122 gke0ege meecee dawson on the 



5. Sfmmaey. 



1. The character of the rock-striation and fluting on the south- 

 eastern peninsula of Yancouver Island shows that at one time a 

 great glacier swept over it from north to south. The glacier must 

 have filled the Strait of Georgia, with a breadth, in some places, of 

 over 50 miles, and a thickness of ice near Victoria of considerably 

 over 600 feet. Traces of the glacier are also found on San-Juan 

 Island and the coast of the mainland. 



2. The deposits immediately overlying the glaciated rocks, besides 

 hard material locally developed, and probably representing moraine 

 profonde, consist of sandy clays and sands, which have been arranged 

 in water, and in some places contain marine shells. These, or at 

 least their lower beds, were probably formed at the foot of the 

 glacier when retreating, the sea standing considerably higher than 

 at jjresent. 



3. Observations in the northern part of the Strait of Georgia, and 

 the fjords opening into it — where the sources of the great glacier 

 must have been — show ice- action to a height of over 3000 feet on 

 the mountain-sides. The fjords north of the Strait of Georgia show 

 similar traces. Terraces along the coast of the mainland are very 

 seldom seen, and have never been observed at great elevations. 



4. In the interior plateau of British Columbia there is a system 

 of glaciation from north to south, of which traces have been observed 

 at several localities above 3000 feet. Subsequent glaciation, 

 radiant from the mountain-ranges, is also found. 



5. The superficial deposits of the interior may be classified as 

 unmodified and modified. The former, representing the Boulder- 

 clay, hold many water-rounded stones, with some glacier-marked, 

 and occurs at all heights up to over 5000 feet. The latter charac- 

 terize nearly all localities below 3000 feet, and are most extensively 

 developed in the northern low country, where they appear as a fine 

 white silt or loess. 



6. The interior is marked with shore-lines and terraces from the 

 present sea-level up to 5270 feet, at which height a well-marked 

 beach of rolled stones occurs on Il-ga-chuz Mountain. 



7. Moraines occur in great numbers. Some of the moraine-like 

 accumulations may have been formed in connexion with the north- 

 to-south glaciation. Most of those now seen, however, mark stages 

 in the retreat of glaciers towards the various mountain-ranges. 

 The material of the moraines resembles that of the Boulder-clay, but 

 with water-rounded stones even more abundant. 



8. The sequence of events in the interior region has been : — 

 glaciation from north to south, with deposit of Boulder- clay ; for- 

 mation of terraces by lowering of water- surface, accompanied or 

 followed by a warm period ; short advance of glaciers from the 

 mountains contemporaneously with formation of lower terraces; 

 retreat of glaciers to their present limits. Glaciation of Yancouver 

 Island may have occurred during both the first and second cold 

 periods, or during the second only. 



