100 B GEOLOGICAL SURVEY OF CANADA. 



Hollows left by by debris from floating ice from the larger glaciers of the main- 



giaciers. land, the sea levelling and spreading abroad the detritus, and pre- 



venting the formation of any well marked terminal moraines by the 

 island glaciers. The basins now occupied by the two expansions of 

 Masset Inlet and by Naden Harbour lie along the border of the high 

 central axis of the islands, and are bounded north-eastward by the low 

 plains of drift material. The rocky beds of these depressions may 

 have been shaped to some extent by the ice, but the absence of drift 

 material from their areas, and especially of erratics derived from the 

 coast of the mainland, which are abundant over the drift-covered 

 region to the north-east, are, with their situation, good reasons for 

 supposing that they mark the areas last covered by glacier ice, and 

 from which the ice eventually retreated with some rapidity, leaving 

 the hollows formerly Occupied by it to become first inlets, and then 

 with increasing elevation in some instances lakes. 



It is probable that complete explorations will reveal a series of such 

 hollows along the whole eastern flank of the mountain ranges of the 

 islands. Besides those just mentioned, there are two very large lakes 

 on the same line between the upper part of Masset Inlet and Naden 



Submerged Harbour. One of these discharges into the latter, the other by the 

 Ain Eiver into Masset Inlet. There is also at least one similar lake 

 between the head of Masset Inlet and Skidegate. None of these have, 

 so far as I know, been visited by any white man. In Skidegate Inlet 

 and in Cumshewa Inlet, both obstructed at the mouth by bars, and 

 with comparatively shoal water far off shore, while deep toward their 

 upper parts ; we seem to have exactly the same feature, though in a 

 partially submerged condition. Further south, with high mountains 

 rising abruptly from the water, the glaciers even at this period of their 

 decadence must have pushed some distance seaward. There must also 

 have been less material supplied from them, and little from the main- 

 land, owing to its greater distance. In the halibut banks off Laskeek, 

 however, it is possible that traces of the position of the front of the 

 glaciers are again found. 



Accumulations In Hernando and Savary Islands, strewn with boulders and formed 



about the J ' 



mouth of Bute above at least of stratified deposits, we may have the remnants of a simi- 

 lar sea-modified moraine of the glacier fed by Bute and other neighbour- 

 ing inlets. Features somewhat similar characterize most of the fiords 

 and inlets of the coast of the mainland, and west ooast of Vancouver 

 Island, and though in some instances marine currents may have been 

 efficient in silting up and reducing the depth of the inlets near their 

 mouths, while the upper reaches have remained deep; it is by no means 

 improbable that moraine accumulations, spread abroad by water beyond 

 the front of the glaciers, may account for this arrangement in many 



