ELY GREENSTONE. 133 



Returning to the southern arm of the gTeenstone, we find it covering 

 the major portion of T. 63 N., R. 10 W., with a small portion of T. 64 N. 

 As we follow it eastward into T. 63 and T. 64 N., R. 9 W., we find that its 

 width is materially reduced. This results from the fact that in this area we 

 are upon a great anticline plunging to the east, around which wrap the 

 younger formations. These are likewise infolded in synclines within the 

 greenstone, as is to be expected, for instance, in sec. 17, T. 63 N., R. 9 W. 

 In the southern portion of T. 64 N., R. 9 W., this infolding is beautifully 

 shown. As a result of this the g-reenstone is divided into a number of 

 narrow belts having, in general, an east-west trend, each belt being 

 separated from every other, and from the main mass of the greenstone to 

 the south, by a trough containing" later sedimentary deposits. As results 

 of cross folding the greenstone occurs in a number of places in anticlinal 

 boss-like areas plunging down under, the sediments and completely 

 surrounded by them. 



From the center of R. 9 W. eastward this greenstone is totally wanting 

 vintil we reach the center of R. 8 W., where another anticlinal area of 

 greenstone is found. This is surrounded on three sides by overlapping 

 sedimentaries, the fourth, the eastern side, being cut off by the gabbro. 

 As we go farther east we find that the greenstone is not continuous over 

 any very broad areas. It occurs for the most part in rather narrow, long 

 belts; for instance, such a belt begins on the point projecting westward 

 into Knife Lake in sec. 21, T. 65 N., R. 7 W., and extends thence east- 

 ward into sec. 11, T. 65 N., R. 6 W., with a maximum width of about 

 one-half mile. Alongside this belt, however, there are small isolated 

 bosses surrounded by the younger rocks, as may be seen in the southwest 

 quarter of sec. 17 and the southeast quarter of sec. 18, T. 65 N., R. 6 W. 

 Similar greenstone areas occur south of Knife Lake in sees. 29, 30, and 

 31, T. 65 N., R. 6 W., and in sees. 25 and 36, T. 65 N., R. 7 W., and other 

 small areas occur also in sees. 25, 26, and 27, T. 65 N, R. 6 W. Consid- 

 erably larger is the greenstone massive forming the ridge upon which the 

 Twin Peaks are prominent points, extending along the line between Ts. 

 64 and 65 N. eastward to Gobbemichigamma Lake. Still larger is the 

 area that extends over sees. 18 and 19, T 65 N., R. 6 W., eastward to 

 sec. 27, T. 65 N., R. 4 W., having an east-west length of approximately 

 10 miles. This last belt starts in at the west with two westward-plunging 



