70 IF. H. Twenhofel — Geologic Bearing of the 



is considerable evidence to show that the island is in a process 

 of elevatictn with respect to sea level. Should this continue, 

 vegetation will take possession of the then elevated terrace 

 and a belt more than two hundred and eio;hty miles long with 

 an average width given above will be given over to the forma- 

 tion of peat. 



Inferences of Origin after JBxrial. 



These deposits if entombed and metamorphosed into coal 

 will contain land and marine fossils, the latter perhaps being 

 greater in number ; at least, remains of marine organisms 

 are most often seen on the surface of the lowest terrace. 

 They will lie between marine deposits from which they will 

 be separated by unconformities representing great time inter- 

 vals and difKcult to detect except in sections transverse to the 

 old sea cliffs. They will abut against these old cliffs, of whose 

 origin there will be no question, and will have much appear- 

 ance of having been deposited at their bases by transportation. 

 Few trees will stand upright. Most will lie flat. Some may be 

 found with roots upward. The biennial altei-nations of thawing 

 and freezing will have macerated the leaves so that few perfect 

 ones will remain. The helter-skelter and tangled masses of 

 downfallen trees that are now common, if preserved, will 

 simulate the appearance resulting from transportation. The 

 undulations of the peat beds may even lead to the assumption 

 that they are due to ripples. From another standpoint the 

 profuse development of vegetation may be taken as evidence 

 of a genial climate. 



Conclusions. 



The peat beds of this island and the magnificent growth of 

 vegetation have strongly impressed on the writer the fact that 

 a relatively cold climate may support a wonderful luxuriance 

 of plant growth, providing the rainfall be sufficient, and that a 

 warm climate is not an essential condition for the great accumu- 

 lation of vegetable matter. This fact was recognized as early 

 as 1835 by Darwin, who states : " In TeiTa del Fuego trees grow 

 only on the hill-sides ; every level piece of land being invariably 

 covered by a thick bed of peat. * * * The climate of the 

 southern part of America appears particularly favorable to the 

 production of peat. In the Falkland Islands almost every kind 

 of plant, even tiie coarse grass which covers the whole surface 

 of the land, becomes converted to this substance ; scarcely any 

 situation checks the growth. "■^' 



From the polar side of the northern hemisphere Russell 

 describes the tundra of the northern part of Alaska as cover- 

 ing "the whole surface, excepting the faces of steep cliffs and 

 * Naturalist's Voyage Eound the World, 1835. 



