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Pacific-North America plate motion and opening of the Upper Delfín basin, northern Gulf of California, Mexico

Oskin, Michael and Stock, Joann (2003) Pacific-North America plate motion and opening of the Upper Delfín basin, northern Gulf of California, Mexico. Geological Society of America Bulletin, 115 (10). pp. 1173-1190. ISSN 0016-7606. http://resolver.caltech.edu/CaltechAUTHORS:20140423-095857093

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Abstract

Correlation of conjugate rifted margins of the Upper Delfín basin constrains the timing and amount of transtensional opening along the Pacific–North America plate boundary in the northern Gulf of California. Lithologic, geochemical, paleomagnetic, and geochronologic data from a set of four ignimbrites, consisting of eight distinctive cooling units, are shown to correlate from northeastern Baja California to Isla Tiburón and adjacent areas of western Sonora. These matching ignimbrites are the ca. 12.6 Ma tuff of San Felipe, the 6.3 ± 0.2 Ma tuffs of Mesa Cuadrada (Tmr3 and Tmr4), the tuffs of Dead Battery Canyon (Tmr5), and the 6.1 ± 0.5 Ma tuffs of Arroyo El Canelo. Offset distributions and facies patterns of these ignimbrites support 255 ± 10 km of opening between conjugate rifted margins of the Upper Delfín basin. Addition of deformation from the continental margins of this basin indicates at least 276 ± 13 km of Pacific–North America plate motion between coastal Sonora and the main gulf escarpment in Baja California since ca. 6 Ma; a further 20 ± 10 km of northwestward displacement of Isla Tiburón relative to coastal Sonora occurred sometime after 12.6 Ma. These reconstructions agree with earlier estimates of slip across the Gulf of California and on the San Andreas fault system of southern California, but require that the Pacific–North America plate boundary became localized in the gulf at ca. 6 Ma. The restored continental margins of the Upper Delfín basin show that only a 20–25 km width of upper continental crust has foundered beneath this part of the northern Gulf of California. This result suggests that most of the crustal area formed by opening of the Upper Delfín basin was either exhumed from lower-crustal levels or is new transitional oceanic crust.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1130/B25154.1DOIArticle
http://bulletin.geoscienceworld.org/content/115/10/1173PublisherArticle
http://gsabulletin.gsapubs.org/content/115/10/1173PublisherArticle
ORCID:
AuthorORCID
Stock, Joann0000-0003-4816-7865
Additional Information:© 2003 Geological Society of America. Data Repository item 2003134. Manuscript received by the Society 18 March 2002. Revised manuscript received 26 December 2002. Manuscript accepted 17 February 2003. Support was provided by National Science Foundation grants EAR-9614674 and EAR-0001248 and a grant from the University of California MEXUS program. We appreciate the support of Jaime Roldán-Quintana and Carlos González-Leόn, of the Universidad Nacional Autόnoma de México. Permission to enter Isla Tiburόn was granted by the Secretaria de Medio Ambiente y Recursos Naturales and the Cumcaác (Seri) Indian Tribe. Prescott College Research Station. Bahía Kino, generously provided logistical support during field studies. We are especially grateful to our Cumcaác guide. Ernesto Molina, Scott Dobner, Ivlatt Bachman, Robert Houston, Jason Wise, Naomi Marks, and Lesley Perg assisted with field studies. Discussions with Gary Axen, Arturo Martín-Barajas. Elizabeth Nagy, and Claudia Lewis, and reviews by Paul Umhoefer and John Fletcher contributed to the development of this paper. California Institute of Technology Publication #8869.
Group:Seismological Laboratory
Funders:
Funding AgencyGrant Number
NSFEAR-9614674
NSFEAR-0001248
University of California MEXUS programUNSPECIFIED
Universidad Nacional Autόnoma de MéxicoUNSPECIFIED
Subject Keywords:Gulf of California, Mexico, rifting, ignimbrite, plate motion, palinspastic restoration.
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences8869
Record Number:CaltechAUTHORS:20140423-095857093
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20140423-095857093
Official Citation: Michael Oskin and Joann Stock Pacific–North America plate motion and opening of the Upper Delfín basin, northern Gulf of California, Mexico Geological Society of America Bulletin, , v. 115, p. 1173-1190, doi:10.1130/B25154.1
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:45140
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:23 Apr 2014 17:49
Last Modified:04 Dec 2015 18:52

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