Slate Deposits and Slate Industry of the United States, Issues 275-280 |
Common terms and phrases
aggregate polarization analyses andalusite angles Arvonia biotite black slate calcareous calcite Cambrian Cambrian slate carbonaceous carbonaceous matter carbonate cent chemical chlorite clay cleav cleavage dip cleavage surface cold dilute hydrochloric constituents County crystals deposits dikes dilute hydrochloric acid discoloration east false cleavage fault feet feldspar ferrous ferrous oxide folds fractures Geological graphitic green slate hematite hogback hydrochloric acid inch kaolin Lehigh lenses lime limonite magnesia magnetite matrix of muscovite mica microscope miles mineral muscovite sericite occur Ordovician oxide parallel particles Pawlet Peach Bottom plagioclase planes plicated purple slate pyrite quartz quartzite quartzite beds red slate rhombs ribbons rock roofing slate rutile rutile needles sawn edge schist secondary sediments shale shear zones slate belt Slate Company slate quarries Slatington slaty cleavage slip cleavage sonorous specimen square millimeter structure syncline texture thickness thin section tourmaline U. S. Geol veins Vermont western Vermont
Popular passages
Page 49 - Such an analysis should then be compared with complete analyses of the best slates of like color, and before a final conclusion is reached as to the value of the.slate its microscopic analysis and the results of the tests of its strength, elasticity, porosity, and corrodibility should be considered in connection with its chemical analysis. Merriman concludes from six different kinds of tests applied to each of 24 specimens of...
Page 5 - The term slate, in ordinary usage, denotes a rock which has more or less perfect cleavage, being thus adapted to various commercial uses, and in which the constituent particles, with very few exceptions, can not be distinguished except in thin section under a microscope. In contradistinction a schist is a rock...
Page 47 - The pieces were supported in a horizontal position, upon wooden knife edges 22 inches apart and the loads were applied upon another knife edge placed half way between the supports. This load being applied by means of sand running out of an orifice in a box, at the rate of 70 pounds per minute, the flow being checked by means of an electric attachment the moment rupture took place.
Page 52 - ... effervesce with cold dilute hydrochloric acid, is very sonorous and very fissile. Under the microscope this slate shows a matrix of muscovite (sericite), with a very brilliant aggregate polarization and an unusually fine texture and great homogeneity. Quartz grains are few and not over 0.01 millimeter in diameter. Rutile needles unusually minute. Many opaque particles of irregular shape, some of which are pyrite, others magnetite, and some coaly or graphitic matter. No carbonate. The constituents,...
Page 6 - The common occurrence of angular grains of feldspar and of quartz in slate implies the nearness of shores or land masses of granitic rocks to such deposits. The alternation of beds of slate with beds of quartzite or grit ("ribbons," "hards," altered sandstone) corresponds to the alternation of extremely fine clayey sediments, derived from the waste of granitic land masses, with sandy sediments consisting of coarser material from the same source. The repeated alternation of such fine and coarse sediments...
Page 60 - Company, about one-half mile southwest of Rockmart, and carried on extensive operations with the diamond drill. The intention was to quarry the slate, sell as slate the portions best suited for that use, and utilize the scrap and waste in the manufacture of cement. The quarries from which the limestone is obtained are located one-half mile east of town, near the mill.
Page 118 - Dale the chief constituents of this slate arranged in descending order of abundance appear to be muscovite (sericite), quartz, pyrite, graphite, magnetite, chlorite, calcium carbonate, and accessory rutile and tourmaline.
Page 7 - ... that which pervaded the strata at the depth at which they were buried, such a chemical recombination of the silica, alumina, potash, iron, and water of the feldspar, kaolin, and iron of the shale as to generate new potash mica in amount sufficient to constitute, in the mica slates, over 33 per cent of the resulting slate. This muscovite was formed in scales of infinitesimal thinness and other dimensions and generally of longish, tapering, or ribbonlike outline.
Page 69 - Greenish-gray slate from Mena. In color this resembles the sea-green slate of Vermont. To the unaided eye it has a fine texture, a roughish cleavage surface, and a waxy luster; does not show pyrite on sawn edge, contains very little magnetite; does not effervesce with cold dilute hydrochloric acid, and is somewhat sonorous. Under the microscope it shows a matrix of muscovite (sericite), with a brilliant aggregate polarization and is of very fine texture and homogeneity, but the cleavage is crossed...
Page 74 - ... that consist either of rhodochrosite or chalcedonic quartz inclosing very minute carbonate rhombs and chlorite scales. Sections parallel to the cleavage show these lenses with a more roundish outline. There are also particles of pyrite, tourmaline prisms, rutile needles, and grains of zircon. The chief constituents of this slate, arranged in descending order of abundance, appear to be muscovite (sericite), quartz, chlorite, carbonate, magnetite, rutile. Its color is due to the abundance of chlorite.