536 INDEX TO THE STRATIGRAPHY OF NORTH AMERICA. 



Reports later than Dawson's give much local detail regarding the Triassic as 

 it occurs in the counties of Nova Scotia adjoining the Bay of Fundy. Fletcher^' 

 describes the distribution and states: 



The relations of the sedimentary rocks of this formation, with their associated traps, to 

 the older formations have also been described in great detail by Jackson and Alger, Gesner," 

 Sir J. W. Dawson,*" and others. The contact with the older rocks is always clear and unmistak- 

 able, so that there is no ambiguity with regard to the limits of the formation. Sometimes, 

 particularly on the north side of the basia, this junction is a fault; sometimes coarse beds he at 

 a low angle upon and fill inequahties in the underlying rocks of which they are composed. 

 Many of the sandstones are very calcareous. The total thickness of the formation is doubtful. 



In Chfford Brook, east of Valley station, the lowest Triassic rock is a pea and nut conglom- 

 erate lying horizontally on the red slates of Union. On the road to the Telegraph road east 

 of the manganese mines, and also in the neighborhood of the mines, many pieces of Triassic 

 sandstone are in the soil and perhaps point to outliers among the Devonian. 



From the railway station at Valley across the bridge and out the road to the Telegraph 

 road the strata are Triassic, and to the eastward along the Telegraph road and for some distance 

 up the river these rocks are also exposed. In Half Moon Hill Brook the contact with the 

 Devonian is well seen, the Triassic being bright-red, crumbly, coarse sandstones, scarcely more 

 coherent than the sand of a sand pit, with layers of grit, less bright than the other beds, con- 

 taining pebbles an inch in length derived from the red argillites. Lower down is a gray, crumbly 

 flaggy pebbly sandstone, dipping at a low angle, with thin beds and blotches of Ught green. 



In the branch of Farnham's Millbrook which flows from Penny's Mountain are dark brick- 

 red, soft, marly, very fine sandstones, containing patches of gray calcareous sandstone and 

 of coarse conglomerate, with a vertical dip which appears to indicate a fault. In another 

 little brook farther west, brick-red sandstone and nut and egg conglomerate form ledges which 



dip at a very high angle. 



M 9-10. VANCOUVER ISLAND. 



In 1885 Dawson made a reconnaissance of the northern portion of Vancouver 

 Island and determined the presence of Triassic limestone and argillite in an immense 

 series of volcanic rocks, all of which are penetrated by granite intrusions. In 1902 

 the west coast was reconnoitered by Webster ^^ and Haycock,*^^ who identified the 

 same series of rocks but added nothing to Dawson's original description,^^^^ from 

 which the following extracts are made : 



By far the greater part of the area of the northern portion of Vancouver Island is occupied 

 by rocks of volcanic origin, which at first sight and as judged by eastern American analogies 

 might often be supposed to represent formations occupying a very low stage in the geological 

 scale. These volcanic rocks, originally composed of minerals already crystalline, have since been 

 subjected to metamorphism more or less intense, to which, in consequence of their composition, 

 they have easily yielded, and now form, for the most part, rocks which might be spoken of as 

 "traps and greenstones." These frequently show locally little or no evidence of their bedded 

 character. Such rocks, however, when closely examined and followed from point to point, 

 are found to form portions of a stratified series of great thickness, which includes, besides the 

 preponderant volcanic materials, certain argillites and limestones, holding Triassic fossils. 



The greater part of this old volcanic series appears to have been built up of basaltic and 

 trachytic lava flows, alternating with rough volcanic breccias and tuffs largely composed of 

 fragments derived from such flows. These rocks are now represented by hard amygdaloids 

 and agglomerates of general dajk-greenish colors, though often grayish and sometimes reddish 

 or purphsh; by felsites, more or less porphyritic; and by hard, regularly stratified ash beds, 

 which, where the alteration has been most pronounced, are locally changed to hornblendic or 

 micaceous schists. 



" Geology and mineralogy of Nova Scotia, p. 239. 



6 Acadian geology, p. 99; Geol. Jour. London, vol. 4, p. 50, with a map. 



