386 BRUCE WADE 



Cockerell/ which Professor Cockerell says is the only known speci- 

 men of an American amber insect. 



Toward the north the Eutaw formation becomes much thinner 

 until in the vicinity of Dulac in the northern part of Henry County 

 near the Kentucky line this formation is only about twenty feet 

 in thickness. At Riverview, a locality about five miles south of 

 Paducah on the Tennessee River in Kentucky, an exposure of 1 5 feet 

 of typically laminated Eutaw sands and clays may be observed. 

 In the central part of Decatur County, Tennessee, in the vicinity 

 of Parsons and Decaturville, the basal part of the Eutaw contains 

 irregular lenses of fine chert and quartz gravels sometimes several 

 feet in thickness. Some other vicinities in Tennessee where the 

 Eutaw may be studied are Camden, Holladay, Darden, Scotts 

 Hill, Crumps Landing, Pittsburg Landing, Red Sulphur Springs, 

 etc. The general distribution of the formation is given on the 

 accompanying map. 



THE SELMA FORMATION 



The name Selma was used in Tennessee as a formational name 

 in 1906 by Glenn,^ who pointed out that the original term, Selma 

 chalk, was applied very aptly in Mississippi and Alabama but was 

 inappropriate in Tennessee. The Selma formation, as represented 

 in the northern gulf embayment regions, consists of fossiliferous 

 chalky clays and argillaceous, micaceous sands laid down during 

 the time when the Upper Cretaceous sea was at its maximum stage 

 of transgression. This stage may be traced across the state of 

 Tennessee by its lithology and fauna, separating the underlying 

 Eutaw sands and the overlying Ripley sands. There are no known 

 unconformities in this Eutaw-Selma-Ripley series, which evidently 

 represents a single cycle of transgression and regression of the 

 Upper Cretaceous sea in Turonian and Senonian time. This 

 cycle took place very slowly and probably extended over a long 

 period of time. The cross-bedded largely non-marine sands and 

 clays of the Eutaw represent the advancing stage of this sea. The 

 Selma chalky sediments represent this sea at its maximum expanse 



I T. D. A. Cockerell, Proc. U.S. Nat. Mus., Vol. II (1916), p. 99, Fig. 6. 

 = L. C. Glenn, U.S.G.S. Water Supply Paper 164 (1906), p. 26. 



