Refrigeration of the western Cordilleran lithosphere during Laramide shallow-angle subduction

Abstract

Research Article| November 01, 1991 Refrigeration of the western Cordilleran lithosphere during Laramide shallow-angle subduction Trevor A. Dumitru; Trevor A. Dumitru 1Department of Geology, Stanford University, Stanford, California 94305 Search for other works by this author on: GSW Google Scholar Phillip B. Gans; Phillip B. Gans 1Department of Geology, Stanford University, Stanford, California 94305 Search for other works by this author on: GSW Google Scholar David A. Foster; David A. Foster 2Victorian Institute of Earth and Planetary Sciences, Department of Geology, La Trobe University, Bundoora, Victoria 3083, Australia Search for other works by this author on: GSW Google Scholar Elizabeth L. Miller Elizabeth L. Miller 1Department of Geology, Stanford University, Stanford, California 94305 Search for other works by this author on: GSW Google Scholar Author and Article Information Trevor A. Dumitru 1Department of Geology, Stanford University, Stanford, California 94305 Phillip B. Gans 1Department of Geology, Stanford University, Stanford, California 94305 David A. Foster 2Victorian Institute of Earth and Planetary Sciences, Department of Geology, La Trobe University, Bundoora, Victoria 3083, Australia Elizabeth L. Miller 1Department of Geology, Stanford University, Stanford, California 94305 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1991) 19 (11): 1145–1148. https://doi.org/10.1130/0091-7613(1991)019<1145:ROTWCL>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Trevor A. Dumitru, Phillip B. Gans, David A. Foster, Elizabeth L. Miller; Refrigeration of the western Cordilleran lithosphere during Laramide shallow-angle subduction. Geology 1991;; 19 (11): 1145–1148. doi: https://doi.org/10.1130/0091-7613(1991)019<1145:ROTWCL>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The Laramide orogeny has generally been attributed to a shift from normal-angle to shallow-angle subduction beneath the western margin of the North American plate. In addition to important mechanical effects, this shift may have had important thermal effects on the lithosphere in the western Cordillera. Before the Laramide, geothermal gradients in the western Cordillera were probably normal to high because of the presence below of a hot asthenospheric wedge. With the shift to shallow subduction, the wedge was probably expelled and replaced by a cold subducting slab that extended just below the Cordilleran lithosphere. This would shift the western Cordillera into a cold, forearc-like thermal setting dominated by the refrigeration effects of the subducting slab. Thermochronologic data from the Sierra Nevada, Great Basin, Mojave Desert, western Arizona, and perhaps the Colorado Plateau record latest Cretaceous-early Tertiary cooling that may be evidence of such refrigeration. If regional refrigeration occurred, it would have several important implications: (1) metamorphism in the western Cordillera would have waned with the start of the Laramide orogeny; (2) the crust in the western Cordillera would have strengthened and become much more resistant to deformation (e.g., gravitational collapse and extension of thickened crust in the Sevier hinterland would have been impeded); and (3) latest Cretaceous-early Tertiary isotopic cooling ages may not be valid indicators of a period of major regional uplift and unroofng. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.