26 GEOLOGY OF MOOSE KIVER GOLD DISTRICT — WOODMAN. 



different from the slate of the Halifax formation, which is well 

 exposed on the road north from the mines. There are quartzite 

 strata within this zone, but they are comparatively few and 

 narrow. In them, as in the more abundant ones to the north 

 slate lenses with rounded edges are occasionally found. It is 

 the extent of this slate belt, at least 1,500 feet wide across the 

 strike, which constitutes one of the unique features of the dis- 

 trict. All the ore-bearing veins are situated in it, even though 

 many of them lie at the contact of slate with thin strata of 

 quartzite. 



The plunging of the folds east and west is not sufficient to 

 bring the bordering quartzites of the north and south around the 

 ends of the anticlines — at least, within the limits of the survey. 



Characteristics: slates. — The argillaceous material varies 

 from a soft lustrous slate to one that is as hard and dense as the 

 best roofing slates. In both the composition is chiefly kaolin, 

 finer in the former, and somewhat lighter colored in the slide. 

 Most of the characteristics seen in thin section are metamorphic. 

 The color in the field is due largely to the same cause, but the 

 firmness has for its primary source the texture of the mass,, 

 allowing the metamorphic changes to act differently in different 

 cases. On the whole, the coarser the slate the less it has been 

 shattered by cleavage. 



Characteristics : quartzites. — The coarser sediments griide 

 imperceptibly into the pelites in places, but in the slide a sharper 

 line of demarcation is usually present than would be expected. 

 The quartzites have as their chief constituent fine and well 

 rounded grains of quartz. The cement is partly secondary silica, 

 but so much calcite is present that it is difficult to see in some 

 specimens what can be the origin of the granular gleam charac- 

 teristic of fresh quartzite surfaces, and highly developed in the 

 psammites of Moose River. 



No distinctly felspathic material was seen in the slides, and 

 little kaolin in any but the finer whin. Tiiere is, however, a 

 considerable amount of muscovite and biotite. While some of 



