CHAP. IX.] 



GEOLOGICAL CLIMATES. 



195 



Warm Arctic Climates in early Secondary and Faloeozoic times, 

 — The evidence we Lave already adduced of the mild climates 

 prevailing in the Arctic regions throughout the Miocene, Eocene, 

 and Cretaceous periods is supplemented by a considerable body 

 of facts relating to still earlier epochs. 



In the Jurassic period, for example, we have proofs of a mild 

 Arctic climate, in the abundant plant-remains of East Siberia 

 and Amurland, with less productive deposits in Spitzbergen, 

 and at Ando in Norway just within the Arctic circle. But even 

 more remarkable are the marine remains found in many places 

 in high northern latitudes, among which we may especially 

 mention the numerous ammonites and the vertebrae of huge 

 reptiles of the genera Ichthyosaurus and Teleosaurus fouad in 

 the Jurassic deposits of the Parry Islands in 77° N. Lat. 



In the still earlier Triassic age, nautili and ammonites in- 

 habited the seas of Spitzbergen, where their fossil remains are 

 now found. 



In the Carboniferous formation we again meet with plant- 

 remains and beds of true coal in the Arctic regions. Lepido- 

 dendrons and Calamites, together with large spreading ferns, 

 are found at Spitzbergen, and at Bear Island in the extreme 

 north of Eastern Siberia; while marine deposits of the same 

 age contain abundance of large stony corals. 



Lastly, the ancient Silurian limestones, which are widely 

 spread in the high Arctic regions, contain abundance of corals 

 and cephalopodous mollusca resembling those from the same 

 deposits in more temperate lands. 



Conclusions as to the Climates of Tertiary and Secondary jperiods. 

 — If now we look at the whole series of geological facts as to the 

 animal and vegetable productions of the Arctic regions in past 

 ages it is certainly difficult to avoid the conclusion that they 

 indicate a climate of a uniformly temperate or warm character. 

 Whether in Miocene, Upper or Lower Cretaceous, Jurassic, 

 Triassic, Carboniferous or Silurian times, and in all the 

 numerous localities extending over more than half the polar 

 regions, we find one uniform climatic aspect in the fossils. 

 This is quite inconsistent with the theory of alternate cold 

 and mild epochs during phases of high excentricity, and 



0 2 



