TRANSACTIONS OF WAGNER 

 1548 



TERTIARY FAUNA OF FLORIDA 



panied by a uniform and mild climate even into the Arctic regions — was the 

 great extension of brackish-water deposits, lake beds, lignitiferous and leaf- 

 bearing strata, while the purely marine sediments were largely peripheral. 



In North America, in the coastal region, the series which we have referred 

 to the Oligocene was similarly marked by wide extension of brackish-water 

 sediments about the Mississippi embayment, more or less lignitiferous, with 

 peripheral marine sediments. On the northwest coast a large proportion of 

 the lignite beds are probably referable to this epoch. Until recently distinctive 

 marine Eocene was unknown north of Puget Sound. During the Harriman 

 expedition to Alaska, however. Dr. Palache was fortunate enough to discover 

 much distorted uplifted and broken marine sediments with a fauna which, 

 though small and badly preserved, I was able to recognize as typically Eocene. 

 This occurred on the Alaskan peninsula, and these rocks are certainly below 

 the nearly horizontal un'metamorphosed sediments of the Kenai formation 

 which contain most of the Alaskan lignite beds. The latter pass slowly and 

 without perceptible break or unconformity into inarine shallow-water conglom- 

 erates and shales carrying a typical marine Miocene invertebrate fauna. These 

 lignite and leaf beds were referred to the Miocene by Heer, but Starkie Gardner 

 and others have shown that they are Eogene. I have described a similar fauna 

 and succession from the northeastern part of the Okhotsk Sea.* 



Since the condition of the true Eocene sediments indicates great physical 

 changes here before the deposition of the Kenai beds, and since a reasonable 

 proportion of Miocene forms occur in the plants derived from them, the con- 

 clusion that this portion of the boreal lignite-bearing rocks should be regarded 

 as Oligocene is irresistible. 



The marine Oligocene sediments of the southern coast are at first char- 

 acterized by the appearance of vast numbers of foraminifera, the species in 

 some cases identical with European forms referred to approximately the same 

 relative place in the Tertiary column. The organic limestones characterized 

 by the presence of myriads of Orbitoides reach a remarkable thickness ; the mass 

 of this limestone, which forms the substructure of the Floridian peninsula, 

 has been drilled to a depth of more than two thousand feet without definitely 

 reaching the subjacent Eocene. Towards the end of this sedimentation num- 

 mulites make their appearance for the first time in our Tertiary, and the 

 echinoid fauna is so similar to some of that in the European Oligocene as to 



* Proc. U. S. Nat. Museum, xvi.. No. 946, pp. 471-478, 189,3. In this paper, as in 

 other publications of the time, the term Miocene had not yet been discarded. 



