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Crustal structure between Lake Mead, Nevada, and Mono Lake, California

Crustal Studies Technical Letter 22

In cooperation with the Defense Advanced Research Projects Agency
By:

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Abstract

Interpretation of a reversed seismic-refraction profile between Lake Mead, Nevada, and Mono Lake, California, indicates velocities of 6.15 km/sec for the upper layer of the crust, 7.10 km/sec for an intermediate layer, and 7.80 km/sec for the uppermost mantle. Phases interpreted to be reflections from the top of the intermediate layer and the Mohorovicic discontinuity were used with the refraction data to calculate depths. The depth to the Moho increases from about 30 km near Lake Mead to about 40 km near Mono Lake. Variations in arrival times provide evidence for fairly sharp flexures in the Moho. Offsets in the Moho of 4 km at one point and 2 1/2 km at another correspond to large faults at the surface, and it is suggested that fracture zones in the upper crust may displace the Moho and extend into the upper mantle. The phase P appears to be an extension of the reflection from the top of the intermediate layer beyond the critical angle. Bouguer gravity, computed for the seismic model of the crust, is in good agreement with the measured Bouguer gravity. Thus a model of the crustal structure is presented which is consistent with three semi-independent sources of geophysical data: seismic-refraction, seismic-reflection, and gravity.

Geospatial Extents

Additional Publication Details

Publication type:
Report
Publication Subtype:
USGS Unnumbered Series
Title:
Crustal structure between Lake Mead, Nevada, and Mono Lake, California
Series title:
Crustal Studies Technical Letter
Series number:
22
Year Published:
1964
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
Earthquake Science Center, Menlo Park Science Center
Description:
21 p.
Number of Pages:
25
Country:
United States
State:
California;Nevada
Other Geospatial:
Lake Mead;Mono Lake
Online Only (Y/N):
Y