollen diagram cor cores 012376 1600,
092775 1625, and 102375 1600.

















012376 1600 NEWNANS LAKE TREE POLLEN
ALACHUA COUNTY. FLORIDA





AP NAP o P:
S 50 100 0 1 20 030 40 5so 70 10 20 30 40 50 60 0 10 20 30 O O5 05 05 05 0 05 0 5O 0 0 50 PERCENT 0 300




50




100






100
100 TREES

0 150 O
1-50


200
200





S- I
250 250



i HERBS 300
i 300 300


LZ 092775 1625 NEWNANS LAKE


0 50 100 0 10 20 30 40 50 60 70 O 10 20 30 40 50 600 10 20 30 0505 050505 0 5 05 0 0 5 OS0 5o o PERCENT 0 300
: _O







100


102375 1600 NEWNANS LAKE


O so50 100 0 10 20 30 40 so50 60 70 0 10 20 30 40 so50 60 O 10 20 30 05 OSO 0 S 0S 5 5 0 5 OSO 5 OS OS PERCENT O 300






100

'00 iNC LUDE , L S ._
| INCLUDED IN POLLEN SUMI



















Figure 14. Nonarboreal pollen diagram for cores 012376 1600,
092275 1625, and 102375 1600.












012376 1600 NEWNANS LAKE
ALACHUA COUNTY FLORIDA


HERB POLLEN FUNGAL SPORES AND ALGAE


0 20 30 4, 50 60 3 o 0 0 80 90 10005 0 10 05 0_5 0_5 05 0 0 20 30 40 500 800 50




100




200
'50 I '1

200

250


30 300

z 092775 1625 NEWNANS LAKE

S 0 0 20 0 !O 20 30 40 50 60 70 80 90 100 0 5 0 10 0 55 0 5 0 5 0 10 20 30 40 50 80 0 50


L r [ -L I : ^

1000

102375 1600 NEWNANS LAKE

0 0 20 0 10 20 30 40 50 60 70 80 90 10005 0 10 0 5 0 5 0 5 0 10 20 30 40 50 0 80 50



EXCLUDE FROM EN SUM NOTE CHANGE IN SCAE


EXCLUDED FROM POLLEN SUM NOTE CHANGE IN SCALE


-11


~,O"t~'
r4P~


id';
aO'F


^< ^ '^ :,,, ,
01 'p.-u









the extremes in values the overall trend should remain the same.

The meaning of the figures is somewhat ambiguous. There are two pos-

sibilities for the reduction in charcoal fragments other than a

significant increase in pollen influx; one is a reduction in the

number of fires around the lake and the other is a decrease in the

amount of runoff into the lake.


Sand


The sand content of core 012376 1300 is presented in figure 9

along with the water content and loss on ignition. Sand is plotted

both as a percent of the total dry weight and as a percent of the

ash content. This second plot is included to facilitate independent

comparison of the sand percentages versus the silt-clay percentages,

both within the inorganic or ash fraction.

The sand percentages produce two significant maxima: one at

about 400 cm, and the other at about 280 cm. The ash content in-

creased at the same two levels. These sand maxima are produced by

two types of concentrations within the core: the first is an increase

sand dispersed within the gyttja, and the second is an increase in

the number of discrete sand laminae, many of which are only a few

grains thick. A few animal borings filled with sand were also

present, but these were excluded from the samples before analysis.

The two increases in sand also occur at the same horizon as

the significant decreases in NAP pollen.


Silt


The silt size particles undergo an abrupt change in composition









at a depth of 400 cm in core 012376 1300 (figure.15). Below that

depth the silt grains are composed predominantly of detrital quartz,

but above 400 cm they are almost entirely diatoms and sponge spicules.

This change could indicate any of three conditions: (1) greatly

increased organic productivity within the lake, (2) interruption of

the previous source of detrital quartz, or (3) possibly both effects

operating simultaneously. The detrital quartz was probably from

weathering of the Hawthorne Formation sediments surrounding the.

lake.

The percentage of reworked amorphous silica grains also de-

creased above 400 cm. These grains probably also had their origin

in the Hawthorne.

It is of interest to note that although the silt sized detrital

quartz decreased significantly above 400 cm, thus paralleling the

first large increase in sand size quartz, there is no corresponding

increase in detrital silt at 280 cm where the sand shows a second

major increase.


Diatoms


Diatoms in core 012376 1300 consist primarily of two genera.

Campylodiscus dominates from 560 upward to 520 cm, with Melosira

dominating the remaining upper part of the core. The only other

genus of significance is Anomoeoneis which appears at 520 cm as 22

percent of the total and rapidly decreases upward, disappearing before

320 cm. Numerous other genera appeared but were quantitatively in-

significant. The small percentages of these accessory genera and the

uncertain identifications of certain grains, suggested that the









diatoms would best be presented as a planktonic versus benthonic

curve, the Melosira making up most of the planktonic fraction.

The plot of planktonic versus benthonic diatoms (figure 15)

shows the sudden dominance of planktonic forms above 500 cm. The

curve shows two significant deviations above this, one at 380 to 440

cm where there are no diatoms present and the other at 280 cm where

the proportion of planktonic forms decreases by 20 percent. These

two deviations are notable in that they occur at the same depths as

the two increases in sand percentages and the two significant decreases

in NAP.

The diatom frustules in the interval from 260 to 320 cm were in

relatively poor physical condition, possibly indicating reworking by

more active energy conditions. Samples between 380 and 440 cm were

virtually free of diatoms. No genus other than Campylodiscus was

found at 560 cm. Samples below 560 cm were free of diatoms although

sponge spicule fragments were abundant.

This interval from 380 to 440 cm which is lacking in diatoms

presents a problem in interpreting the continuous sedimentary history

of the lake. Although there is no significant lithologic change in

this part of the core to indicate a lapse in sedimentation, the absence

of diatoms could represent a period of reworking. If so, then an

erosional vacuity of undetermined length may exist in the history

recorded by the core.

Sponge Spicules


Sponge spicules when plotted against the total diatom sum, show

two dominant peaks, one at the bottom of the core and the other at









about 400 cm. Below 560 cm no diatoms were found, but broken sponge

spicules were common.

It is interesting to note that the increase in sponge spicules

at 400 cm coincides with the lower sand increase. This implies an

event of ecological significance at that time, the nature of which is

unknown.


Gross Variations in Sediment Types


A ternary plot of gross variations in sediment types shows that

the samples from the upper part of core 012376 1300 have interrelation-

ships similar to those previously discussed for the surface grab

samples (figure 7). However, below 500 cm there is a marked trend of

values toward the silt-clay end member. From the lithology of the

core and the silt sized analysis (figure 13) this would be construed

as a higher percentage of silicate clay minerals and detrital quartz

silt, both probably derived from weathering of exposed Hawthorne

sediments around the lake.


Cross Section


The cross section (figure 16) was constructed with the help of

various cores, probes, soil samples, and well logs. The surface of

the organic sediments as used in the cross section, was taken from

soundings produced by lowered weights or pipes made at the time of

sampling. These soundings indicate the top of the "solid" sediments

as opposed to the more shallow, "false bottom" picked up by the

acoustic fathometer. This difference is as much as two feet.


















Figure 15. Distribution of silt grains and diatoms in core
012376 1300:

A. Silt grain types
B. Planktonic versus benthonic diatoms


















0123-613C0 NEWNANS LAKE
ALAC-UA COUNT'. FLORIDA


SILT DIATOMS
u50 100 00 0 50
3 50 1001. 0 1300 0 50 '00"'.





,,--r---~-- rc ~-r1


DIATOMS















: S:tCULES




'DETRITAL QUARTZ



DIATOMS -


d
i
o

6
I
O

x
r


e

9


-NO O lATOMS









PREDOMINANTLY BENTHONIC DWATOMS -



NO DIATOMS


.c.


cu
C *CCC

0



50












I- 20



25C



; 30C u



350
: 0
I













*-;c-





**'


'50



200



250


z
300
Z

_ 350









The gyttja blankets all other sediments in the lake with a few

exceptions such as near shore and immediately off of the three points

of land. In the deeper parts of the lake the gyttja takes on two

forms, one an aqueous muck which grades downward into the second stage,

a firm gel-like gyttja. The gyttja is generally underlain by a fairly

clean sand throughout the southern part of the lake and near shore in

the northern part. However, the central and northernmost part of the

lake, clayey-silty gyttja underlies the gyttja, and no clean sand layer

was found. Grey clay and sandy clay underlie both the sand and the

clayey-silty gyttja.

All of the contacts except the sand to gyttja contacts are

gradational, suggesting a gradual change in conditions or possibly

some active bioturbation. The sand to gyttja contact indicates an

abrupt environmental change.

The grey clay which underlies much if not all of the lake basin

is probably derived from reworking of nearby Miocene sediments.

Mineralogically a sample of the grey clay from 072875 1440 at a depth

of 29 to 31 cm is entirely montmorillonite.

The sand is probably the result of winnowing by wave action and

indicates old shore line deposits which were created at lower lake

levels. Samples taken for sieve analysis show sorting parameters

indicative of a fairly high energy environment (table 1).

Core 072175 1930 is of interest in that the sandy clay at the

base contains pebbles, rubble, and a single sharks tooth which

appears to have been reworked directly from the adjacent hill. The

road cut through the edge of the hill yields similar pebble sized debris.















NEWNANS LAKE
o ALACHUA COUNTY FLORIDA
a:
Lw


110 110


or S---- N 100
30 4 NORTH-SOUTH CROSS SECTION A' 30




. 0 80
U 8 8




u 202 0
50C SE MNTS 25



0.50 0- .50
SAID z -



> .0 UA W TC S aSC
Lu









To .,TICAl E-GEuR, 200 1 10-
90 90' o s"






70 70
o0 L 200


0 -T ---sr T C- _. 30








-" o -,o oo F E 1
S5 ES O- a
25 25
30 a 2 o90 C 00

7 a 0 <





S50-15 / 50
zEAST-WEST CROSS SECTION 90



Lu 30 T^ 2 S
S70 70 <


SNor GAIC SEMT d es- st c ss s i s of N s L




North-south and east-west cross sections of Newnans Lake.


Figure 16.










In core 092275 1625 a small lens of gyttja is isolated in the

sand. Both contacts are sharp. This could indicate a segment of

sediment which was isolated and buried during a storm.

Ten well logs for the area around the lake show that the lime-

stone surface in the area is from 30 to 50 feet above mean sea level.

Two notable exceptions are from the bridges at Hatchet Creek and

Prairie Creek. Limestone was encountered at 10 feet above MSL at

Hatchet Creek and at about 3 feet above MSL at Prairie Creek. Since

this information is from drillers logs no indications can be given

as to the age of the rock units involved (Hawthorne or Ocala). The

notable feature, however, is that the rock surface is not far below

the lake bottom, usually within 10 to 15 feet.













CONCLUSIONS


If Figures 7, 8, and 9 are compared, several interrelationships

are apparent within core 012376 1300. The lowest part of the section

from the grey clay at 600 cm to about 500 cm, is a clayey, silty gyttja

characterized by a high percentage of detrital quartz silt grains, a

dominantly benthonic diatom assemblage, and a higher percentage of herb

and weed pollen (NAP).

Above 500 cm, in the gel-like gyttja, the sand content of the

sediment increases, producing a peak at about 400 cm. This increase

in sand is accompanied by a decrease in NAP, a lack of diatoms, and

an increase in detrital quartz grains. The increase in sand and lack

of diatoms suggests a higher energy environment, capable of sorting

the sand and destroying the diatoms by wave action. The increase in

detrital quartz, as well as the sand, is probably derived from

increased sediment transport into the lake as well as reworking of

older lake sediments. The lack of diatoms may indicate that the re-

working has developed an erosional vacuity.

Above 400 cm the sand content again decreases, with an increase

in NAP and the reappearance of.diatoms, which rapidly become the

dominant silt grain type. The lake at this time could be considered

eutrophic, as the planktonic types make up better than 90% of the

total diatoms.

After the above decrease, the sand gradually increases again to

about 280 cm, with a decrease in NAP and a decrease in planktonic









diatoms. The increase in sand indicates a higher energy environment,

and the increase in benthonic diatoms suggests a lowering of lake

level. There is no accompanying increase in detrital quartz silt

grains diatomss remain the dominant silt type). The sparcity of

detrital quartz silt grains could be interpreted as a decrease in

sediment transport into the lake, such as produced by development of

fringing cypress swamps. Thus, the only source of sand would be the

reworking of older sediments.

Above 280 cm the sand decreases again with an increase in planktonic

diatoms. At this horizon there is no accompanying increase in NAP,

but there is a significant rise in cypress pollen. The meaning of

this change is not clear, but it is probably related to the rise in

the water table and accompanying rise in lake level, which could produce

the conditions for extreme cypress swamp development.

Core 012376 1600 also shows two major sand influxes. Exact

correlation between the two cores is difficult, but the base of the

012376 1600 core is about the base of Watts (1969) M1 zone or about

the 300 to 350 cm level in core 012376 1300. The lower sand peak

012376 1600 may correlate with the upper peak in 012376 1300, but

the upper peak in 012376 1600 apparently has no corresponding peak in

012376 1300. This lack of correlation can be explained by the nearer

shore, higher energy location of 012376 1600, and the lower energy

at core 012376 1300, further out in the lake. In fact, the present

areal distribution of surficial sediments demonstrates that the sand

percentages decrease rapidly from the shore line; presumably the same

relationship was true in earlier times of lake development. In light









of this, correlation of sand peaks would be possible only between very

closely spaced cores and probably not between cores as widely spaced

as these two. The same difficulty of correlation holds true for the

sand maxima in core 102375 1625.

Another possible explanation of these sand increases could be

that storms disturbed a local section of sediment, thus creating a

purely local, uncorrelatable phenomenon. However, it is difficult to

see how a storm would effect one area of the lake rather than dis-

turbing all of the sediments in water shallow enough to be agitated

by the waves, and even more difficult to understand how a storm would

affect up to a full meter of sediment. Yet this possibility cannot

be dismissed without further research.

The overall upward trend in the charcoal curve of core 012376

1300 is toward fewer charcoal fragments. This could be explained by

a gradual lessening of forest fire activity around the lake, possibly

related to a trend to a wetter climate.

The fluctuations in the charcoal curve are difficult to inter-

pret: It would be expected that greater concentrations of charcoal

would be brought on by the forest fires accompanying droughts, yet

the charcoal concentration decreases at the times of greatest sand

influx which could also be interpreted as drought periods. There are

at least two explanations for this coincidence. The first is that the

charcoal is related to sediment transport into the lake and that total

transport decreased during these times of lesser concentrations,

making the increase in sand largely dependent on reworking of older

sediments. A second point is that since the number of charcoal fragments

is plotted as a percent of the total AP, this may well represent little









more than a statistical trap. Reworking of the sediment could

concentrate the pollen from older sediments, or a greater influx

of pollen from outside the lake could make the charcoal appear to

decrease. An important consideration is that of reworking. Reworking,

especially in a sandy environment, could break down the charcoal

fragments, creating a lowered concentration.

In summary the charcoal influx into the lake is probably a function

of fire activity, sediment transport, and reworking. The decreases in

concentration at 400 cm and 280 cm may represent times of reworking,

although more work is necessary to draw any valid conclusions.

If the areal distribution of present day sediments (figures 2

and 3) is used to interpret the past, the general trend to note is

that the sand increases toward the shore and the organic content

increases away from shore. The sandy sediments represent a shallow

or nearshore environment. The boundary between the sandy vs. organic

sediments shifts with a climatic fluctuation toward either wetter or

drier times, but the general pattern of sediment types should remain

the same. Thus, during drier times, increased wind transport of sand,

coupled with increased chance of bottom exposure would extend the sandy

areas, probably producing the sandy horizons in the central lake cores.

This concept of lowered water level is supported somewhat by ideas

presented by Schumm (1965) on rainfall and sediment transport. The

idea relevant to this study is that in areas of relatively high

rainfall as sediment transport decreased rainfall increases. This

inverse relationship is due to the decreased erodability of the soil


greater than 12 inches per year at a mean annual temperature of
50Fahrenheit.









as the density of ground cover plants increases. At least in the lower

part of the Newnans Lake section, the NAP (grasses, herbs, and weeds)

decreases with an increase in sand; conversely, sand increases when

the grasses and herbs decrease. If the NAP percentage is plotted

against the percentage of sand, a fairly good inverse relationship

develops (figure 17). Above about 250 cm the relationship shifts

indicating a change in conditions. This depth is the point at which

the NAP becomes more or less negligible and the cypress pollen increases.

In summary then, the horizons of high sand percentages may

represent times of increased sediment transport due to reduced rain-

fall, and the reduced rainfall also implies lowered lake level.

Approximate dates can be inferred for the periods of greater

sand influx and presumed aridity by correlation with Watt's pollen

diagram for Mud Lake (1969). The lower sand maxima in core 012376

1300 is located below the top of Watts M2 zone, or somewhat over

5000 years B.P. The second sand maxima is above the base of the M1

zone and therefore younger than 5000 years. The younger of these sand

maxima seems to fit tentatively into the range of 3000 to 4000 years

B.P. which has been described as a period of severe droughts in south

Florida (Gleason et al., 1974).

A general summary of the lake history would begin with a basin

receiving sediments eroded from the surrounding Hawthorne Formation

deposits. At some point in time between 5000 and 8000 years ago the

lake basin began to fill with water as a result of increased rainfall,

rising water table, or probably both. For a while it was a shallow

body of water, perhaps a grassy marsh. The water level rose























*280


*400


CORE 012376 1300


9260


e440


0420


0300


*200


*180


240


S320


9380


*220


25 140
*100120
*80 160
80*0
60.40


.460
*340


5000


360. @540
.520
*560


NAP as a


Figure 17.


percent of the total pollen


Graph showing relationship between NAP and sand content
in core 012376 1300. Solid dots are samples below 250
cm, asterisks are samples above 250 cm.


I II


I









relatively rapidly, producing an open water flora and eutrophi.c

condition with little transition period. This eutrophic condition

has existed for most of the history of the lake sediments.

Twice in the history of the lake there may have been times of

lowered water levels, once prior to 5000 years ago and once about

3000 to 4000 years ago. The last part of the lake history (about

4000 years to present) involved the development of the fringing cypress

swamp, probably as a result of rising water table. During this latter

period there has been little detectable change in natural conditions.

































APPENDIX










Table 2.--Pollen grain counts


092775 1625

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


Total AP

Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar


0 cm. 10 cm.
# % #


117

26

61

3

1

4

4

9

4

2

1



1
--

2


235

3

4

1

3


50 138

11 53

26 36

1.3 1

.4 --

1.7 3

1.7 4

3.8 7

1.7 2

.8 2

.4



.4



1


20 cm.


/00/% # %


30 cm.


4

18

28

-


56

21

15

.4



1.2

1.6

2.8

.8

.8














2.0

1.6

.8

1.2


109

44

68





1

6

7

3

1







1

1


241

3

3



5


5 146

45

31





.4

.5 3

.9 5

.2 5

.4 --

2





.4


2

2

1


61

19

13







1.2

2.1

2.1



.8












2.5

1.6

.4

.8



.4

.4
.4


1.2

1.2



2.1









Table 2. (continued)


092775 1625

Nymphaea

Other NAP

Total NAP

Botryococcus

Pediastrum

Fungal spores


0 cm. 10 cm. 20 cm.
# % # % #


.3.8

22


3 1.3


% AP

% NAP


092775 1625

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix


40 cm.
# %

164 64

35 14

36 14

1 .4

1 .4


.4

2.3

2.3

2.3


1 .4


2.8 27

4.0 74


5 2.0



94

6


50 cm.
# %

115 48

62 26

45 19

1 .4

1 .4

3 1.3

5 2.1

4 1.7

2 .8


1 .4 2 .7


6 2.5



95

5


30 cm.
% # %


7 2.9

i2 22

4 1.6



94

6


70 cm.
# %

116 54

69 32

5 2.3

1 .5


60 cm.
#

164 5

64 2

31 1

4

2

3

10

2

1


%

8

2

1

1.4

.7

1.1


1.4

1.9

4.7

.5

1.4

.5


3.5 10

.7 1

.4 3

-- l1


1 .4


Acer










Table 2. (continued)


092775 1625

Ericaceae

Other AP


Total AP


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nymphaea

Other NAP


Total NAP


Botryococcus

Pediastrum

Fungal spores


285


2.8

8.5

1.0

3.3









.5


2.1

2.5

.4

2.1





.4


6.7

11

1.8


% AP

% NAP


cm.
o/


50 cm.
#


cm.

--
--


60 cm.
#



1


1.2 5

2.3 6

.4 1

1.6 5





-- 1

.4


21

25

2.7


132

228

8


82

70

2.3


--


_----


.


.









Table 2. (continued)


Core
102375 1600

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


Total AP


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae


0 cm.
# %

119 49

39 16

52 22


10 cm.


#

115

55

53

4

3

2

4

10

3

3


%

46

22

21

1.6

1.2

.8

1.6

4.0

1.2

1.2


20 cm.
# %

116 46

50 20

53 21

6 2.4


3.6

4.0

1.2

.8

1.2


30 cm.


%

9 53

4 24

6 16

1 .4

2 .9



5 2.2

4 1.8



1 .4


1 .4


223


7 2.9 8 3.2 6

4 1.7 6 2.4 6

S 2 .8 2

4 1.7 2 .8 2

-- -- -- -- 1


2.4

2.4

.8

.8

.4


2.2

3.1



1.3
1.3


2 .8


S 1 .4 2 .8


Nuphar


---









Table 2. (continued)


Core
102375 1600

Nymphaea

Other NAP


Total NAP


Botryococcus

Pediastrum

Fungal spores


AP % Total

NAP % Total


102376 1600

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer


40 cm.
#

107 4

63 2

32 1

2

4

2

6

11

4

3



1

2


%

5

7

4

.8

1.6

.8

2.5

4.6

1.6

1.3



.4

.8


50 cm.
#

117 5

66 3

14

1

1

4

9

3

5

1


%

3

0

6.3

.4

.4

1.6

4.1

1.2

2.3

.4


60 cm.
#

150 6

64 2

10

2

4

5

3

7

1

1


%

0

6

4.0

.8

1.6

2.0

1.2

2.8

.4

.4


-- -- 1 .4


0 cm.


10 cm.


20 cm.


30 cm.


# % # # I %


3.3

34

5.8


14

123

13


5.6

49

5.2


4.0

46

4.0


4.9

32

6.3


cm.
%

68

21

3.6

.4



.8

2.7

1.6

.4

.8









Table 2. (continued)


102376 1600

Ericaceae

Other AP


Total AP


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nymphaea

Other NAP


Total NAP


Botryococcus

Pediastrum

Fungal spores


% AP

% NAP



012376 1300

Pinus


I .t --

-- -- 1

-- -- 1

-- -- 2


13

28

7.2


0 cm.
# %

197 54


25 cm.

154 5
154 5


40 cm.
#


%
/0


50 cm.


60 cm.


248


cm.
%.


220


1.6

4.1

.8

2.7


1.6 7

6.9 6

-- 1

.4 4


-- 3

.4 1


3.2

2.7

.4

1.6





1.2


29

32

6.8


38

53

6.7


21

25

5.6


40 cm.

200 6
200 6


62

141
141


-----


----


# % # %










Table 2. (continued)


012376 1300

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Ny ssa

Ilex

Salix

Acer

Ericaceae

Other AP


Total AP


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar


369


3.8 1

.8 5

1.6 1

1.4 4





.6


0 cm.


25 cm.


40 cm.


62 cm.


# % # % # %


16

14

1.1

.8

2.2

4.3

3.3

2.4

1.1





.3

.3


4 49

_2 56

.4 --

.7 2

1.1 3

1.8 4

1.1 9

-- 5

2.2 6





.7



2


15

17



.6

.9

1.2

2.7

1.5

1.8


15

22

.8

1.2

.4

3.1

1.2

1.2

.4


336


2.7

3.5



.8


3.9 7

.6 9

.6 --

1.2 2





.6










Table 2. (continued)


012376 1300


- 1 .3


Nymphaea

Other NAP


Total NAP


Botryococcus

Pediastrum

Fungal spores


% AP

% NAP


80 cm.
#

198

47

69

2

2

3

6

10

6

3


012376 1300

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carva

Liquidambar

Myrica

Nvssa

Ilex

Salix

Acer


%

57

14

20

.6

.6

.9

1.7

2.9

1.7

.9


100 cm.
#

125 4

44 1

61 2

4

2

6

10

4



2


1.20 cm.
% #

3 176 4

7 62 1

4 96 2

1.6 2

.8 1

2.3 3

3.9 12.

1.6 6

-- 4

.8 --

m-- 2


0 cm.


25 cm.


40 cm.


62 cm.


# % # # % # %


15

1.4

.5


1.4

4.3

1.1


13

2.4

1.2


5.8

9.3

1.6


cm.
%

49

21

18


.5

.3 3

.8 7

3.3 5

1.6 6

1.1 5

-- 6


1.0

2.4

1.7

2.1

1.7

2.1


a

II

1

'1









Table 2. (continued)


012376 1300


Ericaceae

Other AP


Total AP


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nymphaea

Other Nap


Total NAP


Botrvococcus

Pediastrum

Fungal spores


258


6 1.6


1 .3 -- -- 4 1.1

4 1.1 -- --


11

6.9

2.0


3.9

9.3

2.3


10

5.2

2.5


% AP

% NAP


012376 1300

Pinus

Quercus


160 cm.
# %

183 54

95 28


180 cm.
#

116

26


200 cm.
#

172

48


80 cm.


100 cm.


120 cm.


140 cm.


# % # % # % # %


9 3.1


3.1

14

2.1


220 cm.
#

152 5

52 2


---


---


----









Table 2. (continued)


012376 1300

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


Total AP


160 cm.


180 cm.


200 cm.


220 cm.


_ __ __%# # %


7 71

.3 2

2.1 1

2.3 2

2.1 3

1.5 3

.3 3

.9 3

.3

.3



.3

m----


31 110

.9 1

.4 3

.9 4

1.3 12

1.3 8

1.3 5

1.3 8







-- 1
1

1


230


30 29

.2 1

.8 1

1.1 6

3.2 4

2.2 11

1.3 1

2.2







.2




257


2.9

5.0

.6

1.8





.3


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nymphaea

Other NAP


Total NAP


11

.4

.4

2.3

1.5

4.3

.4


2.6 9

1.3 2



-- 5





-- 1

.4


2.4

.5



1.3





.2


1.9









.4










Table 2. (continued)


012376 1300


Botryococcus

Pediastrum

Fungal spores


160 cm.
#

276

90

15


180 cm.
% #


8

45

4 3


%

3.5

20

1.3


200 cm.
#i

26

27

14


%

7.0

7.3

3.8


% AP

% NAP


220 cm.
# %

15 5.8

88 34

5 1.9


97

3


012376 1300


Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


240 cm. 260 cm. 280 cm.
# % # % #

171 55 167 64 170

96 31 64 24 64

17 5.4 5 1.9 79

2 .6 -- 3

5 1.6 4 1.5 6

3 1.0 5 1.9 6

10 3.2 10 3.8 5

S 1 .4 5

5 1.6 4 1.5 6

-- -- 1 .4 1

1 .3 -

1 .4 1

-- -- -- -- 1

1 .3



313 262 347
313 262 347


300 cm
#

137

87

10


I.
%

55

35

4.0
--



2.0

3.2


.9

1.7

1.7

1.4

1.4

1.7

.3


1 .4


.3 1

.3 1


250


Total AP


.










Table 2. (continued)


24


012376 1300


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nvmphaea

Other NAP


Total NAP


Botryococcus

Pediastrum

Fungal spores


% AP

% NAP


0 cm. 260 cm. 280 cm. 300 cm.
# % # % # % #

5 1.6 5 1.9 1 .3 13

37 12 20 7.6 6 1.7 90

6 1.9 1 .4 -- -- 4

8 2.6 3 1.2 3 .9 24

1 .3-- -- -- -- -- 1
1 .3 -- -- 1 .3 1


2
-- -- -- -- 1

-- -- -- -- 2

-- -- 1 --


33

2.2

5.1


31

26

1.9


%

5.2

36

1.6

9.6

.4

.4


.0

-- 7


11

22

4.9


17

21

18


320
#

14(

8:


012376 1300

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus


cm. 340 cm. 360 cm.
% # % #

0 57 135 60 132

3 34 71 31 86

2 .8 1 .4 13

1 .4 -- -- 1

3 1.2 1 .4 2

1 .4 3 1.3 1


6.8

8.4

7.2


380 cm.
#

142 6

59 2

2


6

7

.9


%

53

35

5.3

.4

.8

.4


3 1.4









Table 2. (continued)


320 cm. 340 cm. 360 cm. 380 cm.
012376 1300 # % # % # % # %

Carya 9 3.6 10 4.4 8 3.2 5 2.3

Liquidambar 2 .8 -- -- 1 .4 2 .9

Myrica 2 .8 1 .4 1 .4 2 .9

Nyssa 1 .4 4 1.8 1 .4 1 .4

Ilex -- -- -- -- -- -- -- --

Salix

Acer -

Ericaceae -- -- 1 .4 1 .4

Other AP 2 -- -- -- --


Total AP 246 226 248 217


Gramineae 14 5.7 18 8.0 20 8.1 20 9.3

Amaranthus 128 52 134 59 190 77 189 88

Ambrosia 3 1.2 4 1.8 7 2.8 5 2.3

Tubuliflorae 13 5.3 9 4.0 11 4.5 9 4.2

Artemisia -- -- 1 .4 -- -- --

Cyperaceae 1 .4 1 .4 3 1.2 5 2.3

Nuphar -- -- -- -- 2 .8 -- -

Nymphaea -- --

Other NAP -- 4 -- 5


Total NAP 159 171 232 233









Table 2. (continued)


012376 1300


Botryococcus

Pediastrum

Fungal spores


% AP

% NAP


012376 1300


340 cm.
#


2.0

2.4

11


Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nvyssa

Ilex

Salix

Acer

Ericaceae

Other AP


58

27

4.3

.4

2.1

1.4

3.2

2.5

1.1

.4


126

88

2


i2 146

16 78

.8 5

-- 1

2.0 2

2.0 2

2.9 12

.8 2

2.5 2

.4 --


58

31

2.0

.4

.8

.8

4.8

.8

.8


- 2


127 57

73 33

2 .9



4 1.8

1 .4

7 3.2


1 .4


1 .4


-- --1

-- --1


.4 1 .4

-- -- 1


281 245 251


320 cm.
#


360 cm.
#


380 cn
#


1.3

3.0

15


3.2

18

13


1.


3.2

21

13


48

52


400 cm.


420 cm.


440 cm.


460 cm.


# # % % # %


--

2.3

.9


Total AP


222


%"


5









Table 2. (continued)


012376 1300


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nymphaea

Other NAP


Total NAP


Botryococcus

Pediastrum

Fungal spores


400 cm.
#


420 cm.
% # %

2.8 9 3.7

6.4 35 14

1.1 2 .8

1.8 8 3.3


-- --1


.4 1


-- --1


210

96

19


75

34

6.8


9.4

4.9

4.9


% AP

% NAP


012376 1300

Pinus

Quercus

Taxodium


480 cm.
# %

86 34

134 54

9 3.6


490 cm. 500 cm.
# % #

109 48 113

103 46 95

3


%

50

42

1.3


515 cm.
# %

125 58

82 38

3 1.4


- 1 .4 1 .5


460 cm.


440 cm.


2.0

27

1.2

2.8


16

119

8

18


7.2

54

3.6

8.1


1.4

17

12


Carpinus

Ulmus

Fraxinus









Table 2. (continued)


012376 1300

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


Total AP


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemi si:a

Cyperaceae

Nuphar

Nymphaea

Other NAP


480 cm.
#


%

2.8

1.2

2.8

.4







.4
--


15

109

3.6

10

.8

2.4

.4


490 cm.
#


2

3

1

1



1



1

3


226


32

248

7

19

3







12


500 cm.
% #

.9 4

1.3 4

.4 3

.4 1



.4



.4




224


7.1

110

3.1

8.4

1.3


16

341

1

12



3





6


368 324


%

1.8

1.8

1.3

.4


515 cm.

#

1
1

2

1







1


.5

.5

.9

.5







.5


217


7.1

152

.4

5.4



1.3


8.8

56



2.8

.5

.9


Total NAP









Table 2. (continued)


480 cm. 490 cm. 500 cm. 515 cm.
012376 1300 # % # % # % # %

Botryococcus 12 4.8 4 1.8 15 6.7 1 .5

Pediastrum 54 22 39 17 6 2.7 1 .5

Fungal spores 51 20 25 11 31 14 31 14


% AP 40 41 37 59

% NAP 60 59 63 41


520 cm. 540 cm. 560 cm.
012376 1300 # % # % # % # %

Pinus 120 53 196 53 149 53

Quercus 91 40 157 42 118 42

Taxodium 7 3.1 6 1.6 9 3.2

Carpinus -- -- 1 .3 -- --

Ulmus 1 .4 -- -- --

Fraxinus 1 .4 -- -- 1 .4

Carya 1 .4 1 .3 2 .7

Liquidambar -- -- 6 1.6 -- -

Myrica 2 .9 1 .3 1 .4

Nyssa 1 .4 1 .3 1 .4

Ilex -- -- 1 .3 -- --

Salix 1 .4 -- -

Acer -- -- -- -- -- --

Ericaceae -- -- -- 1 .4

Other AP -- -- 1


225 370 283


Total AP









Table 2. (continued)


012376 1300


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nymphaea

Other NAP


Total NAP


Botryococcus

Pediastrum

Fungal spores


420 cm.
#

34

231 1

3

11

6

4

4


%

15

03

1.3

4.9

2.7

1.8

1.8


54




3


0 cm. 560 cm.
# % #

22 5.9 16

59 97 312 1

1 .3 1

5 1.4 30

1 .3 2

4


1 .3


19


407


4.9

2.2

19


8.4

1.1

82


60


425


24

1.8

7.8


% AP

% NAP


012376 1600

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus


0 cm.
#

147

53

46

4

3

7


%

51

18

16

1.4

1.0

2.4


15 cm.
#

115

39

52

4

2

1


3


1


%

50

17

23

1.7

.9

.4


0 cm. 45 cm.
# % # %

52 58 143 67

38 15 45 21

35 13 59 28

1 .4 2 .9

- 1 .5

5 1.9 8 3.8


%

5.7

11

.4

11

.7

1.4


--


3(
1










Table 2. (continued)


012376 1600

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


0 cm.
__ #


Total AP


15 cm.


2.1

1.0



1.7


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nymphaea

Other NAP


Total NAP


.4

.9



.4


.8 3 1.4

5 3 1.4

.8 1 .5

.4 -





.4 -

-1 .5

-- 1


10 9


% #

1.7 5

3.1 5

3.5 3

1.4 4

.3





.7


30 cm.
#

11

10

2

5

1


%

2.2

2.2

1.3

1.7


45 cm.
# %

4 1.9

4 1.9

2 .9

1 .5

-- --



1 .5



2


%

4.2

3.8

.8

1.9

.4


260









Table 2. (continued)


012376 1600


Botryococcus

Pediastrum

Fungal spores


0 cm.
#

32 7.3

5


15 cm.
% # %


30 cm.
#

29

11


1 .3 10 4.3


45 cm.
#


%

114

4.2


%

2.4

.5


2 .8 3 1.4


% AP

% NAP


6 73210 1 600


Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


51

14

14

1.9

.4

1.5

4.8

4.8

1.5

4.8


- 2 .8

- 1 .4

2 .8 1 .4

9 3.7 11 4.5

6 2.5 10 4.1

2 .8 3 1.2

1 .4 1 .4


2 .7


2 .7


-- 2 .8


243 242


60 cm.


75 cm.


90 cm.


105 cm.


# % # % # % # %


67

14

10

.4

.7

.7

1.8

4.3

.4

.7

.4


Total AP


270


012376 1600










Table 2. (continued)


012376 1600


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar


# % # % # %

5 1.9 -- 3 1.2

3 1.1 1 .4 6 2.5


3 1.1


1 .4 5 2.1


-- -- -- --1

-- -- -- --1


Nymphaea

Other NAP


Total NAP


Botryococcus

Pediastrum

Fungal spores


8.9


3 1.1

3 1.1


8.3

1.6

2.9


% AP

% NAP


120 cm.
#


012376 1600

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus


172 E

60 2


22 8

3 1.1

4 1.4

3 1.1


135 cm.
% # %

51 154 58


150 cm.
#


143 57


49 18 70 28

31 12 17 6.7


1.1


165 cm.
% #


181 67

45 17

12 4.5


1 .4 1 .4


.8 -

.8 3 1.1


60 cm.


75 cm.


90 cm.


105 cm.
# %


2 .7


1 .4


12 4.3

7 2.5

2 .7


99

1


1






80


Table 2. (continued)


120 cm. 135 cm. 150 cm. 165 cm.
012376 1600 # % # % # %

Carya 10 3.5 9 3.4 7 2.8 10 3.7

Liquidambar 4 1.4 5 1.9 4 1.6 9 3.3

Myrica 6 2.1 3 1.1 3 1.2 6 2.2

Nyssa -- 5 1.9 1 ..4 -- --

Ilex -- -- -- -- 2 .8 1 .4

Salix -- -- -- -- 1 .4

Acer -- -- -- --

Ericaceae

Other AP -- -- 1


Total AP 284 266 253 269


Gramineae 7 2.5 2 .8 7 2.8 4 1.5

Amaranthus 3 1.1 5 1.9 5 2.0 7 2.6

Ambrosia 1 .4 1 .4 -- -- --

Tubuliflorae 4 1.4 3 1.1 4 1.6 3 1.1

Artemisia -- -- -- -- -- -- 1 .4

Cyperaceae -- -- -- -- -- -- 1 -.4

Nuphar 2 .8 2 .7

Nymphaea -- -- -- -- 1 .4 -- --

Other NAP- -- -- -


Total NAP 15 11 19 17










.Table 2. (continued)


1
012376 1600

Botryococcus

Pediastrum

Fungal spores


% AP

% NAP


1
012376 1600


Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


116 50 140 62 135

84 36 55 24 99

5 2.2 9 4.0 9

1 .4 2 .9 1

2- .9 3 1.3 6

4 1.7 2 .9 1

5 2.2 6 2.7 4

8 3.5 9 4.0 5

2 .9 2 .9 2

3 1.3 -- -- 1

2


-- -- 1

-- -- 1

-- -- 1


51

37

3.4

.4

2.3

.4

1.5

1.9

.8

.4

.8


.4 1


-- 2


230 227 266


20 cm.
#

35

21

3


135 cm.
#

16

10

10


%

6.0

3.8

3.8


%

12

7.4

1.1


150 cm.
#

62

48

12


165 cm.
#

50 1

13

15


%

9

4.8

5.6


%

25

19

4.7


S95

5


80 cm.


195 cm.


210 cm.


225 cm.
# %


58

29

2.4

.8

.8

2.4

2.8

1.2

1.6

.4


Total AP


I










Table 2. (continued)


6 73210 1 600


180 cm.


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

Artemisia

Cyperaceae

Nuphar

Nymphaea

Other NAP


# %

3 1.3

13 5.7


6 2.6


3 1.3



1


6 2.7 5 1.9 7

9 4.0 16 6.0 27


2 .9 3 1.2 4
2 .9 3 1.2 4


1 .9


-- --1


Total NAP


Botryococcus

Pediastrum

Fungal spores


% AP

% NAP


012376 1600

Pinus

Quercus

Taxodium

Carpinus

Ulmus

Fraxinus


240 cm.
#

130

80

4

1

3

2


%

57

35

1.8

.4

1.3

.9


255
#

13

6


cm. 270 cm.
% #

8 60 139

9 30 96

2 .9 9

-- -- 1

6 2.6 2

-- -- 7


195 cm


210 cm.


225 cm.


# % # %


2.8

11


41

18

8.7


25

16

4.0


46

17

6.4


33

24

9.2


285 cm.


137 5

88 3

2

3

4


%

50

35

3.3

.4

.7

2.5


.8

1.2

1.6


--


01276 60


# %










Table 2. (continued)


012376 1600

Carya

Liquidambar

Myrica

Nyssa

Ilex

Salix

Acer

Ericaceae

Other AP


Total AP


240 cm.
#


%I

2.2

.4


255 cm.
#

8

1

4

2







1
m--


232


270 cm.
% #

3.5 11

.5 5

1.7 4

.9 1







.5

1


276


%

4.0

1.8

1.4

.4


285 cm.
# %

6 2.4

3 1.2

4 1.6

1 .4









1


Gramineae

Amaranthus

Ambrosia

Tubuliflorae

'Artemisi a

Cyperaceae

Nuphar

Nymphaea

Other NAP


3

20.



2







1


1.3 8

8.8 69

-- 4

.9 2

-- 1

1



.4 --

-- l1


20 86


3.5

30

1.7

.9

.5

.5

--


6.2

21

3.6

5.1



.7


8.4

59

2.4

3.2

.4

.4


21

147

6

2

1

1





1


194


Total NAP


%
2.2

.4










Table 2. (continued)


240 cm. 255 cm. 270 cm. 285 cm.
012376 1600 # % # % # % # %

Botryococcus 112 49 17 7.4 83 30 2 .8

Pediastrum 56 25 3 1.3 10 3.6 24 9.6

Fungal spores 4 1.8 25 11 26 9.4 30 12


% AP 90 73 73 56

% NAP 10 27 27 44


300 cm.
012376 1600 # %

Pinus 132 56

Quercus 85 36

Taxodium 4 1.7

Carpinus -- -

Ulmus 2 .8

Fraxinus 5 2.1

Carva 4 1.7

Liquidambar 2 .8

Myrica 2 .8

Nyssa

Ilex -

Salix

Acer 1 .4

Ericaceae -- -

Other AP -- -


Total AP






85


Table 2. (continued)


300 cm.
012376 1600 # %

Gramineae 15 6.3

Amaranthus 313 132

Ambrosia --

Tubuliflorae 13 5.5

Artemisia -- -

Cyperaceae 4 1.7

Nuphar 1 .4

Nymphaea -- --

Other NAP 8


Total NAP 361


Botryococcus 5 2.1

Pediastrum 15 6.3

Fungal spores 73 31


% AP 40

% NAP 60










Table 3.--Composition of silt fractions.


0 cm. 40 cm. 80 cm.
Core # 012376 1300 # % # % # %
Silt Grains:
Diatoms 708 98 461 100 776 98.5
Sponge spicules 17 2 1 1 12 1.5
Detrital quartz 2 <1 2 <1 2 <1
Reworked grains 0 0 -- -

Diatoms:* 708 461 776
Achnanthes 17 2.4 7 1.5 6 0.8
Anomoeoneis -- -- -- -- --
Campylodiscus -- -- -- --
Cyclotella 2 0.3 3 0.7 -
Cymbella 1 0.1 3 0.7 -- --
Eunotia 14 2.0 9 1.9 6 0.8
Melosira 693 95 422 91.5 748 96.4
Pinnularia -- -- 6 1.3 2 0.2
Stauroneis 1 0.1 4 0.9 8 1.0
Diatoma -- -- -- -- --
Other -- 7 1.5 6 0.8

Sponge Spicules: 17 1 12
Smooth acerate 1 2
Spined acerate 16 1 10
Spherical
Birotulate




*Percentages calculated under this category are calculated as
a percentage of total diatoms.






87



Table 3. (continued)


120 cm. 160 cm. 200 cm.
Core # 012376 1300 # % # % # %

Silt Grains:
Diatoms 474 98.4 878 96.7 820 99.4
Sponge spicules 8 1.6 9 1.0 5 0.6
Detrital quartz -- -- 21 2.3 -- --
Reworked grains -- -- -- -- -- --

Diatoms:* 474 878 820
Achnanthes 4 0.8 4 0.5 23 2.8
Anomoeoneis -- -- -- -- -- --
Campylodiscus -- -- --
Cyclotella 2 0.5 -- -
Cymbella 1 0.3 -- -- 2 0.3
Eunotia 9 1.9 19 2.2 23 2.8
Melosira 442 92.8 848 96.6 767 93.6
Pinnularia 10 2.1 4 0.4 -- --
Stauroneis 2 0.5 -- --
Diatoma -- -- -- -- -- --
Other 4 0.8 3 0.3 5 0.6

Sponge Spicules 8 9 5
Smooth acerate
Spined acerate 8 9 5
Spherical
Birotulate



*Percentages calculated under this category are calculated
as a percentage of total diatoms.










Table 3. (continued)


240 cm. 280 cm. 320 cm.
Core # 012376 1300 # % # % # %

Silt Grains:
Diatoms 792 99.0 412 99.3 693 99.7
Sponge Spicules 7 1.0 2 0.5 2 0.3
Detrital quartz 1 0.2 -- --
Reworked grains -- -- --

Diatoms:* 792 412 693
Achnanthes -- -- 27 6.5 --
Anomoeoneis -- --
Campylodiscus -- --
Cyclotella -- -- 1 0.3 -- --
Cymbella 12 1.5 26 6.2 12 1.8
Eunotia -- -- 13 3.1 -- --
Melosira 777 98.1 312 75.8 655 94.5
Pinnularia -- -- 4 0.9 10 1.4
Stauroneis -- -- 13 3.1 6 0.8
Diatoma -- -- 2 0.6 6 0.9
Other 3 0.4 14 3.4 4 0.6

Sponge Spicules 7 2 2
Smooth acerate 1 2
Spined acerate 6 2
Spherical
Birotulate



*Percentages calculated under this category are calculated as
a percentage of total diatoms.