Geophysical framework of the Peninsular Ranges batholith—Implications for tectonic evolution and neotectonics

GSA Memoirs
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Abstract

The crustal structure of the Peninsular Ranges batholith can be divided geophysically into two parts: (1) a western mafic part that is dense, magnetic, and characterized by relatively high seismic velocities (>6.25 km/s), low heat flow (<60 mW/m2), and relatively sparse seismicity, and (2) an eastern, more felsic part that is less dense, weakly magnetic, and characterized by lower seismic velocities (<6.25 km/s), high heat flow (>60 mW/m2), and abundant microseismicity. Potential-field modeling indicates that the dense, mafic part of the batholith extends to depths of at least 20 km and likely to the Moho. The magnetic anomalies of the western part of the batholith extend south beyond the spatially extensive exposures of the batholith to the tip of the Baja California peninsula, which suggests that the mafic part of the batholith projects beneath Cenozoic volcanic cover another 400 km. The linearity and undisrupted nature of the magnetic belt of anomalies suggest that the western part of the batholith has behaved as a rigid block since emplacement of the batholith. The batholith may have influenced not only the development of the Gulf of California oblique rift, but also strike-slip faulting along its northern margin, and transtensional faulting along its western margin, likely because it is thermally and mechanically more resistant to deformation than the surrounding crust.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Geophysical framework of the Peninsular Ranges batholith—Implications for tectonic evolution and neotectonics
Series title GSA Memoirs
DOI 10.1130/2014.1211(01)
Volume 211
Year Published 2014
Language English
Publisher Geological Society of America
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description 20 p.
First page 1
Last page 20
Country Mexico, United States
State California
Online Only (Y/N) N
Additional Online Files (Y/N) N