56 TRANSACTIONS OF THE WAGNER FREE 



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the Tertiary deposits accompanying my " Contributions to the Tertiary 

 Geology and Paleontology of the United States" (1884). Our recent 

 explorations, however, prove the utter erroneousness of the view here 

 entertained, and indicate not only that the Oligocene formation is in great 

 part, if not wholly, absent from the southern half of the peninsula, where 

 it is replaced by the Miocene and Pliocene, but that even in the north its 

 proper limits, as far as the determination of an absolute horizon is 

 concerned, have probably not been satisfactorily ascertained. Thus, the 

 foraminiferal rock of Tampa, containing the supposed nummulite, N. 

 (Orbitolites) Floridanns, and through which it had been correlated with 

 the Vicksburg formation, is very different from the true orbitoitic or 

 nummulitic rock which is distinctively characteristic of the Oligocene 

 districts of the further north and the interior. Indeed, it contains nothing 

 in common with this rock, but very much that is distinctive of itself, and 

 the underlying siliceous rock that forms the floor of Hillsboro River. 

 It may, nevertheless, be Oligocene, but in that case it in all probability 

 represents a higher horizon than the same formation further to the north. 

 The reasons for considering the formation as of Miocene age, and as the 

 partial equivalent of the medial Tertiary deposits of Santo Domingo, are 

 fully set forth in pages 121-22 of this report. 



A few words only need here be said with reference to the theory, advo- 

 cated by Louis Agassiz and Prof. Joseph Le Conte, which held that the 

 peninsula of Florida was of comparatively recent formation, and that it 

 represented in greater part merely an accumulation of successive or con- 

 secutive coral reefs. Our observations, which had already been preceded 

 in the northern part of the peninsula by the researches of Eugene A. 

 Smith, clearly demonstrate the erroneousness of the views hypothetically 

 set forth, and establish beyond a question of doubt that the progressive 

 growth of the peninsula, as far, at least, as Lake Okecchokee, and probably 

 considerably further, was the result of successive accessions of organic 

 and inorganic material, brought into place through the normal methods 

 of sedimentation and upheaval. A full exposition of Prof. Agassiz's 

 views is embodied in his " Report on the Florida Reefs," published in the 

 Memoirs of the Museum of Comparative Zoology for 1880, some twenty- 

 nine years after its preparation. In this paper the author strenuously 

 denies all evidences of upheaval over the greater part of the peninsula, 

 and ascribes the varying elevations, at least of the more southerly por- 

 tions, to upthrows or accumulations of material as depending upon the 

 agency of gales and high-water. Prof. Le Conte, while still adhering to 

 the fundamental ideas expressed in his original paper, published in the 

 American Journal of Science for 1857, in a more recent paper (Science, 

 Dec. 14, 1883) disclaims the agency of coral growths in the formation of 

 the peninsula north of the Everglades. 



