Peninsular Ranges Batholith, Baja California and Southern California

Geophysical framework of the Peninsular Ranges batholith—Implications for tectonic evolution and neotectonics
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Published:January 01, 2014
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CiteCitation
V.E. Langenheim, R.C. Jachens, C. Aiken, 2014. "Geophysical framework of the Peninsular Ranges batholith—Implications for tectonic evolution and neotectonics", Peninsular Ranges Batholith, Baja California and Southern California, Douglas M. Morton, Fred K. Miller
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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.
- Baja California
- batholiths
- block structures
- Cretaceous
- crust
- deformation
- East Pacific
- faults
- geophysical methods
- gravity anomalies
- Gulf of California
- heat flow
- intrusions
- mafic composition
- magnetic anomalies
- magnetic methods
- magnetic properties
- Mesozoic
- Mexico
- Mohorovicic discontinuity
- neotectonics
- North America
- North Pacific
- Northeast Pacific
- Pacific Ocean
- Peninsular Ranges Batholith
- plate tectonics
- potential field
- rifting
- San Andreas Fault
- seismic methods
- seismicity
- systems
- tectonics