Report of the State Geologist on the Mineral Industries and Geology of Vermont, Band 7

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Seite 191 - SERICITE. A more or less fibrous form of muscovite (potash mica), often resulting from the alteration of feldspar. SHAKES. Quarrymen's term to designate a somewhat minute close-joint structure, which forms along the sheet surface as a result of weathering. SHEET QUARRY. A quarry in which the granite lies in sheets, crossed by wide-spaced steep joints. SLICKENSIDES. The polished and grooved faces of a joint or bed caused by motion and friction. SPECIFIC GRAVITY. The weight of a rock or mineral compared...
Seite 191 - 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 under water. SEGREGATION. The...
Seite 189 - GLOSSARY OF SCIENTIFIC AND QUARRY TERMS. ACCESSORY MINERALS in granite are original constituents of the rock, found only in small, often only in microscopic quantity. ACIDIC.
Seite 189 - QUARRY. One in which the joints are either so close or so irregular that no very large blocks of stone can be quarried. CHANNEL. A narrow artificial incision across a mass of rock, which, in the case of a granite sheet, is made either by a series of contiguous drill holes or by blasting a series of holes arranged in zigzag order. ^ CLEAVAGE, when applied to a mineral, designates a structure consequent upon the geometrical arrangement of its molecules at the time of its crystallization. CLOSE-JOINTED....
Seite 337 - ... a square being a sufficient number of pieces of slate of any size to cover 100 square feet of roof, with allowance generally for a 3-inch lap. The size of the pieces of slate making up a square ranges from 7 by 9 inches to 16 by 24 inches, and the number of pieces in a square ranges from 85 to 686, according to the size of the pieces. The ordinary thickness of a piece is from one-eighth to three-sixteenths of an inch, and the approximate weight per square is about 650 pounds. The slate is generally...
Seite 97 - ... biotite (black mica) some of it chloritized; and muscovite (white mica). Accessory minerals are very little magnetite, apatite, zircon, and rutile.
Seite 112 - ... represented: (1) The schist, a metamorphosed marine argillaceous and calcareous sediment of unknown thickness, underlying the city and surrounding the granite area; (2) the granite, of igneous origin, intruded in the schist and forming two domes, 2 miles apart, with an intervening depression, which in consequence of the erosion of the schist now project through it; (3) certain dark basic dikes of later date cutting the granite and the schist also; (4) finally, masses of sand, clay, and bowlders,...
Seite 103 - ... inch. Its constituents, in descending order of abundance, are: Very light smoky quartz...
Seite 112 - ... 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 its...
Seite 132 - The product is used for rough and hammered face and carved monuments. The following specimen monuments combine the product of this quarry with that of the firm's dark quarry described on page 85: Ohio and Iowa state soldiers' monuments, Chattanooga, Tenn.; Governor Curtin monument, Bellefonte, Pa.; state soldiers...

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