The Green Schists and Associated Granites and Porphyries of Rhode Island

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U.S. Government Printing Office, 1907 - 74 стор.
 

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Сторінка 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.
Сторінка 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.
Сторінка 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.
Сторінка 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....
Сторінка 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.
Сторінка 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.
Сторінка 206 - B 312. The interaction between minerals and water solutions, with special reference to geologic phenomena, by EC Sullivan.
Сторінка 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.

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