280 G. 31. DAWSON ON" THE SUPERFICIAL GEOLOGY OF 



neighbouring inlets in such a position as to suggest that they may 

 in part represent a moraine marking a stage in retreat of the ice. 

 They form the projecting points of a comparatively shoal bank off 

 these inlets, which, in their upper parts, are very deep. Boulders 

 here occur in great abundance on the beaches, and are probably 

 derived from a Boulder-clay or morainic material underlying the 

 well-bedded deposits. 



Glaciation of the Queen- Charlotte Islands. 



These islands were the subject of geological examination in 1878. 

 They form a compact archipelago widely separated from the southern 

 extremity of Alaska to the north, and the western coast of British 

 Columbia to the east, and may be regarded as a partly submerged 

 mountain system, the axis of which lies in a N.N.W.-S.S.E. bearing. 

 In its central part summits surpassing 4000 feet, and still bearing 

 patches of perennial snow, are frequent, but it falls at both ends. 

 On the north-east side of the mountain axis, at its north end, is a 

 wide triangular attachment of flat land forming the greater part of 

 Graham Island. 



In these islands we find everywhere evidence of the descent of 

 glacier-ice from the mountains toward the sea, but (with one im- 

 portant exception subsequently noticed) none of the passage across 

 the group of any more ponderous ice-mass. The channels and fiords 

 penetrating the southern portion of the islands show in general di- 

 stinct and heavy glaciation which has evidently been local in cha- 

 racter, the scoring and grooving being parallel to the main directions 

 of the valleys, and changing with their course. In Houston- 

 Stewart Channel, separating Prevost and Moresby Islands, the ice 

 has evidently flowed from the axial mountains both eastward and 

 toward the open Pacific to the west. Many of the boulders of the 

 beaches are distinctly glaciated, and, as they lie in some places rudely 

 packed together, seem to have been little disturbed since they were 

 deposited by the ice. Sands, clays, and other detrital deposits re- 

 ferable to the period of glaciation are here almost entirely wanting, 

 and the water round the coast is deep. 



Further north, near Laskeek, where the width of the islands 

 becomes greater, there is evidence, in the comparatively slight de- 

 gree in which the rocks at the outer ends of the inlets are glaciated, 

 that the glaciers did not long stretch much further out than the pre- 

 sent coast-line. At Cumshewa Inlet (lat. 53°), and further north at 

 Skidegate Inlet, the character of the coast changes, becoming low ; 

 but both these inlets still head in the high axial mountains of 

 the group. Traces of the glaciers of these inlets are found nearly 

 to their mouths ; but while the upper parts are still deep and fiord- 

 like, they are partly blocked at their seaward extremities by trans- 

 verse bars, and shallow water extends far off shore. 



Further north a series of fiord-like valleys are still found pene- 

 trating the eastern side of the mountainous axis of Graham Island, 

 and the shoal-water found off Cumshewa and Skidegate is repre- 



