Bulletin - United States Geological Survey, Issue 620

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Page 353 - California, and are of the compound, unsymmetrical type whose different parts are thought to be due to differentiation processes rather than to multiple injections of material into reopened fissures. The upper portion of the dike is locally known as the "top rock" (nos. 89549, 89550) and is a mixture of a coarse, granular aggregate of quartz and feldspar and of a graphic pegmatite. No gem stones are found in this "top rock.
Page 289 - Hoffer, give the run of gold in colors for the first 12 feet of gravel in two different places. Colors of gold in upper gravel at Pine Bar diggings. The tests were made on one-thirtieth cubic foot of gravel carefully measured and the results per cubic foot were obtained by multiplying these values by 30. About 1,000 to 1,200 colors make 1 cent value. Thus it will be observed that this 8 feet of gravel, both tests being averaged, yields from 12 to 14 cents a cubic yard. Including the upper 8 feet,...
Page 56 - ... brecciation of the country rock. The gangue is highly siliceous and is cut by small stringers of calcite and siderite, the former occurring in places in conspicuous quantities, but being entirely absent in the croppings of the vein, where silica with a little black oxide of manganese forms the ledge. In width the vein varies from a few inches to several feet; parallel breccia planes of small magnitude, which accompany the main fault in places, tend to widen the deposit. The ore shoot in the property...
Page 267 - Eight tons of the calcined mineral is then added in portions and well stirred. After the whole has been added the liquid is left for two hours then evaporated to 38 B. and treated with 2.7 tons potassium sulphate. The process up to this point occupies 10 hours ; after a further period of 13 hours the clear liquid is decanted off; its density should not exceed 42 B.
Page 212 - Masses of unchanged sulphides occur, and especially galenite in considerable quantity in some of them ; but the process of oxidation has prevailed very extensively, so that the ochraceous character of the ores is the striking feature of most of the mines in this range. The great chamber of the Emma Mine, which is an ovoidal cavity measuring, so far as explored, about 110 feet vertical by about 80 by 110 feet transverse, was found to be filled almost exclusively with epigene species, the product of...
Page 264 - On leaching the residue with water the potassium sulphate is dissolved, leaving the insoluble aluminum oxide behind. The average amount of potassium sulphate leached from the ignited mineral powder is 17.9 per cent of the original material used. As the coarsely crystallized alunite was found to contain 19.4 per cent of potassium sulphate, 92 per cent of the total potash present was obtained by simple ignition and subsequent leaching. It is worth noting that, according to the laboratory experiments,...
Page 272 - Schultz, AR, Geology and geography of a portion of Lincoln County, Wyo. : US Geol. Survey Bull. 543, 1914.
Page 105 - The finished product obtained by this process (the Goltra process') is excellently adapted for use in the blast furnace. The free and combined water are completely, and the clay, -sand, etc., almost completely, removed. The sulphur, except in the case of some magnetic concentrates, is eliminated. The 'physical nature of the ore is greatly improved, particularly in respect to its porosity and easy reducibility in the blast furnace.
Page 214 - ... in thickness, often less. They are quite abundant in this association, no piece of the calamine which I have seen being without them. They sometimes, but rarely, penetrate through the globules of the calamine so as to show themselves on the upper surface of that species. But the calamine has obviously formed...
Page 237 - BUTLER, BS, and GALE, HS, Alunite — a newly discovered deposit near Marysvale, Utah: US Geol.

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