QUEEN CHARLOTTE ISLANDS. 99 B 



have occurred. During the first, and most intense, there are some Conditions of 

 grounds for the belief that the entire interior plateau was covered by f^fwi. ' :ial 

 a glacier-sheet with a slow southward motion, the gradual disappearance 

 of which was accompanied by a subsidance of the land amounting to 

 several thousand feet, or by the formation of a great lake held in by 

 glacial barriers. It is possible, however, that the north-to-south glaci- 

 ation of the interior may have been effected simultaneously with the 

 deposit of the boulder-clays, without the aid of a great ice-sheet, but 

 by floating ice. The second period seems to have been a temporary 

 advance of glaciers from the various mountain systems, and must have 

 been inconsiderable induration and severity as compared with the first. 

 It is not intended to do more than mention these hypothesis here, to 

 indicate their possible bearing on the explanation to be adopted for the 

 glacial phenomena of the coast. 



On the coast, we find that the great hollow between Vancouver Island Glaciers of the 

 and the mainland must have been blocked with ice, supplied from the 

 mountains of the island and the Cascade or Coast Eange, with, possibly, 

 the addition of ice flowing westward through gaps in the range 

 from the central plateau. The great glacier-mass thus formed, from 

 a position near Chatham Point of Vancouver Island, flowed south-east- 

 ward as the Strait of Georgia glacier, and north-westward as that of 

 Queen Charlotte's Sound, till it reached the ocean in both directions. 

 Local glaciers doubtless filled the inlets of the west coast of Vancouver 

 Island. 



Northward, to the southern extremity of Alaska, the ice discharge 

 of the various inlets may probably have formed a coalescent glacier 

 along the coast, ending seaward near to, or somewhat beyond, the outer 

 points of the present coast archipelago. 



In the Queen Charlotte Islands, with a comparatively limited gather- 

 ing ground, the glaciers were probably much smaller, but the islands, 

 must have been well capped with ice at this time. 



No evidence of a great south-to-north-moving ice sheet has anywhere 

 been found, though it may be remarked that if such had existed at a 

 more remote period, the glaciation of which we can trace the history, 

 would probably have been sufficient to remove it in most places. 



When the Strait of Georgia glacier began to diminish, the sea must ig^ at re i at ; ve . 

 have stood considerably higher in relation to the land than at present, ly hi « uer leTel - 

 and the glaciated rock surfaces became covered about Victoria and 

 Nanaimo with deposits holding marine shells. This must have 

 occurred also in the Queen Charlotte Islands, and to this time are 

 doubtless due the clays and sands of the low north-eastern part of 

 the islands above described. The material of these must have been 

 supplied from the glaciers of the islands themselves, and added to 



