Florida State University Libraries

Electronic Theses, Treatises and Dissertations The Graduate School

2015 A Study of the Lithological and Petrographical Changes Across the Eocene- Oligocene Transition of the Ocala and Suwannee Formations in Northern Florida and Southern Georiga Kayla Smith

Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] FLORIDA STATE UNIVERSITY

COLLEGE OF ARTS AND SCIENCES

A STUDY OF THE LITHOLOGICAL AND PETROGRAPHICAL CHANGES ACROSS THE

EOCENE-OLIGOCENE TRANSITION OF THE OCALA AND SUWANNEE

FORMATIONS IN NORTHERN FLORIDA AND SOUTHERN GEORIGA

By

KAYLA SMITH

A Thesis submitted to the Department of Earth, Ocean, & Atmospheric Science in partial fulfillment of the requirements for the degree of Master of Science

2015 Kayla Smith defended this thesis on June 24, 2015. The members of the supervisory committee were:

William Parker Professor Directing Thesis

Stephen Kish Committee Member

James Tull Committee Member

The Graduate School as has verified and approved the above-named committee members, and certifies that thesis has been approved with accordance with university requirements.

ii I dedicate this thesis to my parents and friends. Without their encouragement, I would have never embarked on this journey.

iii AKNOWLEDGMENTS

I would like to thank my committee for all the help and support they gave on my endeavors. Dr. William Parker, my major professor, was invaluable in helping me obtain materials and funding for this project as well as giving me the proper guidance needed to complete my research. Without him I could not have finished this work. Dr. Stephen Kish was always willing to lend a helping hand and exceedingly patient with me. Dr. James Tull was helpful in reviewing my manuscript and providing helpful information. Frank Rupert at Florida's Department of Environmental Protection was kind enough to help identify fossils in my samples. To all those that encouraged me to push through in my research, thank you.

iv TABLE OF CONTENTS

List of Tables...... vii List of Figures...... viii Abstract...... x

1. INTRODUCTION...... 1

1.1 Introduction...... 1 1.2 Objectives...... 3 1.3 Area of Study...... 3 1.4 Background...... 4 1.5 Lithologic Units...... 9 1.5.1 Avon Park Formation...... 9 1.5.2 Ocala Limestone...... 9 1.5.3 Bumpnose...... 10 1.5.4 Residuum on Eocene Sediments...... 10 1.5.5 Suwannee Limestone...... 10 1.5.6 Undifferentiated Lower Oligocene Sediments...... 11

2. METHODS...... 12

2.1 Methods...... 12

3. RESULTS...... 14

3.1 Ocala Limestone...... 14 3.2 Bumpnose Member of the Ocala Limestone...... 14 3.3 Marianna Limestone...... 14 3.4 Suwanee Limestone...... 15

4. INFERRED DEPOSITIONAL ENVIRONMENTS...... 25

4.1 Ocala Limestone...... 25 4.2 Suwannee Limestone...... 27

5. DIAGENESIS...... 29

5.1 Dissolution...... 29 5.2 Calcite Cement...... 30 5.3 Dolomitization...... 32 5.4 Dolomite Cement...... 34 5.5 Chert Precipitation...... 35

6. CHANGES ACROSS THE EOCENE-OLIGOCENE BOUNDARY...... 37

v 6.1 Changes Across the Eocene-Oligocene Boundary...... 37

7. SPECULATIONS ABOUT THE GULF TROUGH...... 39

7.1 Speculations About The Gulf Trough...... 39

8. DISCUSSION AND CONCLUSIONS...... 41

8.1 Discussion and Conclusions...... 41

References...... 44

Biographical Sketch...... 51

vi LIST OF TABLES

1 Modified from May (1977) and Schmidt (1983)...... 8

2 Table of wells used in this study throughout Florida and Georgia. Georgia elevations and total well depths are missing due to lost records after the disembodiment of the Georgia Geological Survey...... 13

vii LIST OF FIGURES

1 Stratigraphic column showing the lithostratigraphic units from the Eocene to the Oligocene throughout the Panhandle of Florida (Modified from Braunstein et al., 1988)...... 2

2 Area of study...... 4

3 Major physiographic features of Georgia's and Florida's Coastal Plain. Modified from Scott (2001)...... 6

4 Interpretation of the axis of low area by various authors (Schmidt, 1983). a. Applin (1951), Chen (1965), Pontigo (1982). b. Herrick and Vorhis (1963), Cramer (1974), Arden (1974). c. Toulmin (1952), Weaver and Beck (1977), May (1977). d. Chen (1965). e. Applin and Applin (1944, 1967), Hull (1962). f. Applin and Applin (1967). g. Chen (1965)...... 9

5 These cross-sections show the textures at the Eocene-Oligocene Boundary in Florida between the Bump Nose Member of the Ocala Limestone in Jackson County and between the Ocala Limestone and Suwannee Limestone in Leon, Madison, and Suwannee counties...... 16

6 These cross-sections show the Eocene-Oligocene Boundary between the Ocala Limestone and Suwannee Limestone throughout Colquitt, Thomas, and Brooks counties in Georgia. Elevation data is unknown...... 17

7 Depth from top of core versus Percent Porosity for Jackson County, FL. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error...... 18

8 Depth from top of core versus Percent Porosity for Leon County, FL. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error...... 19

9 Depth from top of core versus Percent Porosity for Madison County, FL Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error...... 20

10 Depth from top of core versus Percent Porosity for Suwannee County, FL. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error...... 21

11 Depth from top of core versus Percent Porosity for Colquitt County, GA. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error...... 22

12 Depth from top of core versus Percent Porosity for Thomas County, GA. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error...... 23

13 Depth from top of core versus Percent Porosity for Brooks County, GA. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error...... 24

viii 14 Fossilized rhodolith, common throughout the study area in both the Ocala Limestone and Suwannee Limestone. Was taken from Well # 15515 at 229 ft depth. Bar represents 1,500 microns...... 26

15 This secondary porosity (indicated by arrows) is an effect of dissolution of limestone (pink) due to exposure to groundwater. This picture was taken from Well # 15515 at 226 ft depth. Bar represents 1500 microns...... 29

16 Calcite cement (light pink indicated by arrow) can be seen surrounding the skeletal and peloidal grains in this limestone. This slide was stained with Alizarin Red S. Bar represents 1500 microns...... 31

17 Calcite cement growth habit as a function of Mg/Ca ratio (Folk, 1974)...... 31

18 Shows anticipated growth habits of calcite cement crystals and the environment in which they grow (Moore, 1989)...... 32

19 Unstained portion of Well # 18628 at 248.5 ft depth. It shows sucrosic dolomite with a rhombic mosaic of interlocking crystals. Bar represents 1500 microns...... 33

20 Shown here is pore space (white) lined by dolomitic cement. This cement is obvious due to being limpid (clear) and having syntaxial overgrowth of crystals facing in towards open pore space (depicted by arrows). Picture was taken from Well # 18628 at 244 ft depth. Bar indicates 1500 microns...... 34

21 Shown is a microscopic chert nodule (indicated by arrow) that is spherical and shows internal concentric lamination. Picture was taken from Well # 15515 at 228.5 ft depth. Bar indicates 1500 microns...... 36

22 Excavation benches between the Ocala Limestone, the Bumpnose member of the Ocala Limestone, and the Marianna Limestone. The upper brown portion of the picture is the Marianna Limestone while the lower white portion of the picture consists of the Ocala Limestone and the Bumpnose Member of the Ocala Limestone. In the field, it is difficult to discern the difference between the Ocala Limestone and the Bumpnose Member of the Ocala Limestone.The quarry where this picture was taken is called the Marianna Hi Cal Pit and is owned by Leon Brooks. It is located in Jackson County approximately 3 miles northwest of Marianna. Author is for scale...... 38

23 Location of the Gulf Trough through southwestern Georgia. The isopach lines indicate thickness of Miocene to Holocene sediments in feet. The circles with numbers also indicate the thickness of Miocene to Holocene sediments in feet, modified from Herrick and Vorhis (1963)...... 40

24 Cross-section of Early Cretaceous rocks to Miocene rocks. The location of the Gulf Trough is speculated in this graph. (Williams, L.J. and Kuniansky, E.L., 2015)...... 42

ix ABSTRACT

With so few Eocene outcrops throughout Florida, it is difficult to study the Eocene- Oligocene boundary between the Ocala and Suwannee Limestone. This study provides a more detailed lithological description of the differences of rocks on either side of that boundary. In this study, core samples from seven wells throughout northern Florida and Southern Georgia were examined across what is believed to be the Gulf Trough. Samples were cut from the core of each well every six inches for approximately 1.5 feet and then every 1 foot for another 3 feet above and below Eocene-Oligocene boundary picks. The samples were then made into thin sections, stained with Alizarin Red S, examined using a petrographic microscope, described by using both Folk's (1959) and Dunham's (1962) carbonate classification schemes, and fossils were identified where possible. From this information, interpretations of the depositional environment were made. The Ocala Limestone variably consists of biomicritic and pelbiomicritic mudstones, biomicritic packstones, biosparitic grainstones, and dolostones. It consists primarily of white to cream to dark grey and variably fossiliferous limestone. Dolostones are grey to brown and chert is sparse. Fossil assemblages include echinoids, the foraminifera Lepidocyclina sp., Lepidocyclina ocalana, Nummulities sp., and rhodoliths. The Suwannee Limestone wells variably consist of pelmicritic and pelbiomicritic mudstones, pelbiomicritic wackestones, biomicritic packstones, pelbiosparritic grainstones, and dolostones. Dolomite is often grey to brown and chert is common. Fossil assemblages contained in the core from these wells include echinoid fragments and benthic foraminifera such as Lepidocyclina sp. and Nummulities sp. as well as rhodoliths. These findings show that there is minimal variation between the Ocala and Suwannee Limestone aside from the disappearance of the benthic foraminifera Lepidocyclina ocalana, suggesting that a change in environmental conditions was not significant at the Eocene- Oligocene boundary. Based on the lithological descriptions and contained fossil assemblages the Ocala and Suwannee Limestones were deposited in shallow marine environments within the photic zone of the middle marine shelf, such as a Wilson Zone 7 (Wilson, 1975).

x CHAPTER 1

INTRODUCTION

1.1 Introduction

One of the Earth's most dramatic climate change events occurs during the transition between the Eocene and Oligocene. The expansion of glacial ice sheets, a fall in global sea levels, global cooling, and terrestrial aridification were triggered by the changes in the ocean current circulation and large-scale ecological turnovers were seen across nearly all major faunas (Gee et al, 2014). Despite the large scale of the turnover, the extinction event was relatively small in comparison to the largest mass extinction which was at the end of the Permian when approximately 60 to 65% of marine families and genera went extinct (Raup and Sepkoski, 1986). It is estimated that only about 20% of all marine life went extinct at the Eocene-Oligocene Boundary (Prothero, 1994). Although this time is marked by a major climate change, especially that of cooling, opinion is divided as to what caused the climate transition. There are, however, two hypotheses that try to explain the global cooling and, consequently, the abrupt growth of ice sheets during the Eocene-Oligocene transition. The two hypotheses are thermal isolation of Antarctica due to southern ocean gateway opening, and declining atmospheric CO2 (Goldner et al., 2014). “Increases in ocean thermal stratification and circulation in proxies across the Eocene-Oligocene transition have been interpreted as a unique signature of gate way opening, but at present both mechanisms remain possible,” (Goldner et al., 2014). In Florida and Georgia, this change is seen in a sea level drop and a transition of fauna away from the tropical biota associated with the early Cenozoic. For example, the foraminifera Lepidocyclina ocalana, which is widely abundant in the Eocene Ocala Formation disappears prior to the deposition of the Oligocene Suwannee Formation. In the Oligocene, there are greater clastic influxes, principally from the southeastern coastal plain, although sedimentation in Florida and Georgia remained dominated by carbonates. The changes in climate, sediments, and biota are reflected in the stratigraphic transition from limestone of the Ocala Formation to the limestone of the Suwanee Formation. Figure 1 is a stratigraphic column showing the lithostratigraphic units from the older Eocene to the younger Oligocene rocks throughout

1 Florida. It is important to study the transition between Eocene and Oligocene sediments because the boundary between the Ocala Limestone and Suwannee Limestone is not lithologically well defined. Historically, geologists had difficulty distinguishing the various Eocene and Oligocene units because they all have similar lithologic characters therefore the units were defined by the disappearance of Lepidocyclina ocalana. While this may still be significant, it is important to point out that environmental conditions may have become unfavorable for this particular species of foraminifera, thus contributing to its disappearance and may not actually mean a significant change has occurred. It is also important to point out that defining lithological units on the basis of the disappearance of specific fossil species is unacceptable according to the North American Stratigraphic Code (North American Commission of Stratigraphic Nomenclature, 2005). There are also very few exposures in Florida where the boundary can be studied in outcrop. Therefore, studying these formations in thin section from core is necessary.

Figure 1. Stratigraphic column showing the lithostratigraphic units from the Eocene to the Oligocene throughout the Panhandle of Florida (Modified from Braunstein et al., 1988).

A key feature that may affect the lithologic character of units in southern Georgia and in northwestern Florida is the Gulf Trough. The Gulf Trough is a remnant of the older Suwannee Straits, which extends from the Appalachicola Embayment to South Georgia Embayment. “The Suwannee Straits effectively separated the siliciclastic facies to the north from the carbonate facies to the south during the Early Cretaceous,” (Scott, 1988). The renewed uplift of the

2 Appalachian Mountains to the north and their subsequent erosion allowed for siliciclastic sediments to be transported southward by means of rivers and streams. By the end of the Oligocene and early Miocene, the Gulf Trough was completely filled with sediments allowing for siliciclastic sediments to begin reaching the Florida Platform. “The Florida Platform lies on the south-central part of the North American Plate, extending to the southeast from the North American continent separating the Gulf of Mexico from the Atlantic Ocean,” (Scott, 2001). The exposed part of the Florida Platform contains the modern day Florida Peninsula. The influx of siliciclastic sediments from the Appalachian Mountains is thought to be among the reasons why it is so difficult to correlate by lithology across the Gulf Trough. Correlation of lithological units in these areas has been difficult to achieve due to the Gulf Trough supposedly containing a separate suite of lithostratigraphic units and causing “pronounced differences in elevations of Oligocene formations” within the trough compared to on either side of it (Huddlestun 1993).

1.2 Objectives

The objective of this study is to determine vertical and lateral changes in lithology and infer depositional environments, changes in diagenesis (associated with possible exposure to meteoric water dissolution and cementation), and the nature of the stratigraphic transition of the limestones of the Ocala Formation to the Suwannee Formation from a northwesterly to southeasterly direction across the Gulf Trough. With this knowledge, I also expect to be able to reconstruct the paleoenvironment of the area as well as give a detailed diagenetic history of this boundary. The results of this study will be able to address whether there are any significant differences between lithologies of the Ocala and Suwannee Limestones. Also, this study will be able to shed some light on whether the Gulf Trough truly exists.

1.3 Area of Study

Figure 2 below shows the study area. The blue circles on the map show the locations of the core samples from all the wells examined in this study throughout Florida and Georgia. The red triangles show wells in Florida in counties of interest for this study. Although there are numerous drilled wells throughout the study area, the majority have not been drilled deep enough

3 to encompass both Eocene and Oligocene rocks. Wells for this study were picked based on core containment of Eocene and Oligocene rocks, their regional position to include a wide enough range of lateral variation, and their position with regard to the location of where the Gulf Trough is thought to exist. Due to the closing of the Georgia Geological Survey, much of their well data has been lost or destroyed. Therefore, specific location data for wells in Georgia were not found and the points for the Georgia wells in this study were placed directly in the middle of the county in which they reside.

Figure 2. Area of study.

4 1.4 Background

Rifting associated with the Triassic and Jurassic marked the initial opening of the Atlantic Ocean and Gulf of Mexico. It was during this time that the formation of the Coastal Plain occurred. During the Cretaceous and early Paleogene, marine transgressive and regressive cycles were common and were responsible for producing Coastal Plain sediments. During these periods climate in the southeastern United States was warm and humid (Hurst, 1979; Frederiksen, 1980). Temperatures reached their highest in the late Paleocene or early Eocene. It is estimated that during the late Paleocene and early Eocene sea level was approximately 200 to 250 m (650 to 800 ft) higher than it is at present (Haq et al., 1988). There was another marine transgression in the late Eocene, however by the mid-Oligocene, sea level had lowered significantly exposing much of the southeastern Coastal Plain (Huddlestun, 1990). The major physiographic features of Georgia's and Florida's Coastal Plain are shown in Figure 3. Of great interest are the Suwannee Strait and the Gulf Trough. Both features are thought to have controlled marine circulation from the Gulf of Mexico to the Atlantic Ocean as well as influenced patterns of sedimentation. A feature that was key to maintaining carbonate sedimentation on the Florida Platform was a structural low called the Suwannee Strait. It existed from the Middle Cretaceous to the middle Eocene and effectively separated the carbonate Florida Platform from the clastic shelf in the southeastern part of modern North America. The current that swept through the Suwannee Strait beginning in the Middle Cretaceous created a facies boundary between siliciclastics originating from the Appalachian Mountains in the north and the carbonate platform to the south. The current that fed the Suwannee Strait hindered the transport of siliciclastic sediment from the north from interrupting carbonate sedimentation on the Florida Platform. Eventually, the current that once fed the Suwannee Strait weakened and the renewed uplift and erosion of the Appalachian Mountains contributed to the infill of the seaway (Cunningham et al., 2003). The Suwannee Strait served as a channel between Gulf of Mexico and the Atlantic Ocean flowing from the Apalachiacola Embayment to the South Georgia Embayment. By the middle Eocene, the Suwannee Strait had filled with sediment and the Suwannee Current feeding the Suwannee Strait shifted northward to begin flowing through the Gulf Trough (Cocker, 1999).

5 Figure 3. Major physiographic features of Georgia’s and Florida’s Coastal Plain. Modified from Scott (2001).

6 “The Gulf Trough is a major subsurface low on the top of the middle Eocene Claiborne Group, the upper Eocene Ocala Limestone, and the Oligocene Suwannee Limestone,” (Popenoe et al., 1987). From the Appalachicola Embayment, it trends diagonally northeastward approximately 400 km (250 mi) to the Georgia Embayment. The Gulf Trough is deepest in central Georgia and the Ocala Limestone is more than 250 m deeper inside the trough than it is to the north or south of it (Popenoe et al., 1987). During the Miocene, the Gulf Trough continued to fill with sediments and eventually the Suwannee Current changed flow directions (Huddlestun, 1990). Despite the common micro- and macro-fossiliferous Oligocene strata in the southeastern United States, precise and detailed biostratigraphic and chrono-stratigraphic correlation between the panhandle of Florida and the Florida Platform in Georgia and Florida has been difficult to achieve (Huddlestun, 1993). This is because the Gulf Trough contains a separate suite of lithostratigraphic units, distinct from that of the continental shelf to the west and north, and distinct from that of the Florida Bank to the east and south (Huddlestun, 1993). “There are also pronounced differences in elevations of the Oligocene formations within the Gulf Trough compared with elevations of the correlative formations outside the trough,” (Huddlestun, 1993). Because of this, correlation by lithology and stratigraphic position is unreliable between formations within the trough and those on either side of it as well as between formations across the trough. It is important to note that the Gulf Trough has been referred to by many different names. May (1977) addressed the nomenclature issue and gave a concise summary of the various names found in the literature referring to this feature. May (1977) also went on to suggest that the nomenclature issue be solved by re-adopting the original term Chattahoochee Embayment for this physiographic feature in northwest Florida. Below is Table 1 that May (1977) and Schmidt (1983) created that summarizes the different names used for the Gulf Trough since its discovery. Because so many people have studied what is now known as the Gulf Trough, it is no surprise that there are varying opinions as to how the feature formed. Various authors have hypothesized the Gulf Trough was formed by a graben, a downfaulted embayment, a syncline, a solution valley, a submarine valley, or a current-swept strait. With multiple authors hypothesizing about the Gulf Trough's origin comes several interpretations of axial plots. Combining those axial plots on one map shows that there's a wide range of orientation and location (Schmidt,

7 1983). “The immediate question that arises is, are these various authors mapping different feathers or does their stratigraphic interpretation differ significantly from one another,” (Schmidt, 1983)? Table 1. Modified from May (1977) and Schmidt (1983) Johnson 1891 Chattahoochee Embayment Dall and Harris 1892 Suwannee Strait Foerste 1893 Okefenokee Strait Pressler 1947 Apalachicola Embayment of the Gulf Basin Toulmin 1955 Apalachicola Embayment Braunstein 1957 Suwannee River Basin Murry 1957 Southwest Georgia Basin King 1961 Suwannee Basin Roberts and Vernon 1961 Southwest Georgia Embayment Herrick and Vorhis 1963 Gulf Trough of Georgia Sever 1966 Gulf Trough Stringfield 1966 Apalachicola Basin

Because of the confusion various nomenclature and interpretations create, Patterson and Herrick (1971) authored a paper entitled “Chattahoochee Anticline, Apalachicola Embayment, Gulf Trough and Related Structural Features, Southwestern Georgia: Fact or Fiction” that raises the question of whether the feature truly exists at all. Also depending upon the particular rock formation or location studied, the origin of the feature was interpreted differently (Schmidt, 1983). For example, Arden (1974), Applegate et al. (1978), Herrick and Vorhis (1963), Cramer (1974), Outler (1979), Pontigo (1979), Applin and Applin (1944, 1967), and Hull (1962) interpreted their results to mean that a graben caused sediment thickening throughout the Mesozoic sediments and thus placed an axis through Port St. Joe. Other studies place the axis of this feature farther east on Paleogene horizons and is interpreted to be an area where little to no deposition occurred due to a current swept strait (Chen, 1965; Toulmin, 1952; Weaver and Beck, 1977; Gelbaum and Howell, 1979; and May, 1977). Lastly, an interpretation of many (Banks and Hunter, 1973; Toulmin, 1952; and Schmidt, 1983) suggested the feature was formed during the Neogene because of sediment infill of an embayment by a prograding clastic deltaic sequence. Figure 4 shows interpretation of the axis of low area compiled from various authors.

8 Figure 4. Interpretation of the axis of low area by various authors (Schmidt, 1983). a. Applin (1951), Chen (1965), Pontigo (1982) b. Herrick and Vorhis (1963), Cramer (1974), Arden (1974) c. Toulmin (1952), Weaver and Beck (1977), May (1977) d. Chen (1965) e. Applin and Applin (1944, 1967), Hull (1962) f. Applin and Applin (1967) g. Chen (1965)

1.5 Lithologic Units

1.5.1 Avon Park Formation. The oldest known exposed sediments in Florida are the carbonates from the Avon Park Formation. This formation crops out on the Ocala Platform in Levy and Citrus Counties. In 1944, Applin and Applin were the first to describe these Eocene sediments. The Avon Park Formation consists of limestone that is cream to tan in color and variably fossiliferous. Fossil mollusks, formanifera, echinoids, algae, and carbonized plants are often present throughout the Avon Park Formation (Scott, 2001). 1.5.2 Ocala Limestone. The exposed limestones near Ocala in Marion County were first referred to as Ocala Limestone by Dall and Harris in 1892. After recognizing its assemblage of foraminiferal faunas, Puri (1953, 1957) elevated the Ocala Limestone to group status. In accordance with the North American Stratigraphic Code (North American Commission on

9 Stratigraphic Nomenclature, 1983), Scott, in 1991, reduced the Ocala Group to formational status. “The Ocala Limestone is at or near the surface within the Ocala Karst District in the west- cenrtral to northwestern peninsula and within the Dougherty Plain District in the north-central panhandle,” (Scott, 2001). The Ocala Limestone can be divided into a lower and upper facies. The lower facies consists of “white to cream-colored, fine to medium grained, poorly to moderately indurated, very fossiliferous limestone (grainstone and packstone),” (Scott, 2001). The lower facies may not always be present and can be either partially or completely dolomitized some regions (Miller, 1986). The upper facies of the Ocala Limestone “is a white, poorly to well indurated, poorly sorted, very fossiliferous limestone (grainstone, packstone, and wackestone), (Scott, 2001). Chert is common. Fossil assemblages present include large and small foraminifera, echinoids, bryozoans, and mollusks. Lepidocyclina sp. is common in the upper facies while sparse in the lower facies, (Scott, 2001). 1.5.3 Bumpnose. Cooke (1915) first named the Bumpnose in a section of the Crystal River formation of the Ocala Group. Moore (1955) describes the Bumpnose limestone as “a soft, easily crumbled white limestone that is . . . granular . . . because of the presence of many Bryozoa and Foraminifera. It is generally somewhat glauconitic, especially near the top of the member.” Its thickness varies from 0 to 15 feet in Jackson County, Florida and thins to the southeast where it is replaced by the Gadsden Limestone (Moore, 1955). Large foraminifera such as Lepidocyclina sp. are abundant. Bryozoa and mollusk molds are also present in large numbers (Moore, 1915). 1.5.4 Residuum on Eocene Sediments. “The post-Eocene residuum lying on Eocene sediments in the panhandle consists of reddish brown, sandy clays and clayey sands with inclusions of weathered Eocene limestones. Some of the inclusions are silicified carbonates” (Scott, 2001). 1.5.5 Suwannee Limestone. The Suwannee Limestone is visible in outcrop on the northwestern, northeastern, and southwestern flanks of the Ocala Platform. It is absent east of the Ocala Platform due to erosion or nondeposition (Bryan, 1991). Originally named by Cooke and Mansfield (1936), the Suwannee Limestone consists of white to cream-colored, poorly to well indurated, fossiliferous grainstones and packstones. Dolostones within the Suwannee Limestone are grey to tan to brown in color, moderately to well indurated, crystalline dolomite. Chert is

10 common and fossils present include mollusks, foraminifera, corals, and echinoids (Scott, 2001). 1.5.6 Undifferentiated Lower Oligocene Sediments. These sediments consist of white to cream colored, variably fossiliferous limestones. In some sediments, glauconite is present and siliciclastics are a minor components found in some of the sediments (Scott, 2001).

11 CHAPTER 2

METHODS

2.1 Methods

Core from selected wells throughout northern Florida and southern Georgia were examined and described in hand sample at the core repositories archived in their respective states. Of these selected wells, samples from core were taken at 6 inch intervals for 1.5 feet above and below the Eocene-Oligocene boundary and then at 1 foot intervals for another 3 feet above and below the boundary. In Florida, the boundary was based on the Florida Geological Survey's picks for the contact between the Ocala Limestone and Suwannee Limestone. These picks were based on the disappearance of Lepidocyclina ocalana. In Georgia, the same criteria found in Florida's wells was used for making boundary picks. Lepidocyclina ocalana has a slightly sellaeform test that is medium sized and flattened. This species is typically 15 to 20 mm in diameter. One side of the test is “prominently umbonate in the central portion, thence gradually sloping to the periphery,” (Ellis and Messina, 1940). The other side is thickened in the center but is not evenly curved from one side to the other. The sellaeform shape is more clearly visible on the umbonate side. Due to unequal erosion of the other layer of lateral chambers, the surface tends to be smooth or somewhat scrobiculate (Ellis and Messina, 1940). Lepidocyclina ocalana has a vertical section filled with chambers of the equatorial zone. They increase slightly with height toward the exterior. The lateral chambers are compressed, broad, and very low containing a vertical column in the umbonal region. It contains pillars that are well distributed throughout its test except for in the peripheral regions (Ellis and Messina, 1940). Many of the cores archived in Florida were not drilled to depths that reached the boundary between Eocene and Oligocene rocks, therefore a large portion of core was not useful for this study. Once it was determined which cores reached the depths of the Eocene-Oligocene boundary, core was then chosen based on being located far enough apart to ensure regional coverage. In Georgia, there were significantly fewer cores to choose from due to lost samples since the closing of the Georgia Geological Survey. Core samples in Georgia were chosen based on the

12 depth of which they were drilled which needed to be deep enough to contain Eocene and Oligocene rocks. Since there was limited information on these wells, it was necessary to obtain lithological descriptions of neighboring wells in the same counties to determine where the boundary may lie. Cores were also chosen based on proximity to northern Florida county wells and proximity to where the Gulf Trough is thought to have existed. Once samples were obtained, they were then made into thin sections. The thin sections were then stained with Alizarin Red S, examined using a petrographic microscope, and described by using both Folk's (1959) and Dunham's (1962) carbonate classification schemes. Fossil species were identified where possible and percent porosity was estimated. Stratigraphic columns and percent porosity versus depth were then graphed for each well to determine boundary correlations moving across the study area. Table 2 shows the wells that were used in this study.

Table 2. Table of wells used in this study throughout Florida and Georgia. Georgia elevations and total well depths are missing due to lost records after the disembodiment of the Georgia Geological Survey. Well # County State Latitude Longitude Elevation (ft) Total Well Depth (ft) 18427 Jackson Florida 30.795833 -85.259444 196.8 203.0 18628 Leon Florida 30.336944 -84.219444 27.4 250.0 15515 Madison Florida 30.603422 -83.546114 141.0 287.0 18611 Suwannee Florida 29.937500 -82.916389 36.3 206.0 3196 Colquitt Georgia unknown unknown unknown unknown 3215 Thomas Georgia unknown unknown unknown unknown 3209 Brooks Georgia unknown unknown unknown unknown

13 CHAPTER 3

RESULTS

3.1 Ocala Limestone

In Florida, the Ocala Limestone variably consists of biomicritic packstones, biosparitic grainstones, and dolostones. Hand samples show that the limestone is white to cream to light grey in color and abundantly fossiliferous. Dolomite is often grey to brown. Chert is sparse. Predominate fossil assemblages include echinoids, Lepidocyclina sp., Lepidocyclina ocalana, Nummulities sp., and rhodoliths. Rhodoliths are “free-living structures composed (>50%) of non- geniculate coralline algae,” (Foster, 2001). In Georgia, the Ocala Limestone consists of biomicritic and pelbiomicritic mudstones, biomicritic packstones, and dolostones. It consists primarily of white to cream to dark grey and variably fossiliferous limestone. Dolomite is often grey to brown. Chert was only found in the Colquitt county well. Fossils found in these counties include echinoid fragments, Lepidocyclina sp., Lepidocyclina ocalana, Nummulities sp., and rhodoliths.

3.2 Bumpnose Member of the Ocala Limestone

Jackson County, Florida contains an upper unit of the Ocala Limestone called the Bumpnose. In Jackson County, the Bumpnose consists entirely of biomicritic and biopelmicritic packstones. It is approximately 15-25% glauconitic. Fossil assemblages within this well include mollusks, bryozoa, echinoids, Lepidocyclina ocalana, Lepidocyclina sp., Nummulities sp., and Myogypsina sp.

3.3 Marianna Limestone

In Jackson County, Florida the only samples taken that were of Oligocene age were from the Marianna Limestone, which consists of biomicritic wackestones. Hand samples show that this formation is white to cream colored with the occasional rust colored specks throughout. Predominate fossil assemblages include Lepidocyclina (Lepidocyclina) mantelli, Nummulites panamensis, echinoid fragments, and bryozoa.

14 3.4 Suwanee Limestone

In Florida, the Suwannee Limestone wells from the counties of Leon, Suwannee, and Madison variably consists of pelbiomicritic wackestones, biomicritic packstones, pelbiosparritic grainstones, and dolostones. Hand samples show that this formation is white to cream to grey colored, abundantly fossiliferous micritic to crystalline limestone. Microscopic chert nodules are also common. It frequently contains brown to grey dolomite. Predominate fossils include mostly echinoid fragments, benthic foraminifera, bryozoa, and red algea. The foraminiferal assemblages in the study wells constained Lepidocyclina sp., Nummulities sp., and Fallotella sp. Rhodoliths were also present in Madison County in Florida. In Georgia, the Suwannee Limestone in wells located in the counties of Brooks, Colquitt, and Thomas consists mostly of pelmicritic and pelbiomicritic mudstones, biomicritic packstones, and dolostones. Hand samples are white to cream to grey variably fossiliferous micritic to crystalline limestone. Chert is commonly present throughout this formation. Predominate fossil assemblages found in well samples from these counties are echinoid fragments and benthic foraminifera such as Lepidocyclina sp. and Nummulities sp. Rhodoliths are also common in Thomas County. Figures 5 and 6 represent cross-sections from west to east in both Florida and Georgia. The lithologic descriptions were derived from the Dunham (1962) carbonate classification system. In Florida, the contact between the Ocala Limestone and Suwannee Limestone is found within packstones. The “x” areas within Jackson and Suwannee counties in Figure 5 represent non-sampling for Jackson County and no recovery for the Suwannee County well. The Florida Geological Survey picked the boundary between the Ocala Limestone and Suwannee Limestone to be in the areas favored in the stratigraphic columns as correlating to the disappearance of the large foraminifera Lepidocyclina ocalana. In Georgia, there are no textual patterns so the boundary was picked using the same criteria used in the Florida wells, which was the disappearance of Lepidocyclina ocalana. Figures 7-13 represent percent porosity versus depth within each county studied. Error bars have been added to each graph to show that the original visual gauge of porosity could be incorrect by up to 12% porosity difference. There does not appear to be any pattern of porosity change associated with the Eocene- Oligocene boundary.

15 16 17 Figure 7. Depth from top of core versus Percent Porosity for Jackson County, FL. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error.

18 Figure 8. Depth from top of core versus Percent Porosity for Leon County, FL. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error.

19 Figure 9. Depth from top of core versus Percent Porosity for Madison County, FL Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error.

20 Figure 10. Depth from top of core versus Percent Porosity for Suwannee County, FL. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error.

21 Figure 11. Depth from top of core versus Percent Porosity for Colquitt County, GA. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error.

22 Figure 12. Depth from top of core versus Percent Porosity for Thomas County, GA. Red line depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error.

23 Figure 13. Depth from top of core versus Percent Porosity for Brooks County, GA. Red lne depicts Eocene-Oligocene Boundary. Error bars represent up to 12% error.

24 CHAPTER 4

INFERRED DEPOSITIONAL ENVIRONMENTS

4.1 Ocala Limestone With the exception of Brooks and Colquitt counties in Georgia, all wells contain fossilized rhodoliths that are of spherical to ellipsoidal shape and show banding that indicates direction of growth. Figure 14 shows a fossilized rhodolith that is common throughout the wells studied. The wells in Brooks and Colquitt counties may have had fossilized rhodoliths, however there has been extensive recrystallization and identification of rhodoliths cannot be certain. Rhodoliths, often referred to as rhodolites or maerl, are “free-living structures composed (>50%) of non-geniculate coralline algae,” (Foster, 2001). The fossil records of rhodoliths are important because they can help register paleoenviromental conditions (Foster, 2001) such as whether deposition occurred in photic zones (Toomey, 1985) as well as depth, sea level, and hydrodynamic conditions (Manker and Carter 1987, Braga and Martin 1988, Macintyre et al. 1991, Iryu 1997). Shape of the rhodoliths is also of great importance for indicating depositional environment due the effects of water motion. Atabey (1998) explains that rhodoliths with “sphereoidal shapes are products of high-energy, abundant-light, and shallow environments, those in ellipsoidal shapes are characteristic of intermidiate-light and low-energy environments, and finally the ones with discoidal shapes reflect durable, low-energy environments with lesser amounts of light.” The shape of the fossilized rhodoliths suggests that the depositional environment of the Ocala Limestone was exposed to a mixture of low and high energy, shallow marine environment with intermediate-light such as the middle marine shelf, such as a Wilson Zone 7 (Wilson, 1975). All wells within the study area, with the exception of Suwannee County (due to missing sections and dolomitization of the Ocala Limestone) have Lepidocyclina ocalana fossils. Lepidocyclina ocalana are large benthic foraminifera that have been observed in upper Eocene strata of the Ocala Limestone and the Bumpnose Member of the Ocala Limestone (Scott, 2001). Foraminifera are single celled protists with a hard calcite shell. Due to the abundance of these fossils, they live in the nutrient-rich photic zones within the middle to outer shelf marine

25 environments (Bryan, 2008). The presence of these foraminifera further suggest the depositional environment of the Ocala Limestone was a shallow marine environment such as the middle shelf, which is also Wilson Zone 7 (Wilson, 1975).

Figure 14. Fossilized rhodolith, common throughout the study area in both the Ocala Limestone and Suwannee Limestone. Was taken from Well # 15515 at 229 ft depth. Bar represents 1,500 microns.

With the exception of Thomas and Brooks Counties in Georgia, all wells that contain the boundary between the Ocala Limestone and Suwannee Limestone, the Ocala Limestone consist of packstones, grainstones, and dolostones. The significance of dolostones is examined in the diagenesis section later in this chapter. Packstones and grainstones indicate a high-energy environment and with little to no mud input (Dunham, 1962), which are typical in wells 18427, 18628, 15515, 18611, 3196.

26 4.2 Suwannee Limestone

Thomas County in Georgia and Madison county in Florida have fossil rhodoliths in the Suwannee Limestone. Fossil rhodoliths may have been in Brooks and Colquitt counties in Georgia, however they were not identifiable in these two wells because of extensive recrystallization during diagenesis. Rhodoliths in the other wells are spheroidal in shape suggesting that the depositional environment of the Suwannee Limestone was shallow marine with abundant-light and high wave energy such as middle marine shelf, such as a Wilson Zone 7 (Wilson, 1975). Fossils observed throughout the thin sections of the Suwannee Limestone consist of whole and fragmented Lepidocyclina sp., whole and fragmented Nummulities sp., Textularia sp., Miogypsina sp. and echnoids. Fragmentation of fossils suggests high-energy, shallow-water environmental conditions. Fragmentation is the breakage of shells and other organic skeletal remains and is often a good indicator of depositional environment. Fragmentation occurs most frequently in environments with high water turbulence due to the impact of other skeletal remains, rocks, and/or waves (Parsons and Brett, 1991). With the exception of Thomas and Brooks counties in Georgia, in all wells that contain the boundary between the Ocala and Suwannee Limestones, the Suwannee Limestone consist mainly of biomicritic packstones, pelbiosparritic grainstones, with one section of pelbiomicritic wackestone in Leon county Florida. Brooks County in Georgia has been dolomitized and prior texture cannot be identified. Well 3215 consists entirely of pelbiomicritic mudstone. Due to the lesser amount of mud between the grains, the packstones and grainstones suggest high energy environments such as middle marine shelf. The mudstones observed in the well located in Thomas County, Georgia contain abundant bioclasts and pelloids suggesting that the water in that area was physically separated from higher wave energy by some barrier making the depositional environment there a carbonate subtidal lagoon. Dunham (1962) explains that grainstones are deposited in environments where there is high enough energy to wash the micrite or lime mud out between the grains. This allows sparry calcite to form in its place as cement. Although packstones are still found in higher energy environments, they do not form with the same amount of wave action as grainstones. They need to have sufficiently low enough energy to allow micrite to form the matrix between the grains

27 (Dunham, 1962). Mudstones form in low-energy environments such as a Wilson Zone 7 (Wilson, 1975). Here shelf lagoons are sheltered from high-energy wave action and, therefore, often contain “extensive lime sand and mud banks, with abundant pellets and skeletal fragments (Prothero and Schwab, 1994). The type of rocks that form in shelf lagoons seem to correlate with the limestones observed in Thomas County, Georgia and provide a reasonable explanation of their existence in that area.

28 CHAPTER 5

DIAGENESIS

5.1 Dissolution

All core samples examined in this study exhibit dissolution creating secondary porosity. This is evident because of the void spaces that show secondary porosity due to the dissolution of fossils within the rock. Figure 15 shows the effects of dissolution in thin section.

Figure 15. This secondary porosity (indicated by arrows) is an effect of dissolution of limestone (pink) due to exposure to groundwater. This picture was taken from Well # 15515 at 226 ft depth. Bar represents 1500 microns.

Typically, dissolution occurs when rainwater or groundwater percolates through joints in the limestone. Dissolution is more likely to occur in the rock adjacent to the joints than anywhere else in the rock. As more dissolution occurs the dissolved carbonate is carried away from the rock and a void space begins to gradually form. “Often it produces voids where aragonite or 29 high-Mg calcite fossils were selectively dissolved but the low-Mg calcite matrix persisted,” (Prothero and Schwab, 1994). Selective dissolution is especially common in dolomitized rocks which are prevalent throughout this study area. Dolomite is 6 to 10 times more resistant to dissolution than Mg-rich calcite (Nash et. al, 2012) meaning when exposed to meteoric water conditions, dolomite is less likely to dissolve. Therefore when a rock matrix has been dolomitized but the framework skeletal grains remain calcite, there are often void spaces left in the shape of fossils when dissolution has occurred. Because there is mainly fabric selective porosity throughout all wells examined, this suggests that the dissolved fossils were composed of either aragonite or a high-Mg calcite leaving the low-Mg calcite matrix behind and further suggests that these rocks were exposed to groundwater.

5.2 Calcite Cement

There are several core samples in wells from this study that contain calcite cement. Upon inspection these cements appear to have a crystal structure that varies between an equant and a long fibrous shape. Figure 16 shows calcite cement that has precipitated syntaxially around grains. Calcite cements having this crystal shape suggest influences from both freshwater and brine water (Folk, 1974). Moore (2001) states that calcite cements with an equant structures were formed in freshwater environments whereas calcite cements with long fibrous shapes form in saline environments. In freshwater environments where there is little to no substitution of Mg for Ca ions because of low Mg/Ca ratios, the lattice is able to grow equally on all sides. However, in saline water, Mg/Ca ratios are higher allowing for the more complete substitution of Mg ions of Ca ions. This substitution causes a lattice distortion at the edge of a growing crystal, which ultimately causes the elongation of the crystal as it precipitates (Folk, 1974). Figure 17 illustrates the crystal morphology of calcite cement based on the environment it was formed in. Figure 18 illustrates what diagenetic environment calcite cements are anticipated to form in based on crystal habit.

30 Figure 16. Calcite cement (light pink indicated by arrow) can be seen surrounding the skeletal and peloidal grains in this limestone. This slide was stained with Alizarin Red S. Bar represents 1500 microns.

Figure 17. Calcite cement growth habit as a function of Mg/Ca ratio (Folk, 1974).

31 Figure 18. Shows anticipated growth habits of calcite cement crystals and the environment in which they grow (Moore, 1989).

Although Figure 18 shows a relatively simplistic representation of calcite morphology that can be expected in different diagenetic environments, there are other factors that play into calcite cement morphology. These factors include fluid flow and mineral saturation (Gonzalez et al, 1992), evolutionary crystal growth patterns (Dickson, 1993), and the effects of organics and other components such as silica on the growing surfaces of the crystals (Kitano and Hood, 1965). Regardless of these other influences, “calcite cement morphology can be a useful index to the conditions of precipitation, and a valuable clue to the diagenetic history and porosity evolution of a rock,” (Moore, 2001). Thus, since the crystal structure in Figure 16 varies between an equant and a long fibrous shape it can be interpreted to mean that it was in a mixing-zone where meteoric groundwater came into contact with saline water.

5.3 Dolomitization

Core samples from six out of seven wells in this study show signs of dolomite growth. These sections are characterized by “sugary” rhombic mosaic interlocking crystals that are typically found after sucrosic dolomitization occurs, as well as the lack of deep red staining with Alizarin Red S. Figure 19 illustrates a sucrosic dolomite found in well 18628 and is characteristic among the wells examined in this study. The dolomite present in these wells is considered to have formed by secondary replacement of calcite. There is evidence of this by the presence of allochemical ghosts particles as well as the penetration of dolomite rhombs in some of the allochemical particles.

32 Figure 19. Unstained portion of Well # 18628 at 248.5 ft depth. It shows sucrosic dolomite with a rhombic mosaic of interlocking crystals. Bar represents 1500 microns.

Dolomite rocks or dolostones are “crystalline carbonate rocks that are generally multiphasic systems of both replacive and cementing dolomite,” (Choquette and Hiatt, 2008). With mixing-zone dolomitization “seawater of normal salinity and an Mg-to-Ca ratio of 5:2 is mixed with fresh groundwater near the coastline. The seawater . . . provides enough additional magnesium to supersaturate the brackish groundwater with dolomite,” (Prothero and Shwab, 2004). With limestone's natural porosity, the brackish water is then flushed through its pore spaces by means of groundwater fluctuation which allows for a wider expanse of dolomitization. This model is often applied to ancient dolomitized sequences due to “the inevitability of meteoric influence on shallow marine carbonate sequences, and the fact that these meteoric waters replace and mix with original marine pore fluids in a variety of hydrologic situations,” (Moore, 1989).

33 The presence of dolomite in these wells suggests that the rocks were exposed to meteoric groundwater mixing which lowered the calcium to magnesium ratio to favor calcium dissolution and magnesium precipitation. The mixing-zone dolomitization is favored in this study because there does not appear to be any relationship between the dolomite found with hypersaline brine or evaporites (Prothero and Schwab, 1994) to suggest another explanation for this secondary dolomitization.

5.4 Dolomite Cement

All wells in this study show signs of dolomitic cement which is shown in figure 20 by the unstained (clear) crystals pointing inward towards open pore space. Often, original fabrics in sucrosic dolomites are obscured due to dolomite cement (Choquette and Hiatt, 2008).

Figure 20. Shown here is pore space (white) lined by dolomitic cement. This cement is obvious due to being limpid (clear) and having syntaxial overgrowth of crystals facing in towards open pore space (depicted by arrows). Picture was taken from Well # 18628 at 244 ft depth. Bar indicates 1500 microns.

As stated previously, dolomitization usually has two phases of events which is first the replacement of calcium carbonate with dolomite and then the precipitation of dolomitic cement

34 in the remaining pore spaces which is interpreted to occur post replacive dolomitization. In dolomite rocks that weren't deeply buried, cements are often limpid (clear), have planar faces, and form syntaxial overgrowths on crystals facing pores (Choquette and Hiatt, 2008). However, it is often difficult to recognize true dolomite cements without the use of cathodoluminescence microscopy as they often look very similar to dolomitized precursor calcite cements (Scholle and Ulmer-Scholle, 2003).

5.5 Chert Precipitation

The cores from Madison County, Florida and Colquitt County, Georgia wells contain microscopic chert nodules both above and below the Eocene-Oligocene Transition boundary. This is evident by the spherical masses dispersed throughout thin sections in these wells. These chert nodules do not stain with Alizerin Red S, have a low birefringence, and have radiating desiccation cracks with internal concentric lamination which is shown in figure 21. Chert nodules are formed by diagenentic processes. They form when silica was deposited in one place, dissolved, and transported by ground water to re-precipitate elsewhere (Prothero and Schwab, 1994). “The dissolved silica is derived from a variety of sources: detrital quartz grains that the wind transported onto carbonate banks, sponge spicules, and microplankton skeletons,” (Prothero and Schwab, 1994). Cherts are formed in a number of different environments. These environments include marine, hypersaline lakes, and subaerial exposure surfaces (Knauth, 1979). Sometimes chert precipitation is related to mixing-zones in shallow- marine environments (Flugel, 2004) which also agrees with the inferred dolomitization growth that is found in many of the samples examined in this study. “Replacement of limestone by silica is favored by relatively low temperature, acid solutions, and the presence of CO2. As limestone dissolves, Ca ions are released to promote the precipitation of colloidal silica,” (Lovering, 1962). The presence of chert in these wells suggests that at the time of chert precipitation the limestones were of shallow-marine water origins and in direct contact with circulating groundwater also suggesting a mixing-zone.

35 Figure 21. Shown is a microscopic chert nodule (indicated by arrow) that is spherical and shows internal concentric lamination. Picture was taken from Well # 15515 at 228.5 ft depth. Bar indicates 1500 microns.

36 CHAPTER 6

CHANGES ACROSS THE EOCENE-OLIGOCENE BOUNDARY

6.1 Changes Across the Eocene-Oligocene Boundary

The disappearance of the benthic foraminifera, Lepidocyclina ocalana, is the biggest change across the Eocene-Oligocene boundary. By the time the Oligocene Suwannee Limestone was deposited, Lepidocyclina ocalana had completely disappeared. Both sides of the boundary appear to have various benthic foraminifera such as other Lepidocyclina sp. and Nummulities sp. However, overall, it appears that Lepidocyclina ocalana may have died out or evolved into another species due to a change in environmental condition. The Oligocene is marked by a change in global temperatures and sea level, however, based on benthic foraminifera and rhodolith fossils, which thrived in the photic zones of the middle marine shelf, it is not evident that the change in temperature was significant. Although there are significantly more rhodolith fossils found in the Ocala Limestone, it is not uncommon to find them throughout the Suwannee Limestone in Florida and Georgia as well. Therefore, the changes across the boundary are not substantial where rhodoliths are concerned. Lithologically, the Suwannee Limestone consists of pelbiomicritic mudstones, pelbiomicritic wackestones, biomicritic packstones, pelbiosparritic grainstones, and dolostones. The Ocala Limestone consists of biomicritic and pelbiomicritic mudstones, biopelmicritic, pelbiomicritic, and biomicritic packstones, biosparritic grainstones, and dolostones. There are little to no lithological differences between the Suwannee Limestone and Ocala Limestone. The Ocala Limestone does, however, have an upper member called the Bumpnose. It is only present on the western side of the “Gulf Trough” in Jackson County, Florida. Here, the limestone is glauconitic and contains mollusks, bryozoa, echnoids, Lepidocyclina ocalana, Lepidocyclina sp., Nummulities sp., and Myogypsina sp. There are no glauconitic sections of the Ocala Limestone located east of the “Gulf Trough.” Visible in the quarry called Marianna Hi Cal Pit are excavation benches between the Ocala Limestone, the Bumpnose member of the Ocala Limestone, and the Marianna Limestone which are shown in figure 22. The quarry is located in Jackson County, Florida approximately 3 miles northwest of Marianna. These benches represent hardness changes between the lithology with the Bumpnose member being noticeably harder

37 than the rest of the Ocala Limestone. The Marianna Limestone, also found in Jackson County, contains Lepidocyclina (Lepidocyclina) mantelli, echnoid fragments, and bryozoa.

Figure 22. Excavation benches between the Ocala Limestone, the Bumpnose member of the Ocala Limestone, and the Marianna Limestone. The upper brown portion of the picture is the Marianna Limestone while the lower white portion of the picture consists of the Ocala Limestone and the Bumpnose Member of the Ocala Limestone. In the field, it is difficult to discern the difference between the Ocala Limestone and the Bumpnose Member of the Ocala Limestone.The quarry where this picture was taken is called the Marianna Hi Cal Pit and is owned by Leon Brooks. It is located in Jackson County approximately 3 miles northwest of Marianna. Author is for scale.

38 CHAPTER 7

SPECULATIONS ABOUT THE GULF TROUGH

7.1 Speculations About The Gulf Trough

According to previous authors (Herrick and Vorhis, 1963), the axis of the Gulf Trough goes directly through the center of Colquitt County, Georgia as show in Figure 23. Although the exact location of the well used in this study in Colquitt County, Georgia is unknown, due to lost location data, the depth of the Eocene-Oligocene boundary suggests that it is located within the trough itself. The depth of the Eocene-Oligocene boundary in Colquitt County, Georgia in well 3196 is at 745.5 feet below the surface (see following discussion). This is approximately 450 feet deeper than the neighboring wells of Thomas and Brooks counties which are at 289.5 feet and 297 feet below the surface (see following discussion), respectively. It is important to point out the limitations of this data. The depths of the Eocene-Oligocene Boundary in the Georgia wells are presumably depth from the surface however wellhead elevations in these counties are unknown. Therefore, it is possible that the depth differences may not be significant if Colquitt County, Georgia well is at an exceptionally high elevation in comparison to wells in neighboring counties. The highest elevation in Colquitt County, Georgia is 410 feet above sea level where as the highest elevations in Brooks and Thomas counties the highest elevations are 290 feet and 350 feet above sea level, respectively. It is possible that of the wells were drilled in valleys within Brooks and Thomas counties, thus accounting for the depth differences between the wells. Huddlestun (1990) proposed that the Suwannee Current stopped feeding the Gulf Trough as it filled up with sediment during the Miocene. The question now is, if location maps of the Gulf Trough are correct, does the well in Colquitt County, Georgia provide evidence to suggest that the Gulf Trough did, in fact, exist by the late Eocene in the Ocala Limestone? Both the Ocala and Suwannee Limestones contained in the core of this well consist entirely of packstones. Packstones form within high-energy environments on the middle marine shelf. Here, the wave energy, although still high, is sufficiently low enough for micrite to form the matrix between the grains. The fossil assemblages of both whole and fragmented foraminifera suggest a high-energy environment was needed to create the fragmented skeletal

39 grains giving further supporting evidence of a middle shelf marine environment and not a deeper environment that would be thought to occur in a trough. The presence of rhodoliths give even more evidence to suggest shallow water, middle shelf marine environment.

Figure 23. Location of the Gulf Trough through southwestern Georgia. The isopach lines indicate thickness of Miocene to Holocene sediments in feet. The circles with numbers also indicate the thickness of Miocene to Holocene sediments in feet, modified from Herrick and Vorhis (1963).

40 CHAPTER 8

DISCUSSION AND CONCLUSIONS

8.1 Discussion and Conclusions

The conclusions from this study are that there are no major lithologic changes across the Eocene-Oligocene Boundary of the Ocala Limestone and Suwannee Limestone except in Jackson County, Florida. The difference of fossil assemblages in Jackson County can be accounted for by shallower bathymetry being at shallower depths thus supporting different fauna. The difference in hardness of the lithology between the Ocala Limestone and Bumpnose member can be accounted for by exposure to meteoric influences which allows for the precipitation and growth of cement. Due to the absence of lithologic differentiation between the Ocala Limestone and Suwannee Limestone in this study, it is my conclusion that both formations were deposited under the same environmental conditions. Furthermore, it would be wise to be cautious when attempting to establish the boundaries between the Ocala and Suwannee Limestones based on lithology. Perhaps, as further investigations unfold, lithologic nomenclature should be revised to use a single name. Based on the core described from the Colquitt County, Georgia well, there is no evidence to suggest this well location was within the Gulf Trough during the late Eocene or early Oligocene and, consequently, the Gulf Trough did not exist until after the deposition of the Suwannee Limestone in early Oligocene. However, the question of why the Eocene-Oligocene boundary is so much deeper in this well than it is in neighboring wells remains. It is my suggestion that if it existed at all, the Gulf Trough formed after Oligocene sediments were deposited. Thus, any later sedimentation acted upon previous deposits by causing subsidence of the region which explains the “pronounced differences in elevations” (Huddlestun, 1993) of the Eocene-Oligocene boundary between this Colquitt county well and neighboring wells in Thomas and Brooks counties. To provide further evidence of the possibility that the Gulf Trough did not exist until at least after Oligocene sediments were deposited, there are two things to consider. First of all, in the area where the subsidence supposedly took place, is there evidence of other contacts being shifted down as well? And secondly, is there evidence of thicker sediments occurring at this

41 location at any other time in the stratigraphic interval to suggest that the Gulf Trough may have been present at another time?

Figure 24. Cross-section of Early Cretaceous rocks to Miocene rocks. The location of the Gulf Trough is speculated in this graph. (Williams, L.J. and Kuniansky, E.L., 2015).

Figure 24 sheds light onto the first question by showing that the strata in Georgia do in fact contain Eocene and Oligocene aged rocks that have been displaced downward in the area

42 where the Gulf Trough is thought to have existed. Therefore, this gives evidence to the possibility that the Gulf Trough may not have existed until after Oligocene sediments were deposited. The figure also shows that Miocene aged rocks are only slightly thicker in Georgia near where the axis of the Gulf Trough is thought to be. It is possible that if the Gulf Trough existed it formed due to differential subsidence after Oligocene sediments were deposited. This subsidence could have been caused by the de-watering of older rocks throughout the Cretaceous and early Paleogene. Due to the implications this study makes, further studies should be undertaken to once and for all put to rest whether the Gulf Trough truly existed at all and, if so, determine what part of geologic history it is restricted to.

43 REFERENCES

Applegate, A.V., Pontigo, F.A. Jr., and Rooke, J.H., 1978, Jurassic Smackover Oil Prospects in the Apalachicola Embayment: The Oil and Gas Journal, January, 1978, v. 76, n. 4, p. 80- 84.

Applin, P.L., 1951, Preliminary Report on Buried Pre-Mesozoic Rocks in Florida and Adjacent States: United States Geological Survey Circular 91, 28 p.

Applin, P.L., and Applin, E.R., 1944, Regional subsurface stratigraphy and structure of Florida and southern Georgia: American Association of Petroleum Geologists Bulletin, v. 28, p. 1673-1753.

Applin, P.L., and Applin, E.R., 1967, The Gulf Series in the Subsurface in Northern Florida and Southern Georgia: United States Geological Survey, Professional Paper 524-G, 34 p.

Arden, D.D., Jr., 1974, A Geophysical Profile in the Suwannee Basin, Northwestern Florida: in Symposium on the Petroleum Geology of the Georgia Coastal Plain, Georgia Geological Survey Bulletin 87, p. 111-122.

Atabey, Nevbarharl, 1998, Facies Characteristics and Geographic Distribution of Rhodoliths and Maerls (Red Algae) in Southern Shelf of the Sea of Marmara: Mineral Resources Exploration Bulletin, v. 20, p. 55-61.

Banks, J.E., and Hunter, M.E., 1973, Post-Tampa, pre-Chipla Sediments Exposed in liberty, Gadsden, Leon, and Wakulla Counties, Florida: Trans. Gulf Coast Association Geological Society, v. 23, p. 355-363.

Braga, J.C. and Martin, J.M., 1988, Neogene Coralline-algal growth-forms and Their Palaeoenvironments in the Almanzora River Valley (Almeria, S.E. Spain): Palaeogeography, Palaeoclimatology, Palaeoecology, v. 67, n. 3-4, p. 285-303.

Braunstein, J., 1957, The habit of oil in the Cretaceous of Mississippi and Alabama: in Frascogna, X. M., Mesozoic-Paleozoic producing areas of Mississippi and Alabama: Mississippi Geological Society, p. 1-11.

Braunstein, J., Huddlestun, P., and Biel, R., 1988, Gulf Coast region correlation of stratigraphic units of North America: American Association of Petroleum Geologists, Correlation Chart.

Bryan, J.R., 1991, Stratigraphic and paleontologic studies of Paleocene and Oligocene carbonate facies of the eastern Gulf Coastal Plain: unpublished Ph.D dissertation, University of Tennessee, Knoxville, TN, 324 p.

Bryan, J.R., 2008, Larger Benthic Foraminiferal Biofacies of the Ocala Limestone: Geological Society of America, Abstracts with Programs, v. 40, no. 4, p. 66.

44 Chen, C.S., 1965, The Regional Lithostratiraphic Analysis of Paleocene and Eocene Rocks of Florida: Florida State Geological Survey Bulletin 45, 105 p.

Choquette, P.W., Hiatt, E.E., 2008, Shallow-burial Dolomite Cement: A Major Component of Many Ancient Sucrosic Dolomites, Sedimentology, v. 55, p. 423-460.

Cocker, M.D., 1999, Coastal plain mineral resources of Georgia: Environments of Deposition, in Johnson, K.S., ed., Proceedings of the 34th Forum on the Geology of Industrial Minerals, 1998: Oklahoma Geological Survey Circular 102, Oklahoma Geological Survey, p. 219-228.

Cooke, C.W., 1915, The age of the Ocala Limestone: United States Geological Survey Professional Paper 95, p. 107-117.

Cooke, C.W., and Mansfield, W.C., 1936, Suwannee Limestone of Florida (abstract): Geological Society of America Proceedings, 1935, p. 71-72.

Cramer, H.R., 1974, Isopach and Lithofacies Analysis of the Cretaceous and Cenozoic Rocks of the Coastal Plain of Georgia: in Symposium on the Petroleum Geology of the Georgia Coastal Plain, Georgia Earth and Water Division Bulletin 87, p. 21-43.

Cunningham, K.J., Locker, S.D., Hine, A.C., Bukry, D., Barron, J.A., and Guertin, L.A., 2003, Interplay of the late Cenozoic siliciclastic supply and carbonate response on the southeast Florida platform. Journal of Sedimentary Research 73.1, p. 31-46.

Dall, W.H., and Harris, G.D., 1892, Correlation papers – Neocene: United States Geological Survey Bulletin 84, 349 p.

Dall, W.H., and Stanley-Brown, 1894, Cenozoic geology along the Apalachicola River: Geological Society of American Bulletin, v. 5, p. 147-170.

Dickson, J.A.D., 1993, Crystal Growth Diagrams as an Aid to Interpreting the Fabrics of Calcite Aggregates, Journal of Sedimentary Research, v. 63, no. 1, p. 1-17.

Dunham, R.J., 1962, Classification of Carbonate Rocks According to Depositional Texture, in Ham, W.E., ed., Classification of Carbonate Rocks: American Association of Petroleum Geologists Memoir, v. 1, p. 108-121.

Ellis, B.R., and Messina, A.R, 1940, et seg. Catalogue of Foraminifera: Washington D.C. (American Museum of Natural History).

Finch, J., 1823, Geological essay on the Tertiary formation in America: American Journal of Science, v. 7, p. 31-43.

Flugel, E., 2004. Microfacies of Carbonate Rocks Analysis, Interpretation, and Application: Berlin, Heidleberg, New York, Springer-Verlag, 643 p.

45 Foerste, A.F., 1893, Studies on the Chipola Miocene of Bainbridge, Georgia and of Alum Bluff, Florida: American Journal of Science, v. 46, p. 245-254.

Folk, R.L., 1974. The Natural History of Crystalline Calcium Carbonate: Effect of Magnesium Content and Salinity, Journal of Sedimentary Petrology, v. 44, p. 40-53.

Folk, R.L., 1959, Practical Petrographic Classification of Limestones: AAPG Bulletin, v. 43, p. 1-38.

Foster, M.S., 2001, Rhodoliths: Between Rocks and Soft Places: Journal of Phycology, v. 37, no. 5, p. 659-667.

Frederiksen, N.O., 1980, Mid-Tertiary Climate of Southeastern United States: The Sporomorph Evidence: Journal of Paleontology, v. 54, no. 4, p. 728-738.

Gee, B., Kraatz, B., Roopnarine, P., and Angielczyk, K., 2014. Terrestrial Community Reorganization During the Eocene-Oligocene Transition Within North America: Geological Society of North America Abstracts with Programs, v. 46, no. 6, p. 133.

Gelbaum, C., and Howell, J., 1979, The Geohydrology of the Gulf Trough: in Second Symposium on the Geology of the Southeastern Coastal Plain, Georgia Geological Survey, Information Circular 53, p. 140-153.

Goldner, A., Herold, N., and Huber, M., 2014. Antarctic Glaciation Caused Ocean Circulation Changes at the Eocene-Oligocene Transition: Nature, v. 511, p. 574-577.

Gonzalez, L.A., Carpenter, S.J., Lohmann, K.C., 1992. Inorganic Calcite Morphology: Roles of Fluid Chemistry and Fluid Flow, Journal of Sedimentary Petrology, v. 62, no. 3, p. 382- 399.

Haq, B.U., Hardenbol, J., and Vail, P.R., 1988, Mesozoic and Cenozoic Chronostratigraphy and Cycles of Sea-Level Change, in Wilgus, C.K., Hastings, B.S., Posamentier, H., Van Wagoner, J., Ross, C.A., and Kendall, C.G.S.C., eds., Sea-Level Changes: An Integrated Approach, S.E.P.M. Special Publication 42: Tusa, Society of Economic Paleontologists and Mineralogists, p. 71-108.

Herrick, S.M., and Vorhis, R.C., 1963, Subsurface Geology of the Georgia Coastal Plain; Georgia Geological Survey, Information Circular 25, 79 p.

Huddlestun, P.F., 1990, The Paleogene of the Northeastern Gulf of Mexico Coastal Plain, in Zullo, V.A., Harris, W.B., and Price, V., eds., Savannah River Region: Transition Between the Gulf and Atlantic Coastal Plains: Wilmington, NC., University of North Carolina, p. 23-24.

Huddlestun, P., 1993. A revision of the Lithostratigraphic units of the coastal plain of Georgia, The Oligocene: Georgia Geologic Survey, Bulletin 105.

46 Huddlestun, P., 1984, The Neogene stratigraphy of the central Florida panhandle: Unpublished Dissertation, Florida State University Department of Geology, Tallahassee, Florida, 210 p.

Hull, J.P.D. Jr., 1962, Cretaceous Suwannee Strait, Georgia and Florida: American Association of Petroleum Geologists Bulletin, v. 46, n. 1, p. 118-122.

Hurst, V., J, ed., 1979, Field Conference on Kaolin, Bauxite and Fuller's Earth, Annual Meeting of the Clay Minerals Society, 107 p.

Iryu, Y., 1997, Pleistocene Fore-reef Rhodoliths from the Ryukyu Islands, Southwestern Japan: Proceedings of the 8th International Coral Reef Symposium, v. 1, p. 749-754.

Johnson, L.C., 1891, The Chattahoochee Embayment: Geological Society of America, Bulletin, v. 3, p. 128-133.

King, P.B., 1961, The Subsurface Ouachita Structural Belt East of the Ouachita Mountains: in Flawn, P.T., et al, The Ouachita Stystm: University of Texas, Austin, p. 83-97.

Kitano, Y. and Hood, D.W., 1965. The Influence of Organic Material on the Polymorphic Crystallization of Calcium Carbonate, Geochimica et Cosmochimica Acta, v. 29, no. 1, p. 29-41.

Knauth, L.P., 1979. A model for the origin of chert in limestones, Geology, v. 7, p. 274-277.

Lovering, T.G., 1962. The origin of jasperoid in limestone, Economic Geology, v. 57, no. 6, p. 861-889.

Macintyre, I.G., Rutzler, K., Norris, J.N., Smith, K.P., Cairns, S.D., Bucher, K.E., and Steneck, R.S., 1991, An Early Holocene Reef in the Western Atlantic: Submersible Investigations of a Deep Relict Reef Off the West Coast of Barbados, W.I.: Coral Reefs, v. 10, no. 3, p. 167-174.

Manker, J.P., and Carter, B.D., 1987, Paleoecology and Paleogeography of an Extensive Rhodolith Facies from the Lower Oligocene of South Georgia and North Florida: PALAIOS, v. 2, p. 181-188.

Matson, G.C., and Clapp, F.G., 1909, A preliminary report on the geology of Florida: Florida Geological Survey Second Annual Report, p. 23-173, 1 plate.

May, J.P., 1977, The Chattahoochee Embayment: Southeastern Geology, v. 18, p.149-156.

Miller, J.A., 1986, Hydrogeologic framework of the Floridan aquifer system in Florida and parts of Georgia, Alabama and South Carolina: United States Geological Survey Professional Paper 1403-B, 91 p.

47 Moore, C., 2001, Carbonate Reservoirs – Porosity Evolution and Diagenesis in a Sequence Stratigraphic Framework: The Netherlands, Elsevier Science B.V., 65 p.

Moore, C., 1989, Carbonate Diagenesis and Porosity: The Netherlands, Elsevier Science B.V., 220 p.

Moore, W.E., 1955, Geology of Jackson County, Florida: Florida Geological Survey, Bulletin 37.

Murray, G.E., 1957, Geologic Occurrence of Hydrocarbons in Gulf Coastal Province of the United States: Trans. Gulf Coast Association and Geological Society, v. 7, p. 253-299.

Nash, M.D., Opdyke, B.N., Troitzsch, U., Russell, B.D., Adey, W.H., Kato, A., Diaz-Pulido, G., Brent, C., Gardner, M., Prichard, J., Kline, D.I., 2012, Dolomite-rich Coralline Algae in Reefs Resist Dissolution in Acidified Conditions: Nature Climate Change, v. 3, n. 3, p. 268-272.

North American Commission on Stratigraphic Nomenclature, 1983, North American Stratigraphic Code: American Association of Petroleum Geologists Bulletin, v. 67, n. 5, p. 841-875.

North American Commission on Stratigraphic Nomenclature, 2005, North American Stratigraphic Code: American Association of Petroleum Geologists Bulletin, v. 89, n. 11, p. 1547-1591.

Outler, B.C., 1979, The Stratigraphy and Environments of Deposition of the Tuscaloosa Formation in Part of panhandle Florida: Thesis, Florida State University, Geology Dept., 66 p.

Patterson, S.H., and Herrick, S.M., 1971, Chattahoochee Anticline, Apalachicola Embayment, Gulf Trough and Related Structural Features, Southwestern Georgia, Fact or Fiction: Geologic Geological Survey, Information Circular 41, 16 p.

Parsons, K.M., and Brett, C.E., 1991, Taphonomic Processes and Biases in Modern Marine Environments: and actualistic perspective on fossil assemblage preservation. In: Donovan SK (ed) The Processes of Fossilization. Belhaven Press, London, 22-65 p.

Pontigo, F.A. Jr., 1979, unpublished Structure contour Map of the Smackover Formation, Northwest Florida: Florida Bureau of Geology.

Pontigo, F.A. Jr., 1982, Pre-Haynesville Stratigraphy and Structural Geology of the Apalachicola Embayment: Petrology and Paleoenvironmental Interpreation of the Smackover Formation: M.S. Thesis, Florida State University, Geology Dept., 307 p.

Popenoe, P., Henry, V.J., and Idris, F.M., 1987, Gulf trough – The Atlantic connection: Geology, v. 15, p. 327-332.

48 Pressler, E.D., 1947, Geology and Occurrence of Oil in Florida: American Association of Petroleum Geologists Bulletin, v. 31, p. 1851-1862.

Prothero, D., 1994, The Eocene-Oligocene Transition Paradise Lost: New York, Columbia University Press, 133 p.

Prothero, D., and Schwab, F., 1994, Sedimentary Geology An Introduction to Sedimentary Rocks and Stratigraphy, 2nd ed.: New York, W.H. Freeman and Company, 233-234, 265, 227 p.

Puri, H.S., 1953, Contribution to the study of the Miocene of the Florida panhandle: Florida Geological Survey Bulletin 36, 346 p.

Puri, H.S., 1957, Statigraphy and zonation of the Ocala Group: Florida Geological Survey Bulletin 38, 248 p.

Raup, D.M, and Sepkoski, J.J., 1986, Periodic extinctions of families and genera: Science, v. 231, p. 833-836.

Roberts, W.L., and Vernon, R.O., 1961, Florida - More Extensive Drilling Might Uncover Big Oil and Gas – Producing Areas: Oil and Gas Journal, v. 59, March 13, 1961, p. 214-219.

Scholle, P.A. And Ulmer-Scholle, D.S., 2003, A Color Guide to the Petrography of Carbonate Rocks: Grains, Textures, Porosity, Diagenesis: Tulsa, OK, The American Association of Petroleum Geologists, 273 p.

Scott, T., 1988. The Lithostratigraphy of the Hawthorn Group (Miocene) of Florida, Florida Geological Survey, Bulletin 59.

Scott, T., 1991, A Geological overview of Florida: in Scott, T.M., Lloyd, J.M., and Maddox, G. (eds.), Florida's Ground Water Quality Monitoring Program- Hydrogeological Framework: Florida Geological Survey Special Publication 32, p. 5-14.

Scott, T., 2001. Text to accompany the geologic map of Florida: Open-file Report 80.

Sever, C.W., 1966, Miocene Structural Movements in Thomas County, Georgia: United States Geological Survey, Professional Paper 550-C p. 12-16.

Schmidt, W., 1983, Neogene Stratigraphy and Geologic History Apalachicola Embayment, Florida: Ph.D. Dissertation, Florida State University, Tallahassee, FL, 128 p.

Stringfield, V.T., 1966, Artesian Water in Tertiary Limestone in the Southeastern States: United States Geological Survey, Professional Paper 517, 226 p.

49 Toomy, D.F., 1985, Paleodepositional Setting of Rhodoliths from the upper Pennsylvanian (Virgil) Salem School Limestone of Northcentral Texas: In Toomey, D.F. & Nitecki, M.H. [Eds.] Paleoalgology: Contemporary Research and Applications. Springer-Verlag, Berlin, 297-305 p.

Toulmin, L.D., 1952, Sedimentary Volumes in Gulf Coastal Plain of the United States and Mexico: Part II Volumes of Cenozoic Sediments in Florida and Georgia, Geological Society of America Bulletin, v. 63, p. 1165-1176.

Toulmin, L.D., 1955, Cenozoic Geology of Southeastern Alabama, Florida, and Georgia: American Association of Petroleum Geologists Bulletin, v. 39, n. 2, p. 207-235.

Veatch, O., and Stevenson, L.W., 1911, Geology of the coastal plain of Georgia: Georgia Geologic Survey Bulletin 26, 466 p.

Weaver, C.E., and Beck, K.C., 1977, Miocene of the S.E United States: A Model for Chemical Sedimentation in a Peri-Marine Environment: Sedimentary Geology, v. 17, n. ½, p. 1- 234.

Webb, S.D., and Crissinger, D.B., 1983, Stratigraphy and vertebrate paleontology of the central and southern Phosphate District of Florida: in Central Florida Phosphate District, Geological Society of America, Southeast Section Field Trip Guidebook, p. 28-72.

Williams, L.J., and Kuniansky, E.L., 2015, Revised hydrogeologic framework of the Floridan aquifer system in Florida and parts of Georgia, Alabama, and South Carolina: U.S. Geological Survey Professional Paper 1807.

Wilson, J.L., 1975, Carbonate Facies in Geologic History: Springer-Verlag, New York, 470 p.

50 BIOGRAPHICAL SKETCH

2013 – 2015 Master of Science in Geology Department of EOAS, Florida State University Tallahassee, FL 32304

2006 - 2009 Bachelor of Science with Options in Geophysics and Geochemistry Department of Geosciences, Virginia Tech Blacksburg, VA 24061

2004 - 2006 Associates Degree in Science Southwest Virginia Community College Richlands, VA 24641

Aug 13 – May 15 Teaching Assistant at Florida State University -Instructor of Dynamic Earth Labs

Oct 10 – July 13 Geological Technician at Range Resources -Oversight of electric logging of Conventional and CBM wells in the field -Sample cataloging -Set baffles for completable zones -Geologic correlations -Determination of net pay of completable formations -Analysis of reserve data -Completion of four day Geographix course -Research on the Utica Shale as a potential target formation in Virginia

May 09 – Sept 09 Lab/Research Assistant at Virginia Tech under guidance of Bojeong Kim -Synthesis of Hematite -Use of potentiometrics to determine silver concentrations

May 08 – Aug 08 Geological Technician Intern at Marshall Miller & Associates -Geotechnical logging of core in the field and laboratory -Fracture logging of core -Roof/Floor capabilities of core -Watershed interpretation for acid mine drainage

May 07 – May 08 Lab/Office assistant at Virginia Tech, Biogeochemistry of Earth Processes -Work with postdoc (Dr. Nizhou Han) in laboratory maintenance -Assist professor with organizing scientific materials (Dr. Patricia Dove) -Taught portion of NSF Outreach program, Earth to Life to 4th graders

51