Economic Geology, Volume 13Economic Geology Publishing Company, 1918 - Geology |
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acid amount anticlinal appears basins beds bornite calcite carbon carnotite cavities cement cent chalcocite chalcopyrite copper country rock covellite crystals deposits depth diabase dikes discussion district dolomite domes drilling ECON ECONOMIC GEOLOGY enrichment Eocene epidote erosion evidence fault feet field fissures formation fractures gabbro gangue Geological Survey geologists gold chloride grains granite gravel heat hematite hydroxide igneous rocks ilmenite important inches intergrowth intrusion Jour lamellæ limestone magma magnetic magnetite material metal metamorphism miles mineral Mines Miocene molybdenite observed occur oil and gas origin outcrops oxide pegmatite peneplain Petroleum Plate porosity precipitated present pressure probably production pyrite quartz reefs region replacement road sand sandstone sedimentary sediments shale silicate silver solution specimen stone strata structure Suan Sudbury sulphides sulphur surface Survey Bull temperature tests Tetrahedrite theory tion U. S. Geol valleys vanadium veins writer zone
Popular passages
Page 595 - Antimony, arsenic, ball clay, bismuth, bromine, cerium, chalk, chromium, cobalt, corundum, emery, fluorspar, ferrosilicon, fullers' earth, 'graphite, grinding pebbles, iridium, kaolin, magnesite, manganese, mercury, mica, molybdenum, osmium, sodium, platinum, palladium, paper clay, phosphorus, potassium, pyrites, radium, sulphur, thorium, tin, titanium, tungsten, uranium, vanadium, and zirconium, as the President may, from...
Page 452 - To suppose for an instant that the orderly rectilinear mode of occurrence of the saline domes is merely the work of chance is extreme folly .... clearly, the varied wrenching and warping suffered by the rocks of this great delta region have given rise — and naturally so — to structural features more or less parallel to the shores of the Old Cretaceous terranes to the northeast and northwest. In the opinion of the writer all the saline domes are located along lines of fracture in the deep-lying...
Page 196 - ... the extent to which the strata above or below the gas-sand are cracked ; (c) the dip of the gas-sand and the position of the anticlines and synclines...
Page 195 - ... three quarter millions of barrels of petroleum. The total produce of the great Pennsylvania oilregion for the ten years from 1860 to 1870 is estimated at twenty-eight millions of barrels of petroleum, or less than would be contained in four square miles of the oil-bearing limestone band of Chicago. It is not here the place to insist upon the geological conditions which favor the liberation of a portion of the oil from such rocks, and its accumulation in fissures along certain anticlinal lines...
Page 506 - Intelligence, and whose function shall be the securing, classifying, and disseminating of scientific, technical, and industrial research information, especially relating to war problems, and the interchange of such information between the Allies in Europe and the United States.
Page 488 - ... found to carry oil. The oilfields are found in the areas of Tertiary sediments distributed along the sea-coast, excepting in Hokkaido, where the oil district of the Ishikari Valley is near the centre of the island. A probable oilfield has been reported also in Saghalien. The Echigo and Akita districts both occur in the extensive area of Tertiary sediments which occur almost continuously along the west coast of Honshu, the main island of Japan, bordering the Japan Sea, extending from Shinano Province...
Page 459 - As the region lies along a heavily loaded sea coast, the nature of the lateral' thrust is not difficult to understand. The fact that the surface beds are undisturbed, except immediately around the salt plugs, is explained by the nature of the section — a series of indurated and rigid formations overlain by a great thickness of relatively yielding and plastic sediments. Indirect evidence of the origin of the plugs is also afforded by their identity in structure and composition with the European...
Page 146 - Here you may make tunnels or burrow mines.' I saw on the walls of the room vertical sections of the country, and inquiry brought the answer that they were for the study of underground watersystems; for the rise and fall of such might interfere with tunnels and mines, and so knowledge of them is necessary. Never have I spent a more interesting hour. It was said that one reason for the great success of the British operations at the Messines Ridge, when fifty or more mines were exploded, was the skill...
Page 187 - Structural Relations of the Pre-Cambrian and Paleozoic Rocks North of the Ottawa and St. Lawrence Valleys,
Page 198 - ... formations has come by migration. The main mass of the outcrop of the formation in this region is in the Sierra Madres, the front range of which passes points respectively 28 miles west and 16 miles south of the Furbero field. The formation has not yet been encountered by wells drilled in this region, but it is very probable that the oil of this field originated in the Tamasopo and was forced upward by hydraulic and gas pressures, along a channel formed by the broken and metamorphosed zone of...