Fault zone characteristics and basin complexity in the southern Salton Trough, California

Geology
By: , and 

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Abstract

Ongoing oblique slip at the Pacific–North America plate boundary in the Salton Trough produced the Imperial Valley (California, USA), a seismically active area with deformation distributed across a complex network of exposed and buried faults. To better understand the shallow crustal structure in this region and the connectivity of faults and seismicity lineaments, we used data primarily from the Salton Seismic Imaging Project to construct a three-dimensional P-wave velocity model down to 8 km depth and a velocity profile to 15 km depth, both at 1 km grid spacing. A VP = 5.65–5.85 km/s layer of possibly metamorphosed sediments within, and crystalline basement outside, the valley is locally as thick as 5 km, but is thickest and deepest in fault zones and near seismicity lineaments, suggesting a causative relationship between the low velocities and faulting. Both seismicity lineaments and surface faults control the structural architecture of the western part of the larger wedge-shaped basin, where two deep subbasins are located. We estimate basement depths, and show that high velocities at shallow depths and possible basement highs characterize the geothermal areas.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Fault zone characteristics and basin complexity in the southern Salton Trough, California
Series title Geology
DOI 10.1130/G38033.1
Volume 44
Issue 9
Year Published 2016
Language English
Publisher Geological Society of America
Contributing office(s) Earthquake Science Center
Description 4 p.
First page 747
Last page 750
Country United States
State California
Other Geospatial Salton Trough