Journal article

Thermal evolution of a sheared continental margin: Insights from the Ballenas transform in Baja California, Mexico

Christian Seiler, Andrew JW Gleadow, John M Fletcher, Barry P Kohn



The Ballenas transform margin in central Baja California offers an unparalleled opportunity to study the thermal behaviour of a sheared continental margin during various stages of its evolution. Apatite fission track and (U-Th)/He results from two transects perpendicular to the coast reveal a pronounced latest Pliocene to Pleistocene (~ 1.8 Ma) heating event related to the Neogene opening of the Gulf of California. Proximity to a regional pre-rift unconformity indicates that samples remained at near-surface levels since Paleogene unroofing, despite having experienced reheating to maximum paleotemperatures within or above the fission track partial annealing zone. In general, maximum paleotemp..

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Awarded by ARC

Awarded by CONACYT

Funding Acknowledgements

Funding for this research was provided by ARC grant DP0665127 to AJWG and BPK and by CONACYT grant # 81463 to JMF. CS received additional support by MIFRS and MIRS scholarships and the David Hay Memorial Fund. The Melbourne Thermochronology Lab receives infrastructure support under the AuScope Program of NCRIS and irradiation costs were covered by an AINSE grant. The authors are grateful to Ramon Mendoza-Borunda for his assistance in the field. Arturo Martin-Barajas and Antonio Resendiz are thanked for their help and logistical support during field work. Technical assistance by Abaz Alimanovic for (U-Th)/He and Graham Hutchinson for electron microprobe analyses is greatly appreciated. We thank two anonymous reviewers for their valuable comments.