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



Bold Head, which forms the seaward end of the range last referred to, 

 shows in its cliffs several well marked intrusive dikes, weathering yel- 

 lowish and blackish. 



The whole west side of Plover bay, as well as the outer coast beyond 

 it for several miles, consists of gray rocks which are likewise probably 

 granitic. 



The only locality in which the rocks were actually examined in this 

 region, in the short time available, was the east side of Plover bay between 

 port Providence and Emma harbor. They are here, in the main, rather 

 coarse grained, gray biotite-granite, much like that of the west end of 

 Saint Lawrence island, but in places passing into a hornblendic granite. 

 There is also, however, a considerable proportion of gray and reddish 

 porphyritic rock, resembling a mica-syenite or minette, which is prob- 

 ably later in date than the granite and intrusive in it. No strictly 

 volcanic rocks of any kind were seen in this vicinity, nor were any strati- 

 fied rocks observed. 



The general description of this part of the Siberian coast above given 

 will show that superficial earthy deposits are not abundant, but there 

 are in the vicinity of Plover bay some deposits of this kind which 

 attracted special attention. 



The point on the outer coast immediately east of the valley of lake 

 Moore, terminates in an apron-like flat of land which breaks off seaward 

 in a IcTw cliff, apparently formed of hard clay, weathering to a fawn- 

 color and thickly studded with large bowlders which lie more or less 

 definitely in regular lines, giving a stratified appearance to the whole. 

 Material of the same kind is preserved in the angle of the next bay 

 nearest to Bold Head. It was also seen from a distance to form the 

 coast along the bottom of the bay into which Reindeer river flows, on 

 the opposite side of the entrance of Plover bay, and again occurs in two 

 places on Emma harbor on the west side, a little within the entrance to 

 the harbor and at its southern bay. 



The last named locality was the only one actually examined on the 

 ground. The deposit is here bluish gray where freshly exposed, and is 

 a rather hard clay with a considerable proportion of coarse sand and 

 gravel, containing many bowlders of somewhat varied lithologic 

 character. These are subangular in form, but none were found which 

 actually showed glacial scratching, neither were any shells found in the 

 mass. The deposit, nevertheless, undoubtedly represents a species of 

 bowlder-clay. It does not anywhere take the form of definite terraces, 

 but as it is nowhere seen, or at least not in any considerable mass, at a 

 greater height than about 200 feet above the sea, while it is occasionally 

 rather wide spread below this level, it may be assumed as a whole to 



