450 W. J. McGee — Three Formations of 



Mather recognized the formation on Long Island in 1843, 

 enumerated its fossils, referred it to the " Long Island divis- 

 ion " of the " upper secondary system," * attributed it to a 

 marine current flowing northward " along the eastern coast," 

 and inferred from the paucity of organic remains and the 

 presence of ice-borne blocks that the temperature was low 

 during its deposition. 



The formation attracted Ly ell's attention during his two 

 visits to this country : During the earlier he referred to the 

 " post-Pliocene " " the marine shells " of eastern Georgia and 

 South Carolina, which " differ in no way from those of the ad- 

 joining sea," " contained in deposits of clay and sand " over- 

 lain in some places by dark colored clays yielding "remains 

 of quadrupeds of extinct species ;" and concluded that at the 

 time of deposition the land stood lower than now, while 

 the temperature of atmosphere and ocean were little different 

 from to-day. f During the later he discriminated the "low 

 region bordering the Atlantic " from southern Georgia to the 

 Neuse River in North Carolina, and made up of stratified 

 sands and clays yielding recent marine shells from the terraces 

 of Eocene deposits by which it is overlooked — the low plain 

 rising but ten to forty feet above tide arid extending only 

 twenty miles inland.;}: 



A few years later Tuomey described the same deposit in 

 South Carolina as "sand, clay and mud, containing fossils, 

 some sixty feet thick," rising eight feet above tide and ex- 

 tending only eight or nine miles inland,§ enumerated its fos- 

 sils — which are all marine and nearly all recent and local, | — 

 and referred it to the post-Pliocene. 



The observations of Lyell and Tuomey are significant in 

 that the}^ indicate narrowing and lowering of the formation 

 southward. 



In 1852 Desor reviewed the paleontology of the formation 

 as developed from South Carolina to Sancoty Head and Point 

 Shirley, noted that the fossils are " nearly all referable to liv- 

 ing- species " and that the deposit occupies only a narrow zone 

 rising eighteen feet above tide in the south but widening 

 greatly and reaching an altitude of 100 feet northward,!" and 

 inferred not only that it is marine, but that the climate was 

 warmer than now when it was deposited. He classed the 

 formation as post-Pliocene, and correlated it with the " Lauren- 

 tian " of Canada and New England. 



* Geology of K Y., Part I, 1843, 246, 261-8, 274-5. 

 f Quart. Jour. Geo!. Soc vol. ii, 1846, 405-6. 



% Second Visit to the U. 3., N. Y. 1855, vol. i, 256-61 ; vol. ii, 197. 

 § Geology of South Caroliua, 1848, 186, 188, 212. 

 || Ibid., 203-5. 



IThis Journal, II, 1852, 50-3 ; c. f., Proe. Boston Soc. Nat. Hist., Ill, 1851, 

 79; Mem. Boston Soc. Nat. Hist., 1866-9, 252. 



