118 



G. M. DAWSON — COASTS OF BERING SEA AND VICINITY. 



various places visited. The time available for observations ashore was 

 usually very limited, and thus, but for the fact that so little is yet known 

 respecting the geology of the whole region, such notes as it was possible 

 to make would possess ver}^ little inherent value. As it is, they may be 

 accepted as a slight contribution to our knowledge of a portion of the 

 globe of which but a few limited spots have yet come under the observa- 

 tion of any trained geologist. 



Dr W. H. Dall has lately collected in a single work a precis of nearly 

 all the authentic data relating to the American shores and islands of 

 Bering sea.* This work is devoted specially to the Neocene formations, 

 but these include a great part of those known to occur, and references 

 are besides given in it to various older formations. Allusion is frequently 

 made to this work of Dr Dall's in the sequel, and in so far as they cover 



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Figure 1. — Map of Coasts and Islands of Bering Sea. 



the same ground the notes here set down may be regarded as merely 

 supplementary to those he has published either as the result of his own 

 observations or in the form of extracts from older works. Thus in what 

 foUoAvs respecting the Aleutian islands, it will be found that only those 

 touched at or seen by the writer are mentioned, and, generally speaking, 

 that greater attention is given to places about w^hich the known facts are 

 particularly scanty or altogether wanting, and to those more general 

 physiographic features of the land to which the attention of the earlier 

 explorers was not directed. 



Mr W. F. Ferrier, lithologist to the Geological Survey of Canada, has 

 been so kind as to look over the rock specimens brought back, and in 

 some cases has examined them microscopically in thin sections for the 

 purpose of their determination. 



*Bnll. U. S. Geological Survey, no. 84, 1892, p. 234 et seq. 



