. Annual report . tion itappears to be chiefly serpentine, with a separation of magnetite. A meshlike arrange-ment of highly polarizing minerals, in part fibrous hornblende, surrounds the serpen-tine. The origin of the serpentine was not determined. Serpentine rocks also occurto rhe north of Serpentine lake and are described by Mr. \Y. H. Collins as an altera-tion from olivine rocks. Immediately to the southeast of Dinny lake is a hornblende rock which is cut upby small veinlets of actinolite. A section of the rock shows alternate bands of fibrousgreen hornblende and colorless serpentinous mat
. Annual report . tion itappears to be chiefly serpentine, with a separation of magnetite. A meshlike arrange-ment of highly polarizing minerals, in part fibrous hornblende, surrounds the serpen-tine. The origin of the serpentine was not determined. Serpentine rocks also occurto rhe north of Serpentine lake and are described by Mr. \Y. H. Collins as an altera-tion from olivine rocks. Immediately to the southeast of Dinny lake is a hornblende rock which is cut upby small veinlets of actinolite. A section of the rock shows alternate bands of fibrousgreen hornblende and colorless serpentinous material. To the east of this, on thenorth line of H R 256, the formation is largely serpentine. A light-colored acid rock is interbanded with the greenstone to the west of Obush-kong lake. It is very fine-grained in appearance, consisting largely of crushed quartzand feldspar, with glistening scales of white mica. The dark mineral is chlorite,which is drawn out in fine lines and gives a gneissic texture to the Pig. 75.—Keewatin (K) intruded by diabase (D) east of Cartwrights camp, Everett lake. On W J 15, one of the Leroy group of claims near Leroy lake, a diamond drillhole was put down at an angle of 67 degrees. This passed through quartz diabaseof various grain, but uniformly dark-colored, for 485 feet, when it passed into Kee-watin and was continued for 12 feet. The Keewatin is a fine-grained greenstone,which under the microscope proves to be an altered diabase, as the ophitic texture ofthe diabase may still be discerned. Iron formation occurs to the west of Elkhorn lake, along the boundary line ofMilner and Leith, showing as bands of red jaspilyte. The ore, which is very lean, isspecular hematite and magnetite. The bands are only a few inches to a few feet wideand are associated with an amygdaloidal trap, which represents the lava from an oldKeewatin eruption. The vesicles of the original lava are now filled with later min-erals, the most abundant of which are quartz
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectminesandmineralresou
