Laboratory Electrical Resistivity Analysis of Geologic Samples from Fort Irwin, California

Open-File Report 2013-1024- E
Prepared in cooperation with the U.S. Army, Fort Irwin National Training Center
By:  and 
Edited by: David C. Buesch

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Abstract

Correlating laboratory resistivity measurements with geophysical resistivity models helps constrain these models to the geology and lithology of an area. Throughout the Fort Irwin National Training Center area, 111 samples from both cored boreholes and surface outcrops were collected and processed for laboratory measurements. These samples represent various lithologic types that include plutonic and metamorphic (basement) rocks, lava flows, consolidated sedimentary rocks, and unconsolidated sedimentary deposits that formed in a series of intermountain basins. Basement rocks, lava flows, and some lithified tuffs are generally resistive (≥100 ohm-meters [Ω·m]) when saturated. Saturated unconsolidated samples are moderately conductive to conductive, with resistivities generally less than 100 Ω·m, and many of these samples are less than 50 Ω·m. The unconsolidated samples can further be separated into two broad groups: (1) younger sediments that are moderately conductive, owing to their limited clay content, and (2) older, more conductive sediments with a higher clay content that reflects substantial amounts of originally glassy volcanic ash subsequently altered to clay. The older sediments are believed to be Tertiary. Time-domain electromagnetic (TEM) data were acquired near most of the boreholes, and, on the whole, close agreements between laboratory measurements and resistivity models were found.

Suggested Citation

Bloss, B.R., and Bedrosian, P.A, 2015, Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California, chap. E of Buesch, D.C., ed., Geology and geophysics applied to groundwater hydrology at Fort Irwin, California: U.S. Geological Survey Open-file Report 2013-1024, 104 p., https://doi.org/10.3133/ofr20131024E.

ISSN: 2331-1258 (online)

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Additional publication details

Publication type Report
Publication Subtype USGS Numbered Series
Title Laboratory electrical resistivity analysis of geologic samples from Fort Irwin, California
Series title Open-File Report
Series number 2013-1024
Chapter E
DOI 10.3133/ofr20131024E
Year Published 2015
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description Report: vii, 104 p.; Supplemental Data ReadMe; Supplemental Data ZIP
Larger Work Type Report
Larger Work Subtype USGS Numbered Series
Larger Work Title Geology and geophysics applied to groundwater hydrology at Fort Irwin, California
Country United States
State California
County San Bernardino County
City Fort Irwin
Online Only (Y/N) Y
Additional Online Files (Y/N) Y