Correlation of the Cretaceous deposits of the eastern Gulf region and of the Carolinas.'^ 



[By L. W. Stephenson.] 



Kentucky and Illinoia. 



Eocene. 



o 



a- 

 P 



Absent. 



Ripley formation 

 (ahallow-water 

 phase). 



Tennessee. 



Eocene. 



Absent. 



>. o 



"Eg 

 K i 



Shallow-water 

 phase. 



Marine phase. 



Absent. 



Absent. 



Paleozoic. 



Selma chalk (impure 

 phase). 



Coffee sand member of 

 Eutaw formation. d 



Northern Mississippi 



Eocene. 



Absent. 



Ripley formation (ma- 

 rine phase). 



Sehna chalk. 



Western Alabama and 

 east-central Mississippi. 



Eocene. 



Absent. 



Selma chalk. 



Absent. 



Absent. 

 Paleozoic . 



3 



Coffee sand mem- 

 ber, d 



Tombigbee sand 

 member. 



Laminated sands 

 and clays. 



Tuscaloosa formation. 



Absent. 



Central Alabama. 



Eocene. 



Absent. 



Ripley formation. 



Eastern Alabama, including 

 immediate Chattahoochee 

 region in Georgia. 



Eocene. 



3 



Tombigbee sand 

 member. 



Laminated sands 

 and clays. 



Tuscaloosa formation. 



Absent. 

 Paleozoic. 



Absent. 



Paleozoic. 



Selma chalk. 



3 



Tombigbee sand 

 member. 



Laminated sands 

 and clays. 



Tuscaloosa formation. 



Ripley formation.* 



3 



Tombigbee sand mem- 

 ber.' 



Laminated and massive 

 sands, clays, and 

 marls. 



Absent. 





Paleozoic. 



Absent. 



Lower Cretaceous./ 



Crystalline rocks. 



Western Georgia east of imme- 

 diate Chattahoochee region. 



Central Georgia. 



Eocene. 



2 



Providence sand mem- 

 ber. 



Typical marine beds. 



Cusseta sand member. 



Eocene. 



Oh 



S 

 3 



Tombigbee sand mem- 

 ber. <= 



Providence sand mem- 

 ber. 



Cusseta sand member. 



Laminated and massive 

 sands, clays, and 

 marls. 



Absent. 



Lower Cretaceous./ 



Crystalline rocks. 



Absent. 



Lower Cretaceous./ 



Crystalline rocks. 



South Carolina. 



Eocene. 



Absent. 



Peedee sand. 



North Carolina. 



Eocene. 



Absent. 



Peedee sand. 





P5 



Typical irregularly bed- 

 ded sands and clays. 



Middendorf arkose 

 member. 



-le- 



Absent. 



Lower Cretaceous. 

 Crystalline rocks. 



Black Creek formation. 



^?«-. 



Absent. 



Patuxent formation. » 



Crystalline rocks. 



a For extension of the correlation northward, see p. 612. 



t> A series of nonchalky equivalents of the Selma chalk referred by Langdon to the Ripley. 



« Included by Langdon in his Ripley group. 



<i Correlated by Safford and subsequent investigators with the Eutaw formation, but now considered to represent only the upper part of the Eutaw. 



« The stratigraphic position of the base of the Black Creek formation with reference to the eastern Gulf section has not been established with accuracy. 



....„>-.„ Unconformity Line of separation between members of a formation. 



48011°— 12. (To face page 654.) 



/ Correlated by Langdon and others with the Tuscaloosa formation (Upper Cretaceous) of central and western Alabama, but on the evidence of 

 fossil plants now referred to the Lower Cretaceous. It has not been proved that this division is synchronous with the Patuxent ("Cape Fear") 

 formation of the Carolinas, as indicated in the table. -. r / 



g Correlated with the Patuxent formation on physical evidence only. Since the extension of this name to include the "Cape Fear" formation 

 of North Carolina some doubt has arisen as to the correctness of the correlation. 



