390 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



morphosed group of rocks bounding the Osoyoos batholith on the west. In all, 

 some eighty square miles of the five-mile belt is known to be underlain by thi3 

 series. 



Notwithstanding the considerable area covered by the series, a rather pro- 

 longed field and laboratory study of its constituent rocks has failed to produce 

 satisfactory details as to their succession or position in the geological time- 

 scale. One of the major difficulties in the field work was found in tho excep- 

 tional continuity of the Glacial-drift cover which mantles the bed-rock to a 

 degree unequalled in the rest of the Boundary belt. An example of the rarity 

 of outcrops may be cited from the field notes of the season of 1904, during 

 which a traverse of ten miles east and north of Sidney post-office led to the 

 discovery of only three small outcrops. For this reason, although the country 

 is very accessible, the facts to be cited concerning the Anarchist series are 

 merely those of a geological reconnaissance. 



The rocks of the series belong to four classes, — quartzite, phyllitic slates, 

 limestones, and greenstones. Where more metamorphosed these become, respec- 

 tively, micaceous quartzite, mica schist, marble, and amphibolite. The dominant 

 species are quartzite and phyllite, apparently in about equal proportion. 

 Greenstone is next in importance, while the limestone is represented only in a 

 few local, pod-like masses generally from 200 to 100 feet or less in thickness. 



The quartzite is a gray to green, very hard rock, commonly sheared so as 

 to simulate the associated, more argillaceous rock in its fissility. Under the 

 microscope the quartzite is quite normal, presenting the usual appearance of 

 recrystallized, interlocking quartz-grains with variable amounts of biotite, 

 sericite, and chlorite in minute foils. Pyrite is a common metamorphic acces- 

 sory. The rock is sometimes slightly calcareous and in a few thin beds passes 

 L>ver into silicious limestone. Much more often it is greatly enriched in 

 micaceous elements which have evidently been derived from relatively abundant 

 argillaceous matter; recrystallization is so thorough that in none of the thin 

 sections examined was original argillaceous substance to be found. 



The same is true of the old argillites proper. They are now noncrystalline, 

 though with the fine grain of true phyllite or of metargillite. Where the 

 metargillite crops out it is possible to determine the attitude of the true 

 bedding, but such fortune is exceptional and the only structural plane usually 

 to be discerned is the schistosity. The colour of the phyllite or metargillite 

 varies from dark gray to bluish-gray and greenish, with dark slate-gray as the 

 dominant tint. The essential minerals are the same as in the quartzite, simply 

 occurring here in different proportions. The dark colour of the rock is doubtless 

 chiefly due to the inclusion of carbonaceous matter in small amount. Like the 

 quartzites the phyllitic rocks are traversed by multitudes of quartz veinlets, and 

 at many points by huge veins of white quartz. 



The limestone pods can never be followed far across-country ; they represent 

 beds that have been sheared into great fragments as the enclosing argillaceous 

 rock underwent its heavy mashing and dynamic metamorphism. The limestone 

 is generally massive, rather pure, and of a light bluish-gray colour; sometimes 



