Journal article
Low-temperature thermochronology of northern Baja California, Mexico: Decoupled slip-exhumation gradients and delayed onset of oblique rifting across the Gulf of California
C Seiler, JM Fletcher, BP Kohn, AJW Gleadow, A Raza
Tectonics | AMER GEOPHYSICAL UNION | Published : 2011
DOI: 10.1029/2009TC002649
Abstract
The northern Gulf Extensional Province displays key structural relationships that characterize the magnitude, direction, and timing of Neogene rift-related transtension during the opening of the Gulf of California. Apatite fission track and (U-Th)/He thermochronology from the Sierra San Felipe document moderate cooling (4°C/Myr-7°C/Myr) during the early Paleogene associated with progressive unroofing caused by erosional downwearing of the ancestral Peninsular Ranges. Beginning at ∼45-35 Ma, a period of tectonic quiescence with low cooling rates (≤1°C/Myr) marks the development of a regional Oligocene-Miocene peneplain. Rift-related exhumation began at ∼9-7 Ma and attains ∼2.5 km in the hinge..
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Awarded by CONACYT
Awarded by NSF
Funding Acknowledgements
Funding for this research was provided by grants from the Australian Research Council to A.J.W.G. and B.P.K., and by grants CONACYT 81463 and NSF EAR-0739017 Sub-Award 08-004375-01 to J.M.F. C.S. received additional support from MIFRS and MIRS scholarships and the David Hay Memorial Fund awarded by the University of Melbourne. The Melbourne Thermochronology Lab receives infrastructure support under the AuScope Program of NCRIS, and neutron irradiation costs were partially covered by AINSE. Technical assistance by Abaz Alimanovic for (U-Th)/He and Graham Hutchinson for electron microprobe analyses is greatly appreciated. This paper benefited greatly from the thoughtful and constructive comments by Associate Editor Bob Miller, Mike Oskin, and an anonymous reviewer.