Please do not destroy or throw away this publication. If you have no further use for it, write to the Geological Survey at Washington and ask for a frank to return it UNITED STATES DEPARTMENT OF THE INTERIOR Harold L. Ickes, Secretary GEOLOGICAL SURVEY W. C. Mendenhall, Director Bulletin 867 GEOLOGY OF THE COASTAL PLAIN OF SOUTH CAROLINA BY C. WYTHE COOKE UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1936 For sale by the Superintendent of Documents, Washington, D. C. ------ Price 60 cents CONTENTS ,Page Abstract.___-_-_----_--------------_---_------------_------_-.--. 1 Physical geography _______---_-___-_-_-_-_-__-_____-_--_____-__ 2 Geographic provinces.._-----------_----_---_-_.__.--_-_..._.__ 2 Geographic divisions of the Coastal Plain of South Carolina___.____ 3 Coastal terraces_________________________________________ 4 Pamlico terrace._____._-_-____.-___..___ ______________ 6 Talbot terrace_._---_._-..___.. ..___.....___.__._._ 7 Penholoway terrace.___-___-___-_-_____-__--__--___-__ 8 Wicomico terrace._____--__-_-_---__---_----_-__--_-__ 8 Sunderland terrace.._._-.-__-._----.___-.--____.-____. 8 Coharie terrace___------__--___---_.--_-_-----------._ 9 Brandy wine terrace ____-_-_--___--__---_--_--_-_--_--- 9 Aiken Plateau._----_-----_-_--____-__-_--------------_--_ 9 Richland red hills.-_______-__-__-_.----.--_---___._._._--_ 10 High Hills of Santee---------___......_....___...__.._. 10 Congaree sand hills__----_---.____--_-__---.----.-------_ 11 Drainage__ ____---------_-_-.--__-...---__--_-_-__-__.-_._.. 11 Principal streams.____----_-_.-_-_.-------_-_-__-._--_--_. 11 Development of the drainage.-__-...-_-.__-__._.__-.__-___. 13 Stratigraphy__ _ _________________________________________________ 14 Formations included____-__--_.-__.._.----__-_____--_-.__._-. 14 Upper Cretaceous series_.----____.___.-_-___._-_-_-_-_.--_-._ 15 General features.___--__-_______-__---_--__-__-_--_----._- 15 Tuscaloosa formation.--.-.---..-.....-------------------. 17 Black Creek formation__._.--_-...---__.____-__--._--._-- 25 Peedee formation..._.__--._.______--___--___-_____._-____ 32 Eocene series._____--_-_____---_--_---_------___----_--------- 39 Correlation_ _-_-_-__--_______--__-----___---.-.-_------- 39 Black Mingo formation._.__________-____-_-_____.-..._____ 41 McBean formation._________-______-____-________-_-_-_--_ 55 Deposits of Jackson age...._-__-__-_---___----.___---_----- 72 General character.._--____-----------_--__----___----- 72 History of the names "Santee" and "Cooper".__._____-_- 73 Santee limestone._-__---_____._--____----_-_._..___--- 75 Cooper marl._____-_--__-__-___-__------___---_-___--- 82 Barn well sand ___------_--__-_------_--_-_--__-____-_- 89 Oligocene series.____-_-__-.---_---_-_---_--_--_-__---____----- 96 Flint River formation._-____-_--_-----_--_______-__-_-_-- 98 Miocene series.____--_____-_--______.__-----_--_-__-----__--_- 99 General features.____.-_--_____-__----___-----_--_----.--- 99 Hawthorn formation.___._._______---__-._____.__-_.._--- 101 Raysor marl_-__-___---__._____-_-_------_-____._.___--- 115 Duplin marl_-_-----------------_-_----------------------- 117 Pliocene series___-_---_-----_---_-____---_--------__--___----- 123 General features.----------.------------ _-_-___.--.----- 123 Waccamaw formation____.--_.______ .__.-___._-__.__-_--- 124 in IV CONTENTS Stratigraphy Continued. page Pleistocene series ____-_- _____ ____________ ____ 130 Fluctuations of sea level_____ ____________________ ____ 130 Marine formations. ...._-_-__________________---.___-__-___ 130 Brandywine formation_______________________________ 131 Coharie formation_______________________-_____________ 132 Sunderland formation _____________________________ 136 Wicomico formation_-_________________________________ 143 Penholoway formation_________________________________ 147 Talbot formation_________________..______ __ _ 148 Pamlico formation.________ _______ 149 Geologic history.____-----_---------- -----_______---_-_-_--_-___ 154 Structure._____----__----_---------_--------___---_---_---_----__ 158 Mineral resources.. - ----_--___.---____ __-__-_ 159 Metals..__-___----_--------_----------_-__----__----------- 159 Nonmetals ______----------------__------_----__---_ -------_ 159 Phosphate rock_____--_--__________-__----___--_-_ ______ 159 Limestone and calcareous marl._-_--_________--___-----_-__ 159 Clay...- --- ----------- -_----- ---- - 160 Sand and gravel.....----- ____-_-____- .-._ 161 Mineral fuels.--------------___-_______ _________________ 161 Ground water.___-----_-------__----_--_---_---_--____-______ 161 Sources._--_.-----------------_-----------_.___.-____ 162 Description by counties _____________________________ 164 Aiken County_____---_________________.______________ 164 Allendale County.____________________________ 165 Bamberg County____._________________________________ 166 Barnwell County -____-____._______________ 166 Beaufort County.. .....__________________ 167 Berkeley County --_______.___._-_______.___ 168 Calhoun County.......__._.__..._________ 169 Charleston County__________________________;______.__ 170 Chesterfield County...__....________________ 171 Clarendon County________________________.___________ 171 Colleton County-.--..._______._____________ 172 Darlington County __________________________________ 173 Dillon County____________________________________ 175 Dorchester County ______________________ ' 176 Florence County.______________________________^______ 177 Georgetown County______________________.____________ 179 Hampton County.....______________________ 180 Horry County..._ ______________________ 181 Jasper County __-... _________________. 182 Kershaw County__._____________________ 182 Lee County____------______.___._.__. __ ._ 183 Lexington County___________________________________ 183 Marion County_______________________________________ 184 Marlboro County.____________________________________ 184 Orangeburg County.__________________________________ 185 Richland County__________-_-_--__-_ .___-._ 186 Sumter County....--.....-...------------------------ 186 Williamsburg County___.__-__-__ ___.-...--_______ 187 Index________________...______________--. _ 189 ILLUSTRATIONS Page PLATE 1. Map showing the distribution of the Pleistocene terraces and the original extent of the Pleistocene formations in South Carolina________-_--------_-___---___..__---__-__ In pocket 2. Geologic map of the Coastal Plain of South Carolina...... In pocket 3. A, A sand dune on Folly Island; B, Stumps on the beach at Folly Island; C, Encroachment of the sea on Folly Island-.. 2 4. Land and sea in Pamlico time.______-_-_---____--_____--_ 10 5. Land and sea in Talbot time.____________________________ 10 6. Land and sea in Penholoway time._____--_______-______--_ 10 7. Land and sea in Wicomico time._____-_-----___---______-_ 10 8. Land and sea in Sunderland time..____-_--______-__-_____ 10 9. Land and sea in Coharie time.___________________________ 10 10. Land and sea in Brandy wine time. _ _______________________ 10 11. A, Erosion in the Aiken Plateau exposing the Upper Cretaceous Tuscaloosa formation on upper Aiken-Graniteville road 4 miles west of Aiken; B, Tuscaloosa formation 2 miles northeast of Middendorf..___.___-_----__.___._________ 18 12. A, Tuscaloosa formation 1 mile north of Langley; B, Mars Bluff, Pee Dee River_._____-..____..________ 19 13. A, Tuscaloosa-Black Creek (?) contact 1 mile west of Wedge- field; B, Dewitts Bluff, Pee Dee River. ____.._____ 26 14. A, Contact between the Black Mingo formation and the McBean formation near Bates Mill, Calhoun County; B, Marl pit at Lambs.-..-__------__--------_--_-____--_ 27 15. A, Barn well sand in railroad cut at Aiken; B, Sandstone of Barnwell age on the Dibble farm 5% miles southeast of Aiken. __..______.._..___.____________. 90 16. A, Barnwell sand near Bethel Church, Lexington County; B, Unconformity between the Hawthorn formation (f Marks Head marl) and the Duplin marl above Enochs wood landing, Savannah River, 67% miles above Savannah.._ 91 17. Mosaic of aerial photographs of part of Horry County between Waccamaw River and the ocean__________.____.____..__ 154 18. Map showing the approximate original distribution of phosphate deposits in South Carolina____________-________________ 154 FIGURE 1. Geographic divisions of the Coastal Plain of South Carolina.- 4 2. Ideal profile across the coastal terraces ______________ _ __. 6 GEOLOGY OF THE COASTAL PLAIN OF SOUTH CAROLINA By C. WYTHE COOKE ABSTRACT The Coastal Plain of South Carolina extends from the Atlantic Ocean inland a distance ranging from 120 to 150 miles to the Fall Line, where it adjoins the Piedmont province. It includes an area of more than 20,000 square miles, or nearly two-thirds of the State, whose total area is 30,981 square miles, of which 494 square miles is water. The geographic divisions of the Coastal Plain are the marine coastal terraces, or "low country", which stand less than 270 feet above sea level, and the Aiken Plateau, the High Hills of Santee, the Richland red hills, and the Congaree sand hills. Few places in the Coastal Plain are as high as 600 feet above sea level. The coastal terraces together have an area more than twice as great as all the rest of the Coastal Plain. The landward limit of each terrace is defined by the level shore line at which the sea" and its estuaries stood when the terrace was under water. The seaward limit is the shore line of the next lower terrace. The names of the terraces and the approximate present altitude of the shore line of each