The Granites of Vermont

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U.S. Government Printing Office, 1909 - 138 Seiten
 

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Seite 132 - A term used by quarrymen in connection with "rift," apparently to denote the course of the deflection of the rift due to gravity, strain, or other not yet understood cause.
Seite 32 - 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 129 - A preliminary report on a part of the granites and- gneisses of Georgia : Georgia Geol.
Seite 7 - ... the position of the beds in the Canton-Avon quadrangles. The Survey has received a number of requests for this information, and since wells are to be drilled, it would be wise to test first the areas which have one factor — namely, favorable geological structure, determined in advance of drilling. The field work upon which this report is based was done in 1914 as part of the regular program of the State Geological Survey in cooperation with (91) the United States Geological Survey.
Seite 32 - ... biotite (black mica) some of it chloritized; and muscovite (white mica). Accessory minerals are very little magnetite, apatite, zircon, and rutile.
Seite 132 - 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 under water. SEGREGATION. The scientific term for "knot;" a collection of material separated from other material.
Seite 47 - Montpelier (see fig. 1), and the Barre quarries are 3 miles farther southeast, near the southeast corner of the township of Barre, and a few of them are in Williamstown, in Orange County, which adjoins Barre on the south. The city of Barre lies on Stephens Brook, a tributary of the Winooski, which empties into Lake Champlain. About half a mile southMillstone Hill WeBsterville Jail River W.
Seite 48 - ... long by 1| wide, surrounded by slate and schist. Its representation on the state geologic map of 1861 is not far different. The writer's time was too short to enable him to trace the boundaries of the granite and schist, nor was a map suitable for such purpose available. Finlay represents a schist tongue crossing Millstone Hill diagonally from northwest to southeast, and Cobble Hill as all granite, but the writer found schist on the north side of the top of the Cobble, without, however, determining...
Seite 36 - ... operator of the quarry states that the rift is horizontal in the granite but vertical in the adjacent diorite. The granite (specimens, D, XXVIII, 47, a, b), "light Sunapee," is a biotite-muscovite granite of a light gray, slightly bluish color and very fine to fine texture, with feldspars up to 0.15 inch and mica to 0.1 inch. Its constituents, in descending order of abundance, are: Colorless, clear potash feldspar (microcline and orthoclase, the latter with hairlike crystals probably of rutile,...
Seite 77 - Muscovite apparently occurs in two forms, one corresponding to the biotite, as seemingly primary, and the other in small flakes in the orthoclase, and clearly a secondary mineral. Accessory constituents are oligoclase, albite (?), titanite (sphene), and apatite. There is an almost total absence of magnetite or other iron ore. Biotite is slightly changed to green, and probably yields chlorite in some samples. The orthoclase gives way to an aggregate of fine muscovite leaves, also varying much in different...

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