GEOLOGY OF MOOSE RIVER GOLD DISTRICT — WOODMAN. 25 



the strike ; and furthermore, the outcrops .ind artificial exposures 

 are not so placed as to make the exact delimitation of this 

 horizon easy. 



Interhedcled veins, and distribution of strikes and dips. — 

 Most of the interpretation of structure rests, then, upon two 

 series of data- — ^the attitude of the stratified veins, and the dis- 

 tribution of strikes and dips in the sediments. In small areas 

 and for short distances, recognition of definite horizons in the 

 strata is also possible. The distribution, attitude and character- 

 istics of the bedded veins serve well within certain limits ; but 

 beyond a fault these criteria may occasionally fail, especially if 

 the displacement be large, or the veins near a point where they 

 die out or cut across the strata to another horizon, as they do in 

 a few places. Yet veins are frequently the only horizon markers 

 available in measuring a fault. Taken in* connection with the 

 distribution of strikes and dips of the sediments, and the litho- 

 logical character of the strata on the hanging and foot-walls of 

 vein belts, they form part of a fairly secure group of data. 



SEDIMENTS. 



General distribution. — Nortli of the settlement, beginning 

 two or three areas beyond the Copper lead, the rocks are chiefly 

 quartzite for nearly three miles. Here and there thin slate 

 strata are intercalated, but the proportion of argillaceous 

 material is small. South of the mines, starting at the third or 

 fourth tier of areas south of block 1, quartzite again stretches 

 for several miles. The exact proximal limits of these whin* 

 zones cannot be given, on account of the few natural outcrops 

 and the absence of artificial openings ; but the margin of error 

 is small. 



Between these limiting whin areas is a broad belt character- 

 ized by lustrous black slate, often somewhat schistose; essentially 



*This quartzite is called " whin " by miners throughout the province. The term, 

 ■used throughout the gold mining part of the province for sandstones, arenaceous slates 

 and quartzites was originally employed by Hutton in Scotland, to designate certain 

 flheets of trap, and in Cornwall still has a similar meaning. 



