HISTORICAL GEOLOGY 



77 



access to the horizontal and highly f ossilif erous strata of 

 the coastal plain. The first one to attract attention was 

 Thomas Say, after him came John Finch, followed by 

 Lardner Vanuxem, Isaac Lea, Samuel G. Morton, and 

 T. A. Conrad. These men not only worked out the 

 succession of the Cenozoic and the upper part of the 

 Mesozoic, but blazed the way among the Paleozoic strata 

 as well. 



Thomas Say (1787-1834), in 1819, was the first Ameri- 

 can to point out the chronogenetic value of fossils in his 

 article, Observations on some Species of Zoophytes, 

 Shells, etc., principally Fossil (1, 381). He correctly 

 states that the progress of geology ''must be in part 

 founded on a knowledge of the different genera and 

 species of reliquiae, which the various accessible strata of 

 the earth present. ' ' Say fully realizes the difficulties in 

 the study of fossils, because of their fragmental charac- 

 ter and changed nature, and that their correct interpre- 

 tation requires a knowledge of similar living organisms. 



The application of what Say pointed out came first in 

 John Finch's Geological Essay on the Tertiary Forma- 

 tions in America (7, 31, 1824). Even though the paper 

 is still laboring under the mineral system and does not 

 discern the presence of Cretaceous strata among his Ter- 

 tiary formations, yet Finch also sees that "fossils con- 

 stitute the medals of the ancient world, by which to ascer- 

 tain the various periods." 



Finch now objects to the wide misuse in America of 

 the term alluvial and holds that it is applied to what is 

 elsewhere known as Tertiary. He says : 



"Geology will achieve a triumph in America, when the term 

 alluvial shall be banished from her Geological Essays, or con- 

 fined to its legitimate domain, and then her tertiary formations 

 will be seen to coincide with those of Europe, and the formations 

 of London, Paris, and the Isle of Wight, will find kindred asso- 

 ciations in Virginia, the Carolinas, Georgias, the Floridas, and 

 Louisiana. ' ' 



The formations as he has them from the bottom 

 upwards are: (1) Ferruginous sand, (2) Plastic clay, 

 (3) Calcaire Silicieuse of the Paris- Basin, (4) London 

 Clay, (5) Calcaire Ostree, (6) Upper marine formation, 

 (7) Diluvial. 



