Coal Reserves of the United States: A Progress Report, January 1, 1960U.S. Government Printing Office, 1961 - 116 páginas |
Palavras e frases frequentes
anthracite Arizona base bituminous coal Carmel formation chert Chinle formation coalbeds Coconino coking coal Colorado Plateau Colorado River contains County crossbedded deposits Echo Cliffs Echo monocline Entrada sandstone Estimate of known estimated reserves faults feet thick figure fine-grained ft thick fuels grains inches includes Jurassic Kaibab limestone known recoverable reserves ledge Lees Ferry area lenticular lignite locally lower map area Marble Canyon miles million tons millions of short minerals Mines Rept Moenave formation Moenkopi formation mudstone natural gas Navajo Bridge Navajo sandstone original coal reserves original reserves outcrop overburden percent production reddish-brown 10R Reese and Sisler region remaining reserves reserves of coal sand sandstone member semianthracite shale Shinarump member short tons siltstone silty strata subbituminous coal surface Survey Bull Thickness feet Thickness of bed Thousand Pockets Toroweap formation Triassic U.S. Bur U.S. Bureau U.S. Geol U.S. Geological Survey upper uranium Utah Wahweap Creek
Passagens conhecidas
Página 20 - Inferred reserves of coal are reserves for which quantitative estimates are based largely on broad knowledge of the geologic character of the bed or region and for which few measurements of bed thickness are available. The estimates are based on an assumed continuity for which there is geologic evidence.
Página 16 - There are three varieties of coal in the high-volatile C bituminous coal group, namely, Variety 1, agglomerating and nonweathering; Variety 2, agglomerating and weathering; Variety 3, nonagglomerating and nonweathering.
Página 16 - This classification does not include a few coals which have unusual physical and chemical properties and which come within the limits of fixed carbon or BTU of the high-volatile bituminous and sub-bituminous ranks. All of these coals either contain less than 48...
Página 20 - Indicated reserves are reserves for which tonnage is computed partly from specific measurements and partly from projection of visible data for a reasonable distance on geologic evidence.
Página 5 - ... does not provide the data necessary for a modern inventory of reserves. Progress toward full knowledge of the coal reserves of the United States depends, therefore, upon an active program of detailed geologic mapping and exploratory drilling. Such detailed work is in progress on a modest scale by the United States Geological Survey, and by several State agencies.
Página 18 - ... the length of the outcrop. The total area of coal is considered to extend beyond such a semicircle if mine workings or drill holes so indicate ; in which case coal is considered to extend not more than 1 mile beyond the limits of the mine workings.
Página 3 - ... problems as follows: Although coal is abundant and widespread in the United States (Figs. 1 and 8), reserves of coal also have limits. In the extensively mined eastern coal fields, it is becoming increasingly difficult to locate new areas containing thick beds of high-rank and high-quality coal... . Furthermore, a large part of the total reserves of coal in the United States consists of coal of lignite and sub-bituminous ranks, which yield less heat than bituminous.
Página 16 - Dry FC, 92 percent or more and less than 98 percent (dry VM, 8 percent or less and more than 2 percent) Dry FC, 86 percent or more and less than 92 percent (dry VM, 14 percent or less and more than 8 percent) Dry...
Página 108 - ... Geological Survey, Bull. 54, 1948, 176 pp., 8 plates, geologic map and map of quarries, mines and prospects. Furcron, AS, Mineral resource survey of Floyd County, Georgia : Ga. Mineral Newsletter, Vol. XI, No. 1, Spring 1958, pp. 1-5. Georgia Geological Survey, Geologic map of Georgia, 1939. Johnson. VH, Coal deposits on Sand and Lookout Mountains Dade and Walker Counties. Georgia, USGS, 1946 (geological map).
Página 18 - ... even though points of observation are widely spaced. Persistent beds that have been traced around a basin or spur are considered to underlie the area enclosed by the outcrop. Otherwise, the length of outcrop within the thickness limits listed above is considered to establish the presence of coal in a semicircular area having a radius equal to one-half the length of the outcrop.