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At least 415 records · Page 23Linked to original sources
USGS1972

Hydrograph simulation models of the Hillsborough and Alafia Rivers, Florida: a preliminary report

Mathematical (digital) models that simulate flood hydrographs from rainfall records have been developed for the following gaging stations in the Hillsborough and Alafia River basins of west-central Florida: Hillsborough River near Tampa, Alafia River at Lithia, and north Prong Alafia River near Keysville. These models, which were developed from historical streamflow and and rainfall records, are based on rainfall-runoff and unit-hydrograph procedures involving an arbitrary separation of the flood hydrograph. These models assume the flood hydrograph to be composed of only two flow components, direct (storm) runoff, and base flow. Expressions describing these two flow components are derived from streamflow and rainfall records and are combined analytically to form algorithms (models), which are programmed for processing on a digital computing system. Most Hillsborough and Alafia River flood discharges can be simulated with expected relative errors less than or equal to 30 percent and flood peaks can be simulated with average relative errors less than 15 percent. Because of the inadequate rainfall network that is used in obtaining input data for the North Prong Alafia River model, simulated peaks are frequently in error by more than 40 percent, particularly for storms having highly variable areal rainfall distribution. Simulation errors are the result of rainfall sample errors and, to a lesser extent, model inadequacy. Data errors associated with the determination of mean basin precipitation are the result of the small number and poor areal distribution of rainfall stations available for use in the study. Model inadequacy, however, is attributed to the basic underlying theory, particularly the rainfall-runoff relation. These models broaden and enhance existing water-management capabilities within these basins by allowing the establishment and implementation of programs providing for continued development in these areas. Specifically, the models serve not only as a basis for forecasting floods, but also for simulating hydrologic information needed in flood-plain mapping and delineating and evaluating alternative flood control and abatement plans.

Florida↗
USGS1972

Preliminary report on the geology and field petrology at the Apollo 16 landing site

The Apollo 16 mission was especially notable in the continuing program of manned exploration of the Moon. It accomplished the first landing in the lunar highlands and the crew successfully explored and sampled a kind of terrane never before visited on -the lunar surface. As John Young put it when he first stepped onto the lunar surface "There you are, our mysterious and unknown Descartes highland plains, Apollo 16 is going to change your image." We are confident that the descriptions by the crew and the returned samples and photographs will, in time, permit us to extrapolate the geologic environment found here to many other similar areas throughout the highlands. The geologic diversity and significance of the site, the extended traverse capability provided by three EVAs and the Lunar Roving Vehicle, the real time television coverage of the site and of crew activities, and especially, the outstanding performance of the astronaut crew contributed to an exceedingly successful mission.

Open-File Report↗
USGS1972

A geochemical study of the Rio Pantanos area, Department of Antioquia, Colombia preliminary report

Geochemical sampling in the Western Cordillera has delineated an 18 km 2 area anomalous in copper, molybdenum, and silver. Highly anomalous metal contents are found in stream sediment, soil, and outcrop samples collected within this area. The area is underlain by intrusive granodiorite to quartz diorite that has porphyritic and granitoid phases. Most of the outcrop samples contain disseminated pyrite, chalcopyrite, and bornite. A geochemical reconnaissance sampling program in the Western Cordillera, formulated by Andros Jimeno V., Director, Instituto National de Investigaciones Geologico-Mineras (INGEOMINAS), and Earl M. Irving, U. S. Geological Survey (USGS) Chief of Party in Colombia, was carried out from 1969 to 1971 by geologists of the INGEOMINAS office in Medellin. This work was part of a cooperative program of INGEOMINAS and the USGS sponsored by the Government of Colombia and the Agency for International Development, U. S. Department of State. Seventeen generally east-trending traverses were completed across the Western Cordillera. These traverses, generally paralleling major drainages, cross the range at intervals of 10 to 30 km.

Open-File Report↗
USGS1973

Preliminary report on land-surface subsidence in the area of Burnett, Scott, and Crystal Bays near Baytown, Texas

Removal of water, oil, and gas from the subsurface in Harris County has caused declines in fluid pressures which in turn have resulted in subsidence of the land surface. One critical area of subsidence is in the area of Burnett, Scott, and Crystal Bays near Baytown. Much of this area is now subject to inundation by high tides. Production of oil and gas from the Goose Creek Field at the southern edge of Baytown had caused as much as 3.25 feet of subsidence by 1925. The subsidence bowl is restricted to the area of production and has not extended to the area of Burnett, Scott, and Crystal Bays. Withdrawals of water from large-capacity industrial wells, which resulted in declines in artesian pressure, began about 1918; as much as 250 feet of water-pressure decline has occurred in the Evangeline aquifer, Significant subsidence of the land surface probably began about 1920 or later. Possibly as much as 7.5 feet of subsidence had occurred in the area by 1971. The study of subsidence in the area of the three bays included the collection of undisturbed clay samples for laboratory analyses, collection of water-level records, and installation and monitoring of pressure transducers in clays and of observation wells in sands. Probable future subsidence was calculated for two loading situations. Case I provided that the artesian pressure in both the Alta Loma Sand of Rose (1943) and Evangeline aquifer would continue to decline at a rate of 6 feet per year until 1980 and then cease. Case II provided that artesian pressure in the Alta Loma Sand would continue to decline at a rate of about 6 feet per year until about 1995, when the potentiometric head would reach the top of the Alta Loma Sand. The artesian pressure in the Evangeline aquifer would also decline about 6 feet per year until 1995. The ultimate subsidence expected for the assumed conditions of case I and case II is 11.2 feet and 14.5 feet, respectively. However, only 1.8 feet of subsidence below present land surface would occur if artesian pressures were maintained at their present levels. To halt subsidence in the near future, artesian pressure must be increased. The most logical method of increasing artesian pressure is by decreasing pumpage rather than repressurization by artificial recharge.

Texas↗
USGS1974

Preliminary report on the geology of the Solok Quadrangle, West Sumatra

This report is a brief description of the geology of the Solok quadrangle in West Sumatra. It is based on work done by the writer from April 27 to October 14, 1971, as part of the U. S. Geological Survey (USGS) Cooperative Project with the Geological Survey of Indonesia (GSI). The project is sponsored by the Government of Indonesia and the Agency for International Development, U. S. Department of State, and staffed by personnel of the USGS and counterparts of GSI.

Solok Quadrangle, West Sumatra↗
USGS1974

A preliminary report on a zone containing thick lignite beds, Denver Basin, Colorado

A zone of lignite beds of Paleocene age in the Denver Formation (Upper Cretaceous and Paleocene) lies about 800-1,500 feet above the well-known and extensively mined coal beds of the Laramie Formation (Upper Cretaceous). The zone is a few hundred to as much as 500 feet thick. Where lignite beds lie within 1,000 feet of the surface, this zone underlies an area about 30 miles wide by about 75 miles long, stretching from just northeast of Denver to several miles south of Calhan. Fifteen mines were operated at various periods between 1874 and 1940 and probably produced a total of less than 100,000 tons of lignite, mostly for local use. From 1874 to 1974, several geologists have reported on this lignite zone or the enclosing beds, but no detailed reports have been written except for one by this writer. Drill holes are the main source of geologic data, owing to poor exposure. There are generally about 3 to 6 lignite beds, and they are mostly about 15 or 20 to a few tens of feet apart. Most or all beds typically contain numerous non-coal partings from a fraction of an inch to several inches thick, so that thickness of lignite beds should be stated as gross thickness and as net lignite thickness; net lignite thickness is generally from 70 to 90 percent of gross thickness. Many partings are composed of kaolin, but others are composed of other clay minerals, siltstone, and sandstone. The lignite beds range generally from 1 or 2 to several feet thick, and some are as much as 10-25 feet thick; the thickest known bed has a maximum thickness of 54.5 feet, with a net lignite thickness of 40 feet. Most lignite beds seem to have fair lateral continuity, and at least some beds are several miles in extent. The thickest known lignite bed was traced for at least 18 miles, from northwest to southeast of Watkins. The lignite is brownish-black to black, weathers, checks, and disintegrates rapidly, and even in drill cores from a few hundred feet in depth the lignite is easily broken by hand pressure. Quality of the lignite is lowered by the non-coal partings and, locally at least, by some small blebs and balls of clay in the lignite itself, especially at the base. Available analyses indicate that the following general figures, on an as-received basis, may be applied to relatively clean lignite from this zone: 6,000-7,000 Btu, 20-35 percent moisture, 8-18 percent ash, and 0.3-0.5 percent sulfur. Rank of the lignite is lignite A as calculated by the formulas of the American Society for Testing and . Materials (ASTM), although some parts, especially of deeper beds, may be as high as subbituminous C coal in rank. Best utilization of the lignite probably would be by gasification, liquefaction, or similar methods, because of the numerous non-coal partings and low quality. The thickest known lignite bed is estimated to contain at least 1.25 billion short tons of lignite. Two methods of roughly estimating the order of magnitude of lignite resources, in beds at least 4 feet thick and within 1,000 feet of the surface in this zone, indicate resources are on the order of 20 billion tons.

Colorado↗
USGS1974

Concentration and mineralogical residence of elements in rich oil shales of the Green River Formation, Piceance Creek Basin, Colorado, and the Uinta Basin, Utah; a preliminary report

Ten core samples of two rich oil-shale beds from the Parachute Creek Member of the Eocene Green River Formation, Piceance Creek basin, Colorado, and Uinta Basin, Utah, were analyzed for 34 major, minor, and trace elements. For 23 of these elements, principal mineralogical residence is established or suggested. Such studies of distribution and mineralogical residence provide important data for predicting the kinds and amounts of elements and compounds--some possibly harmful-that might he released into the environment by oil-shale mining operations. However, because of the many variables involved, no attempt is made to discuss these results in terms of any of the various retorting methods.

Colorado, Utah↗
USGS1975

Preliminary report on the economic potential of the Chattanooga Shale in Tennessee, data as of 1962

The Geological Survey?s investigations of the Chattanooga shale in Tennessee and adjacent states on behalf of the U.S. Atomic Energy Commission consisted mostly of geologic studies and routine analyses of samples for uranium. In the course of the studies, however, other investigations were made, primarily to find answers to specific problems that arose from time to time. The large amount of analytical and related data obtained is here reported, with sufficient explanatory material to bring the data into proper perspective. Although the Survey has not made a comprehensive overall study of the geology, geochemistry, mineralogy, and petrography of the shale, sufficient information has been obtained to provide a sound basis for possible mining and processing of the shale in the future.

Open-File Report↗