Langenheim, Victoria E. Morita, Andrew Christensen, Allen H. 20191210 tabular digital data https://doi.org/10.3133/ofr20191128> Depth to bedrock in the eastern part of Edwards Air Force Base, southern California, was modeled by inversion of gravity data and wells that intercepted bedrock. Depth to bedrock, well data, and gravity data provide information on the geohydrologic framework of eastern Edwards Air Force Base, California. 19600101 20190603 ground condition Complete None planned eastern Edwards Air Force Base, southern California -118.0 -117.5 35.17 34.75 ISO 19115 Topic Category biota USGS Thesaurus bedrock geologic units None Edwards Air Force Base, southern California None. Please see 'Distribution Info' for details. None. Users are advised to read the data set's metadata thoroughly to understand appropriate use and data limitations. Victoria E Langenheim U.S. Geological Survey, SOUTHWEST REGION Research Geophysicist mailing address

Mail Stop 989, 345 Middlefield Road

Menlo Park CA 94025 United States 650-329-5313 650-329-5133 zulanger@usgs.gov Funding was provided by Edwards Air Force Base Modeled depth to bedrock was compared to total depths of wells interpreted to have bottomed in basin-fill deposits. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. Elevations of new gravity data are accurate to 1 foot or better. Depth to bedrock interpreted from wells may be off by as much as 50 feet. The modeled depth to bedrock is accurate to about 50 feet where constrained by nearby well information and gravity data. Pan-American Center for Earth and Environmental Studies 20100108 tabular digital data http://irpsvgis00.utep/repositorywebsite Digital and/or Hardcopy 19600101 20100108 ground condition Gravity data of eastern Edwards Air Force base and vicinity, California gravity data Observed gravity values were corrected for tidal variations and instrument drift. All the gravity measurements were reduced to free-air anomalies using standard formulas (see Telford and others, 1990). Bouguer, curvature, and terrain adjustments to a radial distance of 166.7 km were applied to the free-air anomaly at each station to determine the complete Bouguer anomalies at a standard crustal reduction density of 2,670 kg/m3 (Plouff, 1977). An isostatic adjustment was then applied to remove the long-wavelength effect of deep crustal and/or upper mantle masses that isostatically support regional topography. The isostatic adjustment assumes an Airy-Heiskanen model (Heiskanen and Vening-Meinesz, 1958) of isostatic compensation. Compensation is achieved by varying the depth of the model crust-mantle interface, using the following parameters: a sea-level crustal thickness of 25 km, a crust-mantle density contrast of 400 kg/m3, and a crustal density of 2,670 kg/m3 for the topographic load. These data, along with the wells interpreted to have intercepted bedrock, were then modeled using the inversion method of Jachens and Moring (1990). These results were then compared with the wells interpreted to have bottomed in basin-fill deposits. Please see report for additional details. Jachens, R.C., and Moring, B.C., 1990, Maps of the thickness of Cenozoic deposits and the isostatic residual gravity over basement for Nevada: U.S. Geological Survey Open-File Report 90–404, 15 p., 2 plates. Heiskanen, W.A., and Vening-Meinesz, F.A., 1958, The Earth and its gravity field: New York, McGraw-Hill Book Company, Inc., 470 p. Morelli, Carlo, ed., 1974, The International Gravity Standardization Net 1971: International Association of Geodesy Special Publication no. 4, 194 p. Plouff, Donald, 1977, Preliminary documentation for a FORTRAN program to compute gravity terrain corrections based on topography digitized on a geographic grid: U.S. Geological Survey Open-File Report 77-535, 45 p. Telford, W.M., Geldart, L.O., Sheriff, R.E., and Keyes, D.A., 1990, Applied Geophysics (Second Edition): New York, Cambridge University Press, 770 p. 20190601 Victoria E Langenheim U.S. Geological Survey, SOUTHWEST REGION Research Geophysicist mailing address

Mail Stop 989, 345 Middlefield Road

Menlo Park CA 94025 United States 650-329-5313 650-329-5133 zulanger@usgs.gov gravity_data.csv Comma Separated Value (CSV) file containing data. Producer defined PB1104 name Producer defined name assigned to gravity measurement; new data have suffixes of 16EDW and 17EDW. 34 latitude degree (NAD27 datum) Producer defined 34 35 degree 54.75 latitude minute (NAD27 datum) Producer defined 0.0 59.99 minute -117 longitude degree (NAD27) Producer defined -117 117 degree 42.71 longitude minute (NAD27 datum) Producer defined 0.0 59.96 minute 2738.4 elevation (NGVD29 datum) Producer defined 2262.1 3371.0 feet 979462.12 observed gravity Producer defined 979403.12 979505.18 mGal -5.79 free-air gravity anomaly Producer defined -43.15 12.73 mGal -99.19 simple Bouguer gravity anomaly Producer defined -128.96 -86.47 mGal 0.12 inner zone terrain correction (extent defined by code column) Producer defined 0.0 4.08 mGal 0.39 total terrain correction Producer defined 0.01 6.38 mGal Mcode that gives extent of inner zone terrain correctionProducer defined D correction out to 590 m from measurement Producer defined O correction out to X m from measurement Producer defined << empty cell >> unknown Producer defined M correction out of 2000 m from measurement Producer defined -99.77 complete Bouguer gravity anomaly Producer defined -129.0 -87.25 mGal -16.54 isostatic gravity anomaly Producer defined -45.48 -3.99 mGal depth_to_bedrock.csv Comma Separated Value (CSV) file containing data. Producer defined -118 longitude (NAD27 datum) Producer defined -118.005 -117.421 degree 34.7489 latitude (NAD27 datum) Producer defined 34.7489 35.167 degree -5919.8701 depth to bedrock measured from ground surface Producer defined -13853.6279 0.0 feet basin_wells.csv wells that bottomed in basin-fill deposits Producer defined 009N006W well_id Producer defined identification of well -117.5529 longitude (NAD27 datum) Producer defined -117.9174 -117.5196 degree 34.8736 latitude (NAD27 datum) Producer defined 34.8225 35.0739 46 total depth of well that bottomed in basin-fill deposits (measured from ground surface) Producer defined 8.0 3500.0 feet 102.6723 depth to bedrock from model at well location Producer defined 0.0 3396.6672 feet basement_wells.csv Comma Separated Value (CSV) file containing data. Producer defined 009N008W well_id Producer defined well identification 34.90529282 latitude (NAD27 datum) Producer defined 34.84896218 35.0425 feet -117.756414 longitude (NAD27 datum) Producer defined -117.88333329999999 -117.536627 degree 459 depth to bedrock in well interpreted to have intercepted bedrock (measured from ground surface) Producer defined 0.0 2115.0 feet 453.332 depth to bedrock at well location from model Producer defined 0.0 2117.9 feet Gravity and well data were used to model depth to bedrock in the eastern Edwards Air Force Base and vicinity, southern California. Bedrock is defined as pre-Cenozoic in age. Langenheim, V.E., Morita, Andrew, and Christensen, Allen, H., 2019, Depth to bedrock based on modeling of gravity data in the eastern part of Edwards Air Force base, California Victoria E Langenheim U.S. Geological Survey, SOUTHWEST REGION Research Geophysicist mailing address

Mail Stop 989, 345 Middlefield Road

Menlo Park CA 94025 United States 650-329-5313 650-329-5133 zulanger@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.3133/ofr20191128> None 20190605 Victoria E Langenheim U.S. Geological Survey, SOUTHWEST REGION Research Geophysicist mailing address

Mail Stop 989, 345 Middlefield Road

Menlo Park CA 94025 United States 650-329-5313 650-329-5133 zulanger@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999