The Granites of MaineU.S. Government Printing Office, 1907 - 202 Seiten |
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20 feet accessory magnetite apatite aplite Biddeford biotite granite biotite scales black granites black mica biotite calcite chlorite coarse color County Crotch Island crystals derricks descending order diabase dike diorite east epidote even-grained texture feet deep feet in depth feet thick forms a heading gabbro Geological Survey grain Granite Company granite quarries granite specimen gray hoisting engines hornblende inches thick kaolin knots magnetite Maine granites mass microcline microscopic miles minerals monuments Mount Desert Mount Waldo muscovite Norridgewock opened Operator order of abundance orthoclase particles paving blocks pegmatite pinkish plagioclase plant consists polish porphyritic potash feldspar microcline potash feldspar orthoclase pumping pyrite quarry quartz monzonite recur at intervals Redbeach rift is horizontal rift is vertical Rock structure schist sheet structure side smoky quartz soda-lime feldspar oligoclase steam drills Sullivan surface titanite town Transportation is effected Vertical joints strike Vinalhaven Waldoboro wharf white mica York zircon
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Seite 180 - 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 32 - An interesting feature of both headings and joints shown in some of the deeper quarries at Quincy, Mass., which may lx> found in Maine as the quarries are deepened, is their vertical discontinuity. A heading occurring at the surface may disappear below, or a heading may abruptly appear a hundred feet below the surface and continue downward. Headings are not easily accounted for. They may...
Seite 37 - ... traverse, but they represent a later stage of igneous activity. The fissures they fill were the result of various tensional strains or contractions, possibly consequent upon the cooling of the granite. In color these dikes vary from bluish gray to light and dark reddish. The texture of some aplites is so fine that the mineral particles can not be distinguished with the unaided eye ; that of others is so coarse that the feldspar and mica may be thus detected. Under the microscope the dimensions...
Seite 199 - Preliminary report on the operations of the fuel-testing plant of the United States Geological Survey at St. Louis, Mo., 1905, by JA Holmes. 1906.
Seite 24 - That this structure is not the result of the original stratification of the rock is evident from a study of the phenomena, which do not indicate anything like anticlinal or synclinal axes, or any irregular folding. The curves are arranged strictly with reference to the surface of the masses of rock, showing clearly that they must have been produced by the contraction of the material while cooling or solidifying.
Seite 16 - Elasticity," and found that slabs of gaged lengths of 20 inches in passing from a cold-water bath at 32° F. through a hot-water bath at 212° F., and back again to cold water at 32° F., expanded from 0.0017 to 0.0059 inch, averaging 0.0040 inch. Porosity. — Granite, contains and absorbs water, which is held in microscopic spaces both within and between its constituent minerals.
Seite 9 - 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. In granite, however, the mass has cooled slowly enough to permit the complete crystallization of the originally molten glasslike matter, and no unarranged molecules remain. The overlying rock mass which furnished so large a part of the pressure required to form...
Seite 32 - That many joints are due to compressive or torsional strain, and that every such strain resolves itself into two components, resulting in two sets of joints that intersect at an angle of about 90°, each forming an angle of about 45° with the direction of the strain, are facts now generally recognized. Crosby 6 has suggested that torsional strains may have been supplemented by vibratory ones in causing joints. Becker...
Seite 17 - The most notable change was that "when struck with a hammer or scratched with a knife they emitted the sound peculiar to a burnt brick." Cutting c applied a fire test to granites from eighteen quarries in Maine, Maryland, Massachusetts, Minnesota, New Hampshire, Vermont, and Virginia, with the result that after saturation they all stood a temperature of 500° F. without damage, but showed the first appearance of injury at 700°-800° and were rendered worth less at 900°-1,000°.