128 



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



such regularly conical forms, but taken as a whole the volcanoes of the 

 Aleutian chain, as compared with those of Kamchatka, are but stunted 

 and irregular, the general impression conveyed by such a comparison 

 being that of the much greater age and dwindling condition of vulcanism 

 in the Aleutian region, where the processes of waste have for a long time 

 outstripped those of accretion. 



Besides the dominant volcanic cones, covered or heavily striped with 

 snow, there is much irregularly mountainous or hilly country of lower 

 elevation. Very possibly this also may be largely volcanic in origin, 

 but if so it has been denuded and sculptured into ordinary systems of 

 hills and valle3^s like the mountains of most of the Aleutian islaiids 

 already described, probably in later Tertiary times. 



There is also, along this part of the coast, evidence of a plane of marine 

 denudation. This plane was observed particularly about cape Japounski 

 or Tshipunski, where it gives form to the end of the promontory, and 

 spreads along the bases of the higher hills sometimes with a width of a 

 mile or more. At cape Japounski (estimating from the heights given 

 on the charts) this plane is, in its higher parts, 700 to 800 feet above the 

 present sealevel, but declines gradually to its seaward edge, where it is 

 about 600 feet in height. Traces of the same or a similar plane, though 

 at a somewhat lower level, were again seen in the immediate neighbor- 

 hood of Avacha bay. 



At cape Japounski this flat bordering land or narrow plateau has 

 itself been since cut through by narrow V-^l^^ped valleys which run 

 from the inland hilly tract to the sea.* The excavation of the later 

 valleys seems to have occurred while the land stood some fifty or one 

 hundred feet below its present level, for the valleys are not cut down to 

 the sea, but terminate seaward at such heights above the waterline. The 

 coast cliff may be represented diagramatically thus : 



Figure Z.— Diagram illustrating the Profile of the Coast Cliffs at Cape Japounski. 



That the plateau of cape Japounski is not one of deposition, but subse- 

 quently impressed, is shown by the fact that the underlying rocks are 

 seen in the seacliffs, particularly near the extremity of the cape, to be 

 well stratified and to be inclined at various angles, which are sometimes 

 rather high and are entirely independent of the level contour of the 



* The general appearance of cape Japounski is very well illustrated in view no. 3 on chart no. 54, 

 U, S. Hydrographic office, 



