in Florida in Association with Extinct Vertebrates. 3 



beaches and dunes, at the time the sea withdrew from the land ; 

 and are thus contemporaneous in age or nearly so with the 

 marine shell marls. However, in ponds, streams and lakes, 

 fresh-water marls, sand and muck deposits accumulated which 

 rest upon and hence are of somewhat later age than the marine 

 marls, and it is in deposits of this kind chiefly, as would be 

 expected, that the land and fresh-water fossils are preserved. 

 A more detailed account of a section through a stream bed at 

 Vero will be given in connection with the description of the 

 fossil human remains. 



Geologic History of the Florida East Coast. 



The geologic history of the Florida East Coast will be con- 

 sidered in this paper only in so far as it affects the locality 

 under discussion. It is known that the early Pleistocene 

 included a period of great submergence during which the exten- 

 sive marine marls and limestones of eastern and southern 

 Florida were deposited. Following the accumulation of these 

 early Pleistocene formations the peninsula was lifted in rela- 

 tion to the strand-line to a level somewhat above its present 

 elevation. This period of probably slight emergence was fol- 

 lowed by a depression, proof of which is derived from many 

 sources and is conclusive. Shaler long ago noted the fact that 

 the important harbors of Florida are flooded river valleys. 2 

 Vaughan likewise has called attention to the submerged chan- 

 nels of both the Atlantic and the Gulf coasts which, together 

 with other evidence, lead him to conclude that both the mainland 

 and the Keys of the Florida East Coast stood at the time of 

 maximum Pleistocene emergence as much as 30 feet above the 

 present strand line. 3 The existence of a Pleistocene cypress 

 swamp in Hillsboro Bay, 20 feet below the present sea level, 

 'and of a peat bed at the same depth near the Florida Keys on 

 the Atlantic Coast, has been noted by the writer. Additional 

 evidence of changes of level may be adduced from physio- 

 graphic features in the interior of the State, particularly from 

 the lakes of the "Lake Region" of Florida, the basins of 

 which probably originated through sinkhole formation at a 

 time when the land area stood higher than at present. 4 The 



2 The Geological History of Harbors, U. S. Geol. Surv., 13th Ann. Rept., 

 pt. 2, pp. 190-192, 1893. 



3 Sketch of the Geologic History of the Florida Coral Reef Tract and 

 Comparisons with Other Coral Reef Areas, Washington Acad. Sciences, 

 vol. iv, p. 30, 1914. 



4 Florida State Geol. Surv., Seventh Annual Report, p. 56, 1915; ibid., 

 Sixth Annual Report, p. 155, 1914. 



