158 O. M. Dawson — Geology of British Columbia, 



In describing the rocks, those of Tertiary and Cretaceous age of 

 the coast will first he noticed, next those of the intei'ior of the pro- 

 Yince referable to these periods, and lastly the older underlying 

 metamorphic rocks. 



Tertiary. — The Tertiary rocks do not form any wide or continuous 

 belt on this part of the coast, as is the case farther south. They are 

 found near Sooke, at the southern extremity of Vancouver's Island, 

 in the form of sandstones, conglomerates, and shales, which are some- 

 times carbonaceous.^ Tertiaiy rocks also probably occupy a consider- 

 able area about the mouth of the Fraser River ; extending southward 

 from Burrard Inlet, across the International boundary formed by the 

 49th parallel, to Bellingham Bay and beyond. Thin seams of lignite 

 occur at Burrard Inlet. Sections of the Tertiary rocks at Bellingham 

 Bay are given in Dr. Hector's official report. Lignite beds were 

 here some years ago extensively worked, but the mine has been 

 abandoned owing to the superior quality of the fuels now obtained 

 from Nanaimo and Seattle. About the estuary of the Fraser the 

 Tertiary beds are much covered by drift and alluvial deposits, and 

 are consequently not well known. Lignites, and even true coals, 

 have been found in connexion with them, but so far in beds too thin 

 to be of value. Fossil plants from Burrard Inlet and Bellingham 

 Bay have been described by Newberry and Lesquereux, and these 

 are supposed to indicate a Miocene age for the deposits.'^ 



Much farther north, in the Queen Charlotte Island, the whole 

 north-eastern portion of Graham Island has now been shown to be 

 underlain by Tertiary rocks, which produce a flat or gently un- 

 dulating country, markedly different from that found on most parts 

 of the coast. The prominent rocks are of volcanic origin, including 

 basalts, dolerites, trachytic rocks, and in one locality obsidian. 

 Numerous examples of fragmental volcanic rocks are also found. 

 Below these, but seen in a few places only, are ordinary sedimentary 

 deposits, consisting of sandstones or shales, and hard clays with 

 lignites. At a single locality on the north end of Graham Island, 

 beds with numerous marine fossils occur. These, in so far as they 

 admit of specific determination, represent shells found in the later 

 'Tertiary deposits of California, and some of which are still living on 

 the north-west coast ; and the assemblage is not such as to indicate 

 any marked difference of climate from that now obtaining.^ 



The Tertiary rocks of the coast are not anywhere much disturbed 

 or altered. The relative level of sea and land must have been 

 nearly as at present when they were formed, and it is probable that 

 they originally spread much more widely, the preservation of such 

 an area as that of Graham Island being due to the protective capping 



1 Eeport of Progress, Geol. Survey of Canada, 1876-77, p. 190. 



"^ In the geology of the XJ. S. exploring expedition, Prof. Dana describes some 

 Tertiary plants from Birch Bay. These were afterwards reported on by Newberry, 

 Boston Joiu-n. of Nat. Hist. vol. vii. No. 4. See also American Journal of Sc. and 

 Arts, 2nd series, vol. xxvii. p. 359, and vol. xxviii. p. 85. Eeport on the Yellow- 

 stone and Niusain expedition, 1869, p. 166. Annals Lye. of Nat. Hist, of N. Y., 

 vol. ix. April, 1868. 



3 Eeport of Progress, Geol. Survey of Canada, 1878-9, p. 84 B. 



