The Green Schists and Associated Granites and Porphyries of Rhode IslandU.S. Government Printing Office, 1907 - 74 Seiten |
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20 feet acid Alaska aplite basin beach bed rock biotite biotite granite black mica biotite bowlders Bull calcite carbonate Carboniferous cent chloride chlorite cm³ coal coarse color conglomerate contains copper County Creek crystals cupric sulphate deposits derricks diabase dike diorite district drills east epidote even-grained texture feet thick feldspar geology gold grains grams granite granite specimen gravels green schist hornblende inches thick Island kaolin Kougarok lime limestone magnetite mass Matanuska mica microcline microgranite miles Millimols mineral mining Mountain Nome occurs oligoclase operations order of abundance orthoclase pegmatite places plant consists porphyry potash feldspar potassium pyrite quarry quartzite reconnaissance region reported rift River Rock structure salt sand schist seams Seward Peninsula shale sheets shows silicates smoky quartz soda-lime feldspar oligoclase stone stream strike surface tributary U. S. Geol valley veins Vinalhaven white mica Yukon
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Seite 206 - SCHRADER, FC, and SPENCER, AC The geology and mineral resources of a portion of the Copper River district, Alaska.
Seite 210 - Reconnaissances in the Cape Nome and Norton Bay regions, Alaska, in 1900,
Seite v - Ransome. 1906. 516 pp., 29 pis. PP 55. Ore deposits of the Silver Peak quadrangle, Nevada, by JE Spurr. 1906. 174 pp., 24 pis. B 289. A reconnaissance of the Matanuska coal field, Alaska, in 1905, by GC Martin. 1906.
Seite 186 - Fine-grained granite, usually occurring in dikes and containing little mica and a high percentage of silica. BASIC. A term applied to rocks in which the iron-magnesia minerals and feldspars with lime and soda predominate, such as diabase or basalts.
Seite 205 - ... quadrangle, Kansas, by Frank C. Schrader and Erasmus Haworth. 1906. 74 pp., 6 pis. B 297. The Yampa coal field, Routt County, Colo., by NM Fenneman, Hoyt S. Gale, and MR Campbell. 1906.
Seite 15 - ... overlying mass of rock but also powerful expansive pressure from below. Had this molten matter been extruded at the surface it would have cooled so rapidly that but few of its constituent molecules would have had time to arrange themselves in geometric order. The process of crystallization would have been arrested by the sudden passage of the material into the solid state, and the product would have been a volcanic glass somewhat resembling that which forms cliffs in Yellowstone National Park....
Seite 35 - ... in joints consists in their discontinuity or intermittence, their strike and dip for the short spaces in which they occur being uniform. HEADINGS. In some places joints occur within intervals so short as to break up the rock into useless blocks. For a space of 5 to 50 feet the joints may be from G inches to 3 feet apart. A group of close joints is called by quarrymen a " heading," possibly because, when practicable, such a mass is left as the head or wall of the quarry.
Seite 186 - A microscopic granular structure sometimes characterizing adjacent feldspar particles in granite in consequence of their having been crushed together during or subsequent to their crystallization. CUT-OFF. Quarrymen's term for the direction along which the granite must be channeled, because it will not split. Same as "hardway.
Seite 206 - B 312. The interaction between minerals and water solutions, with special reference to geologic phenomena, by EC Sullivan.
Seite 52 - ... sheets in the Maine quarries is from one-half to 12 inches, exceptionally even 18 inches, wide on each side of the sheet parting. Its width, however, decreases gradually from the surface sheets downward. In places the sap consists of two parts— an outer dark brownish zone from three-fourths to H inches wide and an inner more yellowish zone from one-fourth to one-half inch wide.