Contributions to Economic Geology, 1907U.S. Government Printing Office, 1908 - Geology, Economic |
Common terms and phrases
amount andesite anticline antimony average beds biotite breccia Bulletin calcite canyon cement cent Cerbat chalcopyrite Chattanooga shale chert chloritic clay coal Colorado considerable consists contains copper deposits country rock County Creek crystals depth developed dikes drift east exposed extends fault feet thick feldspar fissure formation fractured galena geology gneiss Gold Road granite gravel Gulch Hill igneous inches intrusive iron limestone locally located lode material mica miles mill mine.-The Mineral Resources U. S. mining district molybdenite monazite Mountain northeast northwest occur ounces outcrop oxidized pegmatite places porphyry portion pre-Cambrian principal probably production prospects pyrite quadrangle quarry quartz quartzite range region reported Rept rhyolite ridge River sand sandstone schists seams shaft shale siliceous silver slates slope southwest sphalerite stibnite stone strata sulphide surface Survey tion tunnel U. S. Geol upper valley vein vicinity width zinc zone
Popular passages
Page 319 - KIMBALL, JP Geological relations and genesis of the specular iron ores of Santiago de Cuba: Am.
Page 280 - ... down in some cases. The partial concentration of monazite in the top layer of soil is caused by the washing away of the clay and other light decomposition products of the rock. The supply of monazite in the stream gravels in favorable areas is often replenished by the wash from the hillside soils during rains, especially where the hills have any considerable slope and the land is cultivated. Under such conditions the streamgravels are often worked two or more times in a year.
Page 425 - SHALER, NS, WOODWORTH, JB, and MARBUT, CF The glacial brick clays of Rhode Island and southeastern Massachusetts. In Seventeenth Ann. Rept., pt. 1, pp. 957-1004. 1896.
Page 280 - Such deposits have generally soon been lost or grown poor, probably due to the fact that the miners have cut through the richer bed or failed to follow it in the direction of its extension. The occurrence of monazite in saprolite is merely an altered phase of the occurrence in hard-rock formations. With the exception of the plant mentioned above, all the monazite mined in the Carolinas has been...
Page 279 - The quartz grains of the granite remain as sand mixed through a clayey matrix. This quartz sand is almost everywhere to be seen at the immediate surface, from which the clays have been washed by rains. Where Carolina gneiss and granite are intimately associated, or where pegmatization has been extensive in a body of Carolina gneiss, there results a sandy soil, characteristic of granite, through which are scattered pebb,les of hematite and ferruginous cyanite, characteristic of the Carolina gneiss....
Page 279 - ... dark reddish-brown or chocolate-colored clayey soil on decomposition. Black stains of manganese are associated with many of the soils derived from hornblendic rocks. A clew to the nature of the...
Page 14 - Geography and geology of a portion of southwestern Wyoming, with special reference to coal and oil, by AC Veatch.
Page 283 - Graphite occurs as plates and laths, in general lying parallel to the banding of the rock. Some of it is interbanded and even interleaved with biotite ; elsewhere the plates are turned across the foliation. In one section a lath of graphite was observed inclosed in quartz which filled a fracture across the foliation of a biotite crystal. Monazite occurs in contact with the various minerals of the sectoin, though it is more commonly surrounded by or included in grains of biotite and quartz.
Page 116 - WEEKS, FB Geology and mineral resources of the Osceola mining district. White Pine County, Nev. In Bulletin No.
Page 372 - ... oil. Of course the proportions of products will be somewhat different on a refining scale (1,000 barrels) — probably larger, rather than smaller, than is given on the small scale. This petroleum is different from any of the numerous specimens that I have previously examined from Wyoming. A large amount of very light gasoline can be separated by strong cooling. With respect to the large proportion of gasoline and of burning oil, also of paraffin, this petroleum is one of the most valuable that...