Annual Report for ... with Accompanying Papers, Band 8Published for the Iowa Geological Survey, 1898 |
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Athyris subtilita beds blue bluff bowlder clay Bremen township brick Buchanan county Buchanan gravels building stones calcareous cement chert coal measures color Dallas county Decatur county Delaware county deposits depth Devonian dolomite drainage east Elk creek Elk township erosion exposed exposures feet ferruginous Fire clay formation fossiliferous fossils G Rep Grand river granite gray horizon inches Iowa Iowa Geol Iowan ice Kansan drift layers ledges lime loess Maquoketa material Meter miles mill Milo township Moines Niagara limestone northeast occur outcrops oxidized pennatus Pentamerus Plate Pleistocene Plymouth county points portion prairie quarry stone quarter of section Raccoon river Redfield region rock sand Sandstone sandy shales shows Sioux slopes soil South Fork township southeast southwest quarter Spirifer strata stream surface Surv terrace tests thickness thin tion topography Union township upland upper usually valley vein Wapsipinicon weathered Winterset Wisconsin yellow
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Seite 343 - ... 3. Alkalies, so far as indicated by the behavior of .soda, are of no value in promoting the combination of lime and silica, and probably play no part in the formation of cement. "4. Magnesia, though possessing marked hydraulic properties when ignited alone, yields no hydraulic products when heated with silica, alumina, or clay, and probably plays no part in the formation of cement. It is incapable of replacing lime in cement mixtures, the composition of which should be calculated on the basis...
Seite 172 - The rock is granular, vesicular, much pitted by weathering where exposed, rather evenly-bedded; beds are horizontal and vary from a few inches to more than a foot in thickness. The...
Seite 343 - From this formula it may be calculated that the correct proportion of lime, by weight, in Portland cement, is 2.8 times the silica plus 1.1 times the alumina. "2. Iron oxide combines with lime at a high heat, and acts like alumina in promoting the combination of silica...
Seite 343 - Portland cement, is 2.8 times the silica plus 1.1 times the alumina. 2. Iron oxide combines with lime at a high heat, and acts like alumina in promoting the combination of silica and lime. For practical purposes, however, the presence of iron oxide in a clay need not be considered in calculating the proportion of lime required.
Seite 205 - Madison township, and there are exposures on the township fine between section 18 of Madison township and 13 of Buffalo. The limestone here occurs in stony knobs or prominences and affords a section twelve or fifteen feet in thickness. The beds are quite regular, from two to six inches in thickness, and they have been quarried in a small way at one or two points, and in at least one locality they have been used in the manufacture of lime. The drift is very thin on all the low, rounded hills of the...
Seite 100 - they were in large flocks containing both species in the proportion of two of the former to one of the latter " (the present)
Seite 382 - ... some part of the rock mapped as microgranite, but can not well be separated without extensive microscopic work. Even at the East Greenwich quarry some slides are half micrographic in texture. It is a fine, evengrained rock, distinctly granular with the lens, bluish white, weathering pale fawn color. Under the microscope it is seen to be made up of rather large, rounded, or interlocking grains of orthoclase or microcline with exceedingly fine twinning structure, each grain filled with vermiform...
Seite 343 - Iron oxide (Fe203) combines with lime at a high heat, and acts like alumina in promoting the combination of silica and lime. For practical purposes, however, the presence of iron oxide in a clay need not be considered in calculating the proportion of lime required...
Seite 86 - At one point a shaft has been sunk to a depth of 100 feet and a three-foot vein of coal worked for several years.
Seite 107 - Marsh gas, the principal constitutent, is a simple compound of carbon and hydrogen in the proportions of 75 per cent of the former to 25 per cent of the latter. The natural gas...