339 



KUomet^es summit at Malahat nearly to 17 Mile Post, 

 is the Wark gabbro-diorite gneiss, numerous 

 outcrops of which are seen near the track and 

 on the slopes up to the level of the uplifted 

 Tertiary peneplain. Frequent apophyses of 

 the Colquitz quartz diorite gneiss are also 

 seen, in places so numerous as to form a breccia 

 of the two rocks. From the summit the rail- 

 road descends along the west slope of the 

 maturely glaciated, transverse, north-south val- 

 ley, which has been converted into a fiord, 

 called Saanich inlet. The southern or typical 

 fiord portion, along the side of which is the 

 railroad, is called Finlayson arm. To the south 

 of 17 Mile Post for nearly five miles (8 km.) 

 the road traverses an area of schistose volcanic 

 rocks, cut by two intrusive masses of the 

 Colquitz and Wark gneisses. The volcanics 

 are largely fragmental, of the composition of 

 dacites and andesites, and are interbedded with 

 sedimentary material. They are greatly de- 

 foimed and their dips are nearly vertical. 

 They have been mapped with the Vancouver 

 volcanics but are interbedded with and transi- 

 tional into the Leech River slates, which lie 

 to the south and which are probably Palaeozoic. 

 At 15 and 14 Mile Posts, canyons, called res- 

 pectively Arbutus and Niagara canyons, are 

 crossed on high bridges. They are the spillways 

 of hanging valleys. South of the schistose 

 volcanics are the Leech River slates, greatly 

 deformed, contorted and cut by quartz veins. 

 At the bend in the railroad west of Goldstream, 

 the Goldstream river is crossed. Here the Leech 

 River slates are covered by stratified coarse 

 gravels, which constitue the top-set beds of the 

 Colwood delta, built during the recession of 

 one of the Vashon glaciers which occupied Gold- 

 stream valley. To the north of the bridge the 

 Colwood gravels are seen resting on the blue 

 Vashon till. From the bridge to Goldstream 

 the railroad follows the profound overthrust 

 fault which separates the Palaeozoic Leech River 

 slates from the Eocene Metchosin basalts, 

 35069— 5B 



