Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1960 Stratigraphy and Ostracoda of the Ripley Formation of Western Georgia. Raymond Weathers Stephens Jr Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.edu/gradschool_disstheses Recommended Citation Stephens, Raymond Weathers Jr, "Stratigraphy and Ostracoda of the Ripley Formation of Western Georgia. LSU Historical Dissertations and Theses.edu/gradschool_disstheses/587 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons.
For more information, please contact gradetd@lsu. Stratigraphy and Ostracoda of the Ripley Formation of Western Georgia A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirement8 for the degree of Doctor of Philosophy in The Department of Geology by Raymond Weathers Stephens, Jr., University of Georgia, 1951? M, S,, Louisiana State University, 1956 January, I960 ACKNOWLEDGMENTS The writer wishes to express his sincere appreciation to Dr* Glover E. Murray and Dr., Louisiana State University, for their guidance and assistance throughout the preparation of this dissertation and for their time spent with me in both the field and the office* Grateful acknowledgment is due Dr. Howe, Director of the School of Geology, Louisiana State University, far his invaluable assistance in the identification of the Ostracoda and for the generous use of his excellent type collection* Dr.
Fern graciously assisted in the study of the thin sections used in this dissertation and far this the author offers credit and appreciation* Special acknowledgment is due fellow graduate student Steve R. Windham for preparing the Ostracoda illustrations and fellow graduate student Phili Deboo for his aid in mineral identification. The writer is also indebted to the Magnolia Petroleum Company for their graduate fellowship for the years 1957-1959. TABLE OF CONTENTS Page I ABSTRACT.
7 Quitman and Southern Stewart Counties. 8 Northern Stewart, Southern Chattahoochee, and Southern Marion Counties. 12 Central Stewart County. 15 Northern Schley, Southern Taylor, and Northern Macon Counties.
21 Area Between Flint and Ocmulgee Rivers. 21 Cretaceous East of the Ocmulgee River. 35 VII DESCRIPTION OF GENERA AND SPECIES. 37 iii Page Phylum ARTHROPODA.
37 Suborder FLATYCOPA Sars, 1865. 37 Family CYTHERELLIDAE Sars, 1866. 37 Genus CYTHERELLOIDEA Alexander, 1929. 37 Cytherelloidea crafti Sexton,1951.
37 Genus CYTHERELLA Jones, 181*9. 38 Cytherella ovoidea Alexander, 1929. 1*0 Suborder PODOCOPA Sars, 1865. 1*1 Family CYPRIDAE Baird, 181*9.
1*1 Genus ARGILLOECIA Sars, 1866. 1*1 Subfamily CYPRIDINAE Baird, 181*6. 1*1 Genus PARACYPRIS Sars, 1866. Id Paracypris sp.
1*1 Family BAIEDIIBAE Sars, 1923. 1*2 Subfamily BAIRDIINAE Sars, 1923. 1*2 Genus BAIRDOPPHATA Coryell, Sample and Jennings, 193?. 1*2 Bairdoppilata magna Alexander, 1927.
1*2 iv Page Family CYTHERIDAE Baird, 1850. 43 Subfamily XESTOLEBERINAE Sars, 1928.43 Genus XESTOLEBERIS Sars, 1866. 43 Subfamily LOXOCOWCHINAE Sars, 1925. 44 Genus LOXOCONCHA Sars, 1866.
kk Laxoconcha cretacaa Alexander,- 1936. 44 Subfamily CYTHERURINAE Muller, 1894. 45 Genus CYTHEROPTERON Sars, 1866. 45 Genus ORTHONOTACYTHERE Alexander, 1933.
46 Subfamily CYTHERIDEINAE Sars, 1925. 47 Genus CLXTHROCYTHERIDEA Stephenson, 1936. 48 Genus HAPLOCYTHERIDEA Stephenson, 1936. 55 Haplocytheridea ? raybumensis Butler and Jones, Haplocytheridea Barectaensis (Brown), 1957.
57 page Haplocytheridea ? ulrichi (Berry), 1925. 58 Subfamily KRITHINAE Mandelstom, 1958. 59 Genus KRITHE Brady, Crosskey and Robertson, 1874-. 59 Krithe cushmant Alexander, 1929.
59 Subfamily PROGONOCYTHERINAE Sylvester-Bradley, 1948. 60 Genus PR0G0N0CYTHERE Sylvester-Bradley, 1948. 60 Subfamily BRACHYCYTHERINAE Puri, 1953. 6l Genus BRACHYCYTKERE Alexander, 1933.
64 Genus PTERGOCYTHERE Hill, 1954. 65 Subfamily TRACHYLEBERINAE Sylvester-Bradley, 1948. 66 Genus CYTHEREIS Jones, 1849. 66 Cythereis costatana Israelsky, 1929.
• 66 Cythereis communis Israelsky, 1929. 67 Cythereis hazardi Israelsky, 1929. 70 Genus VEENIA Butler and Jones, 1957. 72 Genus AMPHICYTHERURA Butler and Jones, 1957.
74 vi Page New Genus n. Cytherura ? aaratogana Israelsky,1929. 74 VIII LOCATION OF SAMPLES. 76 IX SELECTED BIBLIOGRAPHY.
85 ▼ii LIST OP TABLES Page I Percentages of Minerals Identified in each Thin Section;. 32 II Mean Grain Size, Standard Deviation from Mean, and Observed Range of Quartz Grains in Thin Sections where Quartz Exceeds Ten Percent. 33 III Trace Minerals and Matrix Description of all Thin Sections. 34 viii LIST OF FIGURES 1 Index Hap.
following page 2 2 Check List of Ostracod Species. following page 36 ix LIST OF PLATES I Outcrop Map of Ripley and Providence Formations of Western Georgia. in pocket II East-West Stratigraphic Section, Quitman County, Georgia to Peach County, Georgia (Shows stratigraphic position of ostracod samples and rock thin sections). in pocket III Ostracoda Species.
78 IV Ostracoda Species. 80 x ABSTRACT The Ripley formation (Gulfian) and its bounding formations in western Georgia were studied stratigraphically from the Chattahoochee River on the west to the Ocmulgee River on the east. Surface exposures were measured and described in detail and ostracod samples and rocks for thin sections were collected for study. An outcrop map of the Rip ley formation with the geographic location of the measured sections and a stratigraphic cross section with the position of all ostracod samples and rock thin sections are enclosed in the pocket.
The Ripley extends eastward into Georgia from Alabama and crops out from the Chattahoochee River to the Flint River where it is over lapped by the more northerly striking Providence sand. In western Georgia, the Ripley is composed of a nearshore marl that predominates updip and an offshore fine marine sand and clay that predominates down- dip. The offshore sand and clay extend eastward to the Flint River with very little facies change but thin from approximately 150 feet in the Chattahoochee River valley to approximately 50 feet in the area of the Flint River. East of the Flint River, the Providence sand overlaps the Ripley and lies unconformably upon the Cusseta sand.
In Twiggs County, evi dence suggests that the commercial kaolin is in beds of Cusseta and Providence ages where the Tertiary has overlapped both formations. A total of 37 species of Ostracoda have been found in the Ripley as a result of this investigation. Twenty-seven of these species have been reported previously. Of the remaining 10 species, four are de- scribed as new in this dissertation.
On the basis of the ostracoda, the Ripley of Georgia can be correlated with the Saratoga formation of Arkansas and the Peedee formation of North Carolina. xii INTRODUCTION This stratigraphic study of the Ripley formation developed from an attempt to solva the age and relationships of the pre-Jacksonian sedi ments east of the Ocmulgee River in central Georgia. These sediments have been mostly mapped as Tuscaloosa, but this writer agrees with Eargle (1955) that they represent the entire Upper Cretaceous Series of western Georgia. Because of the difficulty of finding traceable beds and the seemingly uniform lithology of the sediments east of the Ocmulgee River, it is extremely difficult to correlate with the forma tions west of the Ocmulgee.
Additional detailed work is needed on the mere easily mappable units of western Georgia before their eastern correlatives can be readily differentiated. Hoye Eargle (personal communication) kindly suggested at the beginning of this study that the Ripley formation might be a possible key to the problem. The Ripley formation and its bounding contacts were traced from the Chattahoochee River, where the Ripley can be readily identified both paleontologically and lithologically, to the east bank of the Flint River. In the absence of topographic map coverage in most of the area, county road maps were used as base maps and field data were located thereupon.
In addition, the altitudes of all measured sections were recorded with the aid of an altimeter, and were tied in to U. bench narks or other surveyed elevations. The field work for this study was dene between September 1956 and February 1957 and be tween June and September 1957* 1 Topography plays an important role in controlling the stratigraphic and paleont-ologic study of the Ripley of Georgia. The steep bluffs of the rejuvenated Chattahoochee River and adjacent higlands afford the only outcrops with fossil animal remains suitable for faunal study.
East of Buena Vista, Marion County, in an area of mere subdued relief, the sediments have been weathered. The weathering has masked the true lithology and dissolved the shells in the upper beds. Plate I shows the outcrop of the Ripley formation and the Provi dence sand and the location of the measured sections. The outcrop pattern west of the Flint River is after Eargle, 1955 and the outcrop pattern east of the Flint River is modified after Eargle, 1955 as a result of the field work for this dissertation.
Plate II shows the stratigraphic cross section and location and stratigraphic position of the ostracod samples and rock thin sections. Field St udy Fig. 1 STRATIGRAPHY GULFIAN General Features The Gulfian sediments of the Chattahoochee River valley of Georgia are divided into six formations: Providence sand Ripley formation Cusseta sand Blufftown formation Eutaw formation Tuscaloosa formation Langdon (1890, p. 605) in a general section along the Chattahoochee River divided the Cretaceous rocks of the region into Tuscaloosa, Eutaw, and Ripley, from oldest to youngest.
Subsequent investi gation resulted in the Blufftown, Cusseta, and Providence being elevated to formational rank. In 1939, the Georgia Division of Mines, Mining and Geology in co operation with the United States Geologic Survey published the Geologic Map of Georgia. The part of that map dealing with the Coastal Plain was based upon data from a manuscript prepared by C. Cooke's manuscript, "Geology of the Coastal Plain of Georgia," was not published 3 4 until 1943.
The Geologic Map of Georgia shows the Tuscaloosa cropping out from the Chattahoochee River on the west to the Savannah River on the east, the Eutaw and Blufftown formations extending from the Chatta hoochee to Marion County, the Cusseta sand to the Ocmulgee River, the Ripley formation to Macon County, and Providence sand to the Ocmulgee River. Eargle (1955) extended the Eutaw and Blufftown formations to the Flint River and the Ripley formation to the Ocmulgee River; mapped the Eutaw, Blufftown, and Cusseta as undifferentiated between the Flint and Ocmulgee Rivers; mapped all Cretaceous sediments in Georgia east of the Ocmulgee as, "Rocks of Tuscaloosa to Providence age, undifferentiated." In making these changes and extensions, Eargle emphasized the cyclic nature of deposition of the Cretaceous rocks. These cycles or units of these cycles helped him map contacts in the nonmarine facies of Georgia' east of the marine facies in the 8hattahoochee River valley. 5) described the Cretaceous rooks of the Coastal Plain as cyclic deposits most of which begin with coarse sand or gravel, progress upward through fine sand and clay and even chalky clay or chalk, and end with the beginning of another deposit of coarse sediment.
A formation may consist of a complete cycle or one or more units of a cycle. With the exception of the Tuscaloosa, which is nonmarine, all the Upper Cretaceous formations in the Chattahoochee River valley are fossiliferous in the upper beds. Toward the east, each of the formations, with the exception of the Ripley, grade laterally into nearly similar beds of. unfoasiliferous, coarse sand and clay.
The Ripley formation maintains the same general lithology eastward and fossil molds occur at the Flint River where the Ripley is overlapped by the coarse, crossbed ded sand of the Providence. RIPLEY FORMATION General Featvires The Ripley formation was first described by Hilgard (i860, p. 87) from localities near Ripley, Tippah County, Mississippi. Hilgard (i860) designated the Ripley as the sandy oarIs and limestones separating the underlying Cretaceous unit, the Rotten Limestone, from the overlying Northern Ligjaitic, which is Tertiary in age.
The Ripley formation crops out in a narrow belt from the Chatta hoochee River to the Flint River.