Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 20, 2025
2-Quartz Biotite Schist. Contact between above dike and amphibolite. A coarse black rock carrying magnetite and pyrites in considerable quantities. Under the microscope some of the biotite has a green coloration from decomposition and is surrounded by strong pleochroic halos. Small grains of secondary pyroxene are numerous. 3-Grand Lake.
Along Grand Lake the rock is a compact amphibolite with a strike S. 78 degrees E. cut by numerous pegmatite dikes, having a strike N. 30 degrees W. and a dip 79 degrees W.. These dikes vary in width from three to twenty feet.
HORNBLENDE-SCHIST is usually black, and composed principally of hornblende, with a variable quantity of feldspar, and sometimes grains of quartz. When the hornblende and feldspar are in nearly equal quantities, and the rock is not slaty, it corresponds in character with the greenstones of the trap family, and has been called "primitive greenstone." It may be termed hornblende rock, or amphibolite.
Between these bands of orthoclase and the neighboring amphibolite are narrow bands of schist One hundred feet south of the above point is a second dike having a similar strike and dip and a width of eighteen feet. A third narrow dike, containing small pockets of magnetite, is twenty-five feet south of the second. Only the first is distinguished by the segregation of the quartz.
First portage opposite Red River S. 45 degrees E. On Caribou Ridge E. At Washkagama Lake S. 70 degrees E. Near Seal Lake N. 85 degrees E. At Wuchusk Nipi S. 75 degrees E. Thirty-two miles above Wuchusk Nipi S. 70 degrees E. By G. M. Richards, Columbia University 1 Pegmatite-Grand Lake. The specimen was taken from a pegmatite dike at its contact with an amphibolite.
Word Of The Day
Others Looking