556 



The Siliceous Limestones. 



These beds form here, as in other parts, a thick series 

 that are more or less calcareous, but varying much in com- 

 position. Sometimes the silica is generally distributed 

 throughout the limestone, while in other cases there are 

 alternating lines and bands of calcareous and siliceous 

 material. All the calcareous beds on the north side of the 

 Cathedral-rock Creek appear to belong to this division. The 

 area occupied by them gradually narrows in a northerly 

 direction until, in about a mile from Melrose, the beds run 

 out against the steep slopes of the mount, and the quartzites 

 of the latter come down to the level of the plain, but the 

 rock features at the base of the mount are obscured by a 

 thick veil of talus. 



The foot hills, immediately opposite to Melrose, form 

 three moderately distinct ridges that run parallel with the 

 mount and have a height of about 300 feet. These hills, in 

 places, are connected with the mount by cross ridges or spurs. 

 With the exception of the eastern slopes of the outer ridge 

 (which consist of the purple-slates series) they are all in- 

 cluded within the siliceous-limestone zone. 



On account of the broken and disturbed condition of the 

 rocks within this area it is almost impossible to trace con- 

 nected outcrops along the strike, as many outcrops appear to 

 be isolated and to possess very divergent lines of strike in 

 relation to each other. 



The most northerly extension of the calcareous beds 

 observed was an outcrop of impure limestone in Sec. 339, 

 over the fence, on the right hand side of the road, a little 

 to the south-west of the refuse depot. A little further to the 

 southward slates are seen having a dip to the N.W. at 50° 

 and a strike directed towards the mount. 



Going southward — about in a line with the police station 

 — on the western side of the first (most easterly) ridge, there 

 are outcrops of brecciated rock, including a limestone with 

 foreign fragments closely cemented in the mass and with 

 veins of calcite. Slates on its western side dip S.W. at 70°. 

 Lower down the same slope is an impure buff-coloured lime- 

 stone, exposing a face 16 feet in thickness, with a dip S.W. at 

 43°. This bed is overlain by soft sand-rock, passing into 

 siliceous and slaty fault-breccia ; a similar rock forms a con- 

 spicuous ridge of outcrop in the valley a little further to the 

 south. 



On the top of the second (middle) ridge are outcrops of 

 calcareous shale and a calcareous brecciated rock mixed with 

 shaly material; dip, N. 20° W. at 83°. On the western 

 slopes of this ridge there are further brecciated rocks, and 



