Tertiary Stratigraphy of South Carolina GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-B Tertiary Stratigraphy of South Carolina By C. WYTHE COOKE and F. STEARNS MAcNEIL SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952, PAGES 19-29 GEOLOGICAL SURVEY PROFESSIONAL PAPER 243-B A revised classification of Tertiary formations of the Coastal Plain, based mainly on new stratigraphic and paleontologic information UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1952 UNITED STATES DEPARTMENT OF THE INTERIOR Oscar L. Chapman, Secretary v GEOLOGICAL SURVEY W. E. Wrather, Director For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price. 15 cents (paper cover) CONTENTS Page Page Abstract- ______ _____.. _________ 19 Paleocene (?) and Eocene series- -Continued Introduction ________._!________ 19 Deposits of Jackson age. 26 Paleocene (?) and Eocene series-. 19 Barnwell formation. _ _. 26 Deposits of Wilcox age _____ 20 Oligocene series______________ 27 Deposits of Claiborne age___ 21 Cooper marl._________ 27 Congaree formation____ 21 Miocene series_______________ 28 Warley Hill marl ______ 23 Hawthorn formation. _. 28 Me Bean formation___ 23 Santee limestone_____ 24 References. ____________l_-___. 28 Castle Hayne limestone- 25 ILLUSTRATION Figure 2. Correlation of Tertiary formations of South Carolina. 20 in 99308T—52 TERTIARY STRATIGRAPHY OF SOUTH CAROLINA By C. WYTHE COOKE AND F. STEARNS ABSTRACT bridges have been built, and places formerly inacces­ The following changes in the current classification of the sible are now within easy reach. The spoil bank of Tertiary formations of South Carolina are proposed: The Black the Santee-Cooper Diversion Canal, cut about 1940, Mingo formation, mainly of Wilcox age, may include some Paleo- has brought to the surface an abundance of fossils of cene deposits. The McBean formation, heretofore including all the deposits of known Claiborne age in South Carolina, is re­ the Santee limestone, including species that had not stricted to the Ostrea sellaeformis zone, of late middle Claiborne been collected since the 1830's, wheji the original Santee age, and the names Congaree formation (equivalent to the Canal was dug. The associated fauna of the more TaJlahatta formation) and Warley Hill marl (equivalent to the characteristic of these species is now known for the first Winona formation) are revived for deposits of early Claiborne time. New pits sunk in the flat, featureless Pleisto­ and early middle Claiborne age. A large part of the deposits mapped as Barnwell formation (of Jackson age) proves to be cene plain yield unsuspected evidence as to the age of Congaree. The Santee limestone, heretofore supposed to be of the underlying limestones. early Jackson age, represents the Ostrea seMaeformis zone and Since 1935 MacNeil has been making stratigraphic seems to be an offshore facies of the restricted McBean forma­ studies on the Tertiary formations of Mississippi, Ala­ tion. The Castle Hayne limestone, heretofore known only in bama, Georgia, and Florida. These have resulted in North Carolina and referred to the middle Jackson, occurs under cover in South Carolina. Its fauna shows it to be equivalent more accurate information as to the geologic ranges of to the Gosport sand, of late Claiborne age. The Cooper marl, fossils, and familiarity with the stratigraphy of the currently referred to the late Eocene (Jackson), is reassigned formations containing them. Using this information to the early Oligocene? on the basis of its mollusks, foramini- he was able, during a three-week reconnaissance during fers, and cetaceans. A gravelly facies of the Miocene Hawthorn 1950, presumably preliminary to the preparation of a formation similar to that in Georgia is recognized for the first time in South Carolina, where the formation had previously new geologic map of the Tertiary formations of South been recognized only by its offshore facies. Carolina, to make closer correlations with the type sec­ tions in Mississippi and Alabama than had been possible INTRODUCTION in 1936. The writers made two short trips to South The Coastal Plain of South Carolina has received Carolina together in May and June of 1951. somewhat less attention than that of the neighboring PALEOCENE (?) AND EOCENE SERIES State of Georgia, and in comparison with the Coastal Plain of the Gulf States, which in recent years have The name Paleocene series was not adopted by the been the center of extensive oil exploration, little is U. S. Geological Survey until after the publication of known. Since the days of Lyell only three general ac­ Cooke's 1936 paper. The deposits in the southeastern counts of the stratigraphy of the Coastal Plain of South States now referred to the Paleocene form the Midway Carolina have been published, one by Tuomey in 1848, group, which had previously been treated as the oldest one by Sloan in 1908, and the most recent by Cooke in division of the Eocene series. Since the removal of the 1936 as Bulletin 867 of the United States Geological Midway group to the Paleocene, the Eocene series in the Survey. Southern States has included only three groups—the The present paper presents a revised classification of Wilcox, Claiborne, and Jackson, represented in South the Tertiary formations of South Carolina, and indi­ Carolina, though the group names have not been ap­ cates some of the changes necessary on the existing plied there. In addition there is somewhat meager geologic map of the State. However, the greater part evidence to indicate that the lowest of the units here of the information on which this revision is based comes recognized may include beds of both Paleocene and from entirely new exposures and new collections of early Eocene (Wilcox) age. fossils, and even the interpretation of the molluscan The only known representative of the Wilcox group faunas is based on revised knowledge of the range of in South Carolina is the Black Mingo formation. There species. is some evidence that the beds now included in the Black Travel in the Coastal Plain is now much easier and Mingo may be in part of Paleocene age, but the evidence faster than it was before 1936. Many new roads and is inconclusive, The Claiborne group is more fully 19 20 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1952 South North Mississippi Alabama Carolina Carolina Ocala Yazoo clay ^ . Cocoa sand ^ limestone \ member \ Barnwell ^" S Sand, silt, formation Moodys Branch formation ^-^X~^--~^X~^'''"^-'-^^-N-' Cockfield formation Gosport sand Castle Hayne limestone .^x^..XX^x-^^^^X-^x-VtaX^x-.*^.„ •N^-V—• Cook Mountain formation Ostrea sellaeformis zone McBean •~^s~*~<~***r^' Sparta sand (Present) (Koscinsko sand) Zilpha clay (Absent?) Warley Hill Ostrea smithvillensis zone marl Winona formation Ostrea lisbonensis zone Congaree Tall aha tt a formation formation Hatchetigbee formation Bashi marl member Wilcox formation Tuscahoma sand Nanafalia formation Black Mingo formation Fearn Springs sand member 1 Nonfossiliferous, nonglauconitic limestone at Cave Hall may be of this age. 2 May include some Paleocene. FIGURE 2.—Correlation of Tertiary formations of South Carolina. represented. As here revised it includes the Congaree well. Residues of limestone of Jackson age certainly formation of early Claiborne age, the Warley Hill marl are present elsewhere in Barnwell County beneath the (both included in the McBean in Bulletin 867," Cooke, Hawthorne cover, and there is no reason why the name 1936), the restricted McBean formation and its offshore Barnwell cannot be applied to the unleached Jackson equivalent the Santee limestone of middle Claiborne beds farther down the dip even though its type area age, and the Castle Hayne limestone, as here restricted, falls entirely within the area of solution. of late Claiborne age. The Jackson group is repre­ The relationships of the Eocene formations in the sented by sandy limestone and perhaps down dip by a Carolinas to one another and to the generalized stand­ less sandy facies. At the present, outcrop beds of ard section in Georgia and Alabama are indicated in Jackson age are almost completely reduced to oxidized the correlation chart (fig. 2). sandy residues. The name Barnwell formation was ap­ plied to leached residues of the sandy limestone and no DEPOSITS OF WILCOX AGE type locality was ever designated. It now appears that The Black Mingo formation was referred to as being actually the railroad cut at Barnwell was made in a of Wilcox age (Cooke, 1936) primarily because of the part of the Miocene Hawthorne formation, although presence of Ostrea arrosis Aldrich. Although this many geologists must have regarded it as typical Barn- oyster was stated by Aldrich to be from the Nanafalia TERTIARY STRATIGRAPHY OF SOUTH CAROLINA 21 formation, and has since been found to be restricted Sloan's names (1907,1908), Rhems shale or Lang Syne to it, in the correlation table (p. 40) the Black Mingo shale, may be available. was placed opposite the Tuscahoma sand of Alabama DEPOSITS OF CLAIBOBNE AGE because of the occurrence in both of Twrritella mortoni Conrad, a species now known to be abundant in both All the then-known deposits of Claiborne age were the Nanaf alia and the Tuscahoma. Mapped with this included by Cooke (1936) in one formation, the Mc- oyster-bearing bed were underlying siliceous clay- Bean. This was the original usage in Georgia, where, shales and an overlying massive red sand now known according to Veatch and Stephenson (1911, p. 237), the to be of early Claiborne age. A revised map would