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Stephen L. Robbins

Publications and source records attributed to Stephen L. Robbins.

12 recordsLinked to original sources
USGS2011

Standardization of gravimeter calibrations in the geological survey

The calibration of gravimeters has long been primarily the concern of geodesists involved in measuring large gravity differences, but recent developments suggest that the precision and stability of gravimeter calibrations may have greater geologic importance in the future. First, the use of high-speed computers and an increasing variety of supplemental data now make possible the geologic interpretation of gravity anomalies so small that they would not have been noticed in surveys made ten years ago. The kind of gravity interpretation that identifies small reefs and local accumulations of petroleum [ McCulloh , 1967] often requires local increases in station density and the assurance that the calibration of meters used in all parts of a survey are compatible. Second, temporal changes of gravity have already been measured in connection with earthquakes [ Barnes , 1966], volcanic eruptions [ Iida et al , 1952], and the movement of ice caps [ Behrendt , 1967]; they are now being considered for several other types of geologic processes.

Alaska, Arizona, California, Colorado, Oregon, Was↗
USGS1979

In situ bulk density and porosity estimates from borehole gravity data in limestones of the Madison Group; test well No. 1, Crook County, Wyoming

In 1975 the U.S. Geological Survey, in cooperation with the Old West Regional Commission, prepared a plan of study (U.S. Geological Survey, 1975) for evaluating the water-supply potential of limestone of the Madison Group and associated rocks. To obtain better subsurface hydrologic and geologic information it was recognized that Madison Group test wells would have to be drilled. This report tabulates the results of in situ bulk density and porosity determinations from borehole gravity data obtained in the first of these wells, test well no. 1.

Wyoming↗
USGS1979

Borehole gravity surveys in native-sulfur deposits, Culberson and Pecos counties, Texas

Native-sulfur deposits in west Texas are heterogeneous, with sulfur content and formation properties varying significantly over small vertical and horizontal distances. The zone of recovery of the Frasch process extends tens or even hundreds of feet around each recovery well, but the investigation depth of most wire-line logs is measured in inches. Consequently, the analysis of drill cores is still the primary method for the evaluation of sulfur deposits.

Texas↗
USGS1978

Principal facts for borehole gravity stations in stratigraphic test well ERDA No. 9, Eddy County, New Mexico

Since 1972 the U.S. Geological Survey has been conducting a series of field evaluation studies in southeastern New Mexico for the Waste Management Division of the Department of Energy (formerly U.S. Energy Research and Development Administration). On the basis of these studies, a tentative site for a nuclear waste repository/disposal facility has been selected near the center of the Los Medafios area in Eddy and Lea Counties, New Mexico (Fig. 1). The proposed host rock for the emplacement of nuclear waste at the potential repository site consists of the bedded evaporite deposits of the Salado Formation. Numerous test holes have been drilled in the Los Medafios area to determine geologic conditions and to obtain geophysical data and rock samples for additional site-evaluation studies. This report tabulates borehole gravity data acquired in one of these test holes, ERDA No. 9, and summarizes the geology of the consolidated rock formations in which gravity observations were made.

New Mexico↗
USGS1978

Principal facts for borehole gravity stations in test well Ue 19z, exploratory drill hole PM-1, and water well 5a, Nevada Test Site, Nye County, Nevada

During field studies conducted in October 1977 and March 1978, borehole gravity surveys were completed by the U.S. Geological Survey at the Nevada Test Site in test well Ue19z, exploratory drill hole PH-1, and water well 5a. The U.S. Geological Survey-LaCoste and Romberg-1/ borehole gravity meter (McCulloh and others, 1967a; McCulloh and others, 1967b) was used in the logging program. The primary objective of this work was to obtain data for the determination of accurate in situ formation densities utilizing an instrument not significantly affected by casing, borehole rugosity, or other near-borehole conditions. This report provides a brief summary of the geology of the rock formations penetrated by drill holes Ue 19z, PH-1, and water well 5a, and tabulates the subsurface gravity data obtained in these, wells. Reduced sections of the gamma-ray logs run in PM-1 and 5a are also included.

Nevada↗