Geophysical Unit of Menlo Park, Calif.
Isostatic gravity field. Anomalies reflect local density variations in the middle and upper crust (from figure 3).
Cenozoic basins in eastern Nevada and western Utah constitute major ground-water recharge areas in the eastern part of the Great Basin and these were investigated to characterize the geologic framework of the region. Prior to these investigations, regional gravity coverage was variable over the region, adequate in some areas and very sparse in others. Cooperative studies described herein have established 1,447 new gravity stations in the region, providing a detailed description of density variations in the middle to upper crust. All previously available gravity data for the study area were evaluated to determine their reliability, prior to combining with our recent results and calculating an up-to-date isostatic residual gravity map of the area. A gravity inversion method was used to calculate depths to pre-Cenozoic basement rock and estimates of maximum alluvial/volcanic fill in the major valleys of the study area. The enhanced gravity coverage and the incorporation of lithologic information from several deep oil and gas wells yields a much improved view of subsurface shapes of these basins and provides insights useful for the development of hydrogeologic models for the region.
Download this report as a nine-page PDF file (of2007-1190.pdf; 3.4 MB).
Download Table 1 as a .xls spreadsheet. This table contains data collected at the 434 stations from the current study; you can work with the data in this file format (of2007-1190_table1.xls; 70 kB).
For questions about the content of this report, contact Ed Mankinen
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| Western Open-File Reports for 2007 |
| Geologic Division | Geophysical Unit of Menlo Park, Calif. (GUMP) |