Economic Geology

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Page 62 - They are made principally by rail over the international bridges and by lake and sea to the Canadian provinces. Exports are also made by sea to the West Indies, to Central and South America, and elsewhere. The imports are principally from Australia and British Columbia to San Francisco, from Great Britain to the Atlantic and Pacific coasts, and from Nova Scotia to Atlantic coast points.
Page 802 - Ores containing less than 40 per cent manganese or more than 12 per cent silica or 0.225 per cent phosphorus are subject to acceptance or refusal at the buyer's option. Settlements are based on analysis of sample dried at 212 F., the percentage of moisture in the sample as taken being deducted from the weight.
Page 31 - Dry storage has no advantage over storage in the open except with high sulphur coals, where the disintegrating effect of sulphur in the process of oxidation facilitates the escape of hydrocarbons or the oxidation of the same.
Page x - Calif 410 131. Ideal section across a river valley, showing the position of ground water and the undulations of the water table with reference to the surface of the ground and bed rock 416 132.
Page 284 - The phosphate forms beds interstratified with limestones and shales, the series in all cases having been much disturbed by folding and faulting. Those of the Georgetown area have been involved in the great Bannock thrust fault.1 In hand specimens the phosphate is seen to be dense, with an oolitic texture. It is dark brown when fresh, but becomes bluish white on weathering. Under the microscope it shows an isotropic mineral, possibly collophanite, and a doubly refracting phosphate, possibly quercyite....
Page 390 - Mineral Resources of the United States published annually by the United States Geological Survey.
Page 325 - This addition is not as an adulterant, as was the case a few years ago, for it is now appreciated that the addition of barytes makes a white pigment more permanent, less likely to be attacked by acids, and freer from discoloration than when white lead is used alone.
Page 58 - Hennepin, who in 1679 recorded the site of a " cole mine " on the Illinois River near the present city of Ottawa, Illinois, but the first actual mining appears to have occurred in the Richmond basin, Virginia, about seventy years later. The first records of production are i The Coal Resources of the World.
Page 833 - ... subjected. This left them in the right physical condition to be readily jointed and fissured by the contraction of the diabase. After the deposition of the cobalt-nickel arsenides, which seem to be among the first minerals deposited, the veins appear to have been slightly disturbed, giving rise to cracks and openings in which the silver and later minerals were deposited. Veins which escaped this later, slight disturbance contain little or no silver.
Page 295 - XXVI, Fig. 2), the raw material quarried for scythestones is a fine-grained, thinly laminated, micaceous sandstone, whose quartz grains occur in definite layers, separated by thin layers of mica flakes. Those portions of the rock in. which the quartz grains are coarse or irregularly disposed, as well as argillaceous portions, are unfit for abrasive purposes.1 The novaculite quarried in Garland and Saline counties, Arkansas (17), represents a unique type, much prized for high-grade 1 Min.

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