PALEOCENE SERIES 



The Paleocene Series represents one of the best known stratigraphic units, having been identified in 

 more than 70 wells that are fairly well distributed over the Coastal Plain of Georgia. In southwest Georgia 

 and southeastern Alabama, it is best developed and thickest of any place in the entire Gulf Coast. Beds 

 of Paleocene age underlie the lower Eocene and overlie the Upper Cretaceous. Except for extreme south- 

 eastern Georgia, the Paleocene uniformly consists of limestones with some overlying clays and indurated 

 sands, all of which are correlated with the Clayton Formation of Alabama. In southeastern Georgia, 

 in eastern Echols and in Clinch, Camden, and Glynn Counties, the Paleocene is considered equivalent to 

 the Cedar Keys Limestone of Florida. The oldest Paleocene, which occurs in extreme south Georgia, 

 is composed of a series of elastics that occupies a position intermediate between the base of the Clayton 

 (above) and the Upper Cretaceous (below), and is correlated with the Tamesi* of Mexico. The subsur- 

 face areal extent of the Paleocene deposits in Georgia (see fig. 12) is approximately the same as that for 

 the previously discussed lower Eocene. Also, the Paleocene like the lower Eocene, is overlapped in eastern 

 Macon County by geologically younger sediments. In its outcrop area, the Paleocene consists of dark-gray 

 to black to dark-chocolate-brown, blocky to laminated, silty, glauconitic, micaceous, fossiliferous clay 

 and marl that overlie light-gray to cream, somewhat dense, crystalline, sandy, coarsely glauconitic, 

 pyritiferous, fossiliferous limestone. In the Chattahoochee Valley at Fort Gaines, the Clayton Limestone 

 consists in the upper part of cream, somewhat chalky, earthy, porous, fossiliferous limestone that changes 

 at depth to more massive, crystalline, sandy limestone. Downdip the overlying brown to black clay of 

 latest Paleocene age gradually merges into light-gray, fine-grained, finely glauconitic, micaceous, 

 fossiliferous, indurated sandy limestone or indurated sand. In extreme southeastern Georgia the Paleocene 

 consists of white to cream, somewhat calcitized, gypsiferous, fossiliferous limestones that are lithologi- 

 cally similar to the Cedar Keys Limestone of northeastern Florida. Between the base of the Clayton 

 Limestone proper and the top of the underlying Upper Cretaceous, the earliest Paleocene, or Tamesi? 

 is present in extreme south Georgia and in the subsurface of northeastern Chatham County. In these areas 

 it consists of dark-brown, laminated, silty, glauconitic, finely micaceous, abundantly fossiliferous marl. 

 As noted above these fossiliferous marls are, in this report, included in the Clayton Formation but are 

 Tamesi'' (earliest Paleocene) in age. The Paleocene increases in thickness down the dip from a few feet 

 along its northern boundary to over 600 feet in southern Georgia (see fig. 13). In the Chattahoochee Valley, 

 MacNeil (1944, p. 22) reported 130 feet of outcropping limestone belonging to this stratigraphic unit. On 

 the basis of available evidence the Paleocene apparently did not undergo any particular localized thickening. 

 As with the Lower Eocene, possible depocenters of the Paleocene may exist off the coast of western 

 Florida as well as off the coast of Bryan or Liberty Counties, Ga. 



Some of the articles dealing with the Paleocene Foraminifera include papers by Plummer (1926), Cush- 

 man (1926 and 1951), White (1928 and 1929), Muir (1936), Cole and Herrick (1953), and Shifflett (1948). 

 The Paleocene in Georgia contains an abundant and varied foraminiferal fauna. Some of the commonly 

 occurring guide fossils that are found either at or close to the top of this unit include Operculinoides 

 catenula (Cushman and Jarvis), Pseudophragmina ( Athecocyclina ) stepnensom (Vaughan), Robulus Midway- 

 ensis (Plummer), Discorbis midwayensis Cushman var. trinitatensis Cushman and Renz, Eponides lotus 

 (Schwager), Parrella expansa Toulmin, and Anomc.Iina midwayensis (Plummer). The Foraminifera of the 

 Paleocene illustrate probably better than any other single fauna in Georgia a close faunal relationship 

 to the Paleocene of the West Indies and Mexico, a fact that can be gleaned from the faunal lists in table 



*As pointed out by P. L. and E. R. Applin (1944, p. 1703, 1705) the Tamesi"(Velasco) of Mexico was, 

 for a long time considered to be latest Cretaceous in age but is now known to represent earliest Paleocene. 



36 



