Publication Citation

USGS Series Open-File Report
Report Number 2009-1117
Title Gravity and Magnetic Investigations of the Mojave National Preserve and Adjacent Areas, California and Nevada
Edition Version 1.0 Online Only
Language ENGLISH
Author(s) Langenheim, V. E.; Biehler, S.; Negrini, R.; Mickus, K.; Miller, D. M.; Miller, R. J.
Year 2009
Originating office Geophysics Unit of Menlo Park, Calif.
USGS Library Call Number
Physical description Report: iii, 25 p.; ReadMe; Metadata; Data; Rock Properties
ISBN
Northernmost latitude 0354500
Southernmost latitude 0343000
Easternmost longitude -1144500
Westernmost longitude -1163000

Online Document Versions

Copies of the original may be available.

For more information or ordering assistance, call 1-888-ASK-USGS (1-888-275-8747), visit http://ask.usgs.gov, contact any USGS Earth Science Information Center (ESIC), or write:

USGS Information Services
Box 25286
Denver, CO 80225
Abstract

Gravity and aeromagnetic data provide the underpinnings of a hydrogeologic framework for the Mojave National Preserve by estimating the thickness of Cenozoic deposits and locating inferred structural features that influence groundwater flow. An inversion of gravity data indicates that thin (<1 km) basin deposits cover much of the Preserve, except for Ivanpah Valley and the Woods Mountains volcanic center. Localized areas of Cenozoic deposits thicker than 500 m are predicted beneath parts of Lanfair Valley, Fenner Valley, near Kelso, Soda Lake, and southeast of Baker. Along the southern margin of the Mojave National Preserve, basins greater than 1 km deep are located between the Clipper and Marble Mountains, between the Marble and Bristol Mountains, and south of the Bristol Mountains near Amboy. Both density and magnetization boundaries defined by horizontal-gradient analyses coincide locally with Cenozoic faults and can be used to extend these faults beneath cover. Magnetization boundaries also highlight the structural grain within the crystalline rocks and may serve as a proxy for fracturing, an important source of permeability within the generally impermeable basement rocks, thus mapping potential groundwater pathways through and along the mountain ranges in the study area.