The Chief Commercial Granites of Massachusetts, New Hampshire and Rhode Island

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U.S. Government Printing Office, 1908 - 228 Seiten
 

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Seite 217 - A microscopic granular structure sometimes characterizing adjacent folds-par 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 33 - ... Mr. WH Weed and the last by Prof. Lester F. Ward, from a number of localities in Cascade County, Montana, largely in the vicinity of the stage station of Geyser and about forty miles southeast of Great Falls. These were turned over to Professor Fontaine for elaboration, and his report is published in Ward's second paper on the "Status of the Mesozoic Floras of the United States...
Seite 219 - SAND STREAKS. Same as sand seams. SAP. Quarrymen's term for ferruginous discoloration along sheet or joint surfaces. SCHIST. A rock made up of flattish particles arranged in rough parallelism, some or all of which have crystallized under pressure. SCHISTOSITY. The quality of being like a schist. SEAM. Quarrymen's term for joint. SECONDARY MINERALS. Minerals whose presence is due to the alteration of the original minerals. SEDIMENTARY. A term designating those rocks that consist of particles deposited...
Seite 40 - The impact of the hammer breaks up the granules on the immediate surface so that the light falling upon it is reflected, instead of absorbed, and the resultant effect upon the eye is that of whiteness. The darker color of a polished surface is due merely to the fact that through careful grinding all these irregularities and reflecting surfaces are removed, the light penetrating the stone is absorbed, and the effect upon the eye is that of a more or less complete absence of light or darkness. Obviously...
Seite 164 - ... the greenish tinge. An estimate of the mineral percentages made by applying the Rosiwal method to a camera lucida drawing of a thin section enlarged 40 diameters yields these results with a mesh of 1 inch and a total linear length of 34 inches.
Seite 27 - India (p. 25), but as it penetrates only to a depth of 40 feet and as sheet structure is known to occur on Crotch Island, Maine, at a depth of 140 feet and at Quincy, Mass., at a depth of 175 feet, it is quite inadequate to account for sheets that are 20 to 30 feet thick and 100 to 175 feet below the surface. 2. In view of the load under which granite was probably formed, as shown by the presence of liquid carbonic acid in its quartz...
Seite 90 - ... the porphyritic feldspars on the rough face is marked. The quarry, opened in 1906, measures about 100 by 35 feet and 5 feet in depth. The sheets, from 1 to 3 feet thick, are horizontal or inclined 15° S. There is but one set of joints, which strikes N. 65° E. and is vertical, and is spaced 5 to 20 feet. The rift is reported as horizontal and the grain as vertical, with N. 20° W. course. Biotitic knots are up to 1.5 inches across. A "shake" structure extends down to 16 inches from the surface.
Seite 219 - ... and of potash feldspar are nearly the same or in which the former exceeds the latter. In ordinary granites the amount of soda-lime feldspar is relatively small. RANDOM STONE. A term applied by quarrymen to quarried blocks of any dimensions. (See definition of dimension stone.) RUT. A quarrymen 's term to designate an obscure microscopic cleavage in granite which greatly facilitates quarrying. RUN. A term used by quarrymen in connection with "rift...
Seite 40 - Merrill0 explains the cause of these contrasts very satisfactorily : The impact of the hammer breaks up the granules on the immediate surface, so that the light falling upon it is reflected, instead of absorbed, and the resultant effect upon the eye is that of whiteness. The darker color of a polished surface is due merely to the fact that, through careful grinding, all these irregularities and reflecting surfaces are removed...
Seite 38 - The subject of weathering of granite is fully treated in the writings of Merrill, Keyes, and Watson." The changes in granite after it has entered into buildings or other constructions are less marked than those in the natural rock, because the blocks are not then traversed by anything analogous to sheet and joint structure, and also because the years of historic time are few compared to those of geologic time. Much has been written on the decay of granite in monuments and buildings.6 Such decay is...

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