454 W. J. McGee — Three Formations of 



the unconformable superposition of the former upon it, — enu- 

 merates the fossils from the older deposits, and on their testi- 

 mony refers it to the post-Pliocene and correlates it with the 

 fossiliferous beds of Sancoty Head, and concludes that it was 

 "formed by swift currents which carried along fine and coarse 

 deposits together."* 



In 1884 Britton pointed out (1) that the Yellow Gravel of 

 Staten Island and adjacent New Jersey is " a water deposit 

 known to underlie the glacial drift," masses of it being " im- 

 bedded in the moraine," and (2) that it reaches altitudes of 200 

 feet,f while the terraces connected with the terminal moraine 

 rise only 25 or 30 feet above tide.;}:. He subsequently followed 

 Cook in designating the formation " Pre-Glacial Drift," noted 

 that it "is distributed along the Atlantic Border, from the 

 coasts of the Southern States northward to the moraine, which 

 it underlies unconformably," mentioned its unconformity to 

 the Miocene, enumerated the fossil plants (mostly recent and 

 local) obtained from it at Bridgeton, N. J., and inferred (1) 

 that it is "later Pliocene or Pleistocene" in age, and (2) that 

 " a considerable amount if not the greater part" of the deposits 

 " may well have come from the erosion of the Cretaceous 

 gravel beds" along the Piedmont margin§ — his enumeration 

 and interpretation of the local phenomena being alike emi- 

 nently satisfactory. 



Reviewing the observations of these geologists, it appears 

 (1) that the Rogers brothers, Booth, Conrad, Mather, Lyell, 

 Tuomey, and Desor found a series of stratified sands and clays, 

 containing recent marine shells, rising and expanding from a 

 few feet above tide and a few miles in width in South Caro- 

 lina, to over 100 feet in altitude, and scores of miles in width 

 in the northern Coastal plain, the fauna being closely related 

 to or identical with that of Gardiner's Island, Sancoty Head, 

 Shirley Point, and other obscure infra-moraine deposits along 

 the New England coast; (2) that these deposits have been 

 shown by "W. B. Rogers, Tyson, Kerr and Chester, on the evi- 

 dence of stratigraphic continuity, unity of structure, and iden- 

 tity of terraces, to extend to the inland margin of the Coastal 

 plain ; (3) that Chester has identified the phenomena and in 

 some cases the localities described by Tyson and Booth, and 

 shown that the brick clays and red gravels of the Delaware 

 fall-line are stratigraphically continuous and homogenetic with 

 the fossiliferous marine deposits recognized along the coast by 

 the older geologists ; (4) that Lewis has established the identity 

 (in part) of the Philadelphia deposits with the gravels shown 



* Annals N. T. Acad. Sci.. iii, 18S6, 354-8. 



f Proc. Nat. Sci. Assn. of Staten Island, Nov. 8, 1884. 



% Ibid., April 10, 1886. 



§ Trans. N. Y. Acad. Sci., iv, 1884-5 (1887), 26-33. 



