The Proceedings of the Iowa Academy of Science, Volum 2

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Iowa Academy of Science, 1895
 

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Pàgina 38 - ... the surface, as the mineral-bearing rock did not reach a greater depth. To separate the mineral great heaps were constructed with wood intermingled with the rock. These were fired, and after the fire had done its work the heat was found to have been insufficient to melt the galena. It had only broken the rock into small pieces. Then this was washed and the mineral was separated. The latter was smelted in a furnace located at the mouth of Mineral Creek. During the two years that the mines were...
Pàgina 36 - While these north-and-south crevices are not uncommon in the State, they are usually of limited extent and do not contain large bodies of ore. But here the sheet is an extensive one and does not yet show any signs of giving out. The mine was discovered in January. 1891, by Captain Turner, who had reached the conclusion that lead occurred in the Oneota and had done considerable prospecting at various points. The location is on a hillside that slopes to the north and east. While the general...
Pàgina 38 - Peter sandstone. Mineral Creek has cut its valley through this sandstone and well down into the underlying limestone, which here has an exposed thickness of more than 100 feet. This latter rock shows evidence of considerable disturbance, being more or less brecciated, and has been recemented by siliceous material. It is full of cherty, or flinty, matter and is very impure. The mines were on a hillside and were worked by means of short drifts. Instead of being in crevices the ore occurred scattered...
Pàgina 37 - The bulk of the ore is, however, about 50 feet above the sandstone. The sheet of lead is either imbedded in the crevice clay or fills the entire space between the rock walls. Where it extends south under the hill and has been little exposed to weathering agencies, the sides of the fissure have not undergone decomposition and the sheet is in contact with the rock. In other places where examined an inch or so of clay was found between it and the limestone, the crevice in this case being from 6 to 8...
Pàgina 175 - The mode of formation of the topaz and garnet is not fully determinable, but it is evident that they are not secondary products, like zeolites, but primary, and produced by sublimation or crystallization from presumably heated solutions, contemporaneous or nearly so with the final consolidation of the rock.
Pàgina 37 - ... 1891, by Captain Turner, who had reached the conclusion that lead occurred in the Oneota and had done considerable prospecting at various points. The location is on a hillside that slopes to the north and east. While the general direction of the crevice is nearly north and south (S. 10° E.), its course is not straight, but zigzags back and forth within certain limits, so that a shaft sunk on a general course of the fissure may be several feet out of the way.
Pàgina 65 - From a careful consideralion of the whole of the results, it would perhaps not be unreasonable to suggest that, when a soil is found to contain as little as about...
Pàgina 126 - A Catalogue of the Native and Naturalized Plants of the City of Buffalo and Its Vicinity.
Pàgina 37 - While the general direction of the crevice is nearly north and south (S. 10° E.), its course is not straight, but zigzags back and forth within certain limits, so that a shaft sunk on a general course of the fissure may be several feet out of the way. The sheet has been followed 1,000 feet and its limits have not been reached either to the north or south. At the north end of the present workings the fissure is interrupted by a ravine and the sheet thus outcrops. There is reason for supposing that...
Pàgina 107 - A new weed that It steadily gaining ground, traveling eastward and possibly southward . It Is a candidate for the same situations the large ragweed prefers— the edges of fields, and along roadsides and streets, but especially about barns. If circumstances are unfavorable, It can blossom when only a few Inches high, while under more fortunate conditions it reaches much above one's head. It closely resembles cocklebur when young, but as It grows larger has more the appearance of the common sunflower,...

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