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Gravity and Magnetic Investigations of the Mojave National Preserve and Adjacent Areas, California and Nevada

Open-File Report 2009-1117

Prepared in cooperation with National Park Service
By:
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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.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Gravity and Magnetic Investigations of the Mojave National Preserve and Adjacent Areas, California and Nevada
Series title:
Open-File Report
Series number:
2009-1117
Edition:
Version 1.0
Year Published:
2009
Language:
ENGLISH
Publisher:
U.S. Geological Survey
Contributing office(s):
Geophysics Unit of Menlo Park, CA (GUMP)
Description:
Report: iii, 25 p.; ReadMe; Metadata; Data; Rock Properties
Online Only (Y/N):
Y
Additional Online Files(Y/N):
Y