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dc.contributor.authorCarrapa, B.
dc.contributor.authorDeCelles, P. G.
dc.contributor.authorRomero, M.
dc.date.accessioned2019-07-30T23:14:16Z
dc.date.available2019-07-30T23:14:16Z
dc.date.issued2019-02-16
dc.identifier.citationCarrapa, B., DeCelles, P. G., & Romero, M. ( 2019). Early inception of the Laramide orogeny in southwestern Montana and northern Wyoming: Implications for models of flat‐slab subduction. Journal of Geophysical Research: Solid Earth, 124, 2102– 2123. https://doi.org/10.1029/2018JB016888en_US
dc.identifier.issn2169-9313
dc.identifier.issn2169-9356
dc.identifier.doi10.1029/2018jb016888
dc.identifier.urihttp://hdl.handle.net/10150/633590
dc.description.abstractTiming and distribution of magmatism, deformation, exhumation, and basin development have been used to reconstruct the history of Laramide flat-slab subduction under North America during Late Cretaceous-early Cenozoic time. Existing geodynamic models, however, ignore a large (40,000-km(2)) sector of the Laramide foreland in southwestern Montana. The Montana Laramide ranges consist of Archean basement arches (fault-propagation folds) that were elevated by thrust and reverse faults. We present new thermochronological and geochronological data from six Laramide ranges in southwestern Montana (the Beartooth, Gravelly, Ruby and Madison Ranges, and the Tobacco Root and Highland Mountains) that show significant cooling and exhumation during the Early to mid-Cretaceous, much earlier than the record of Laramide exhumation in Wyoming. These data suggest that Laramide-style deformation-driven exhumation slightly predates the eastward sweep of magmatism in western Montana, consistent with geodynamic models involving initial strain propagation into North American cratonic rocks due to stresses associated with a northeastward expanding region of flat-slab subduction. Our results also indicate various degrees of Cenozoic heating and cooling possibly associated with westward rollback of the subducting Farallon slab, followed by Basin-and-Range extension. Plain Language Summary The Laramide region in the western U.S. is characterized by some of the highest topography in North America including the Wind River Range in WY and the Beartooth Range of WY and Montana. These ranges have fed detritus to surrounding basins for millions of years and contributed to modern ecosystems. These high topographic features and basins have significantly impacted paleoenvironmental conditions over geological time. The formation of these high-relief ranges has been linked to deep Earth, geodynamic, processes involving subduction of a flat slab under the North American Plate. Models of flat-slab subduction rely on the timing and pattern of deformation and exhumation of Laramide ranges, which remains poorly understood. Our study provides new data on the timing of deformation and exhumation of Laramide ranges in SW Montana and northern WY capable of testing current models of flat-slab subduction.en_US
dc.description.sponsorshipNSF-Tectonics [EAR-1524151]en_US
dc.language.isoenen_US
dc.publisherAMER GEOPHYSICAL UNIONen_US
dc.relation.urlhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JB016888en_US
dc.rights©2019. American Geophysical Union. All Rights Reserved.en_US
dc.subjectLaramideen_US
dc.subjectflat-slab subductionen_US
dc.subjectMontanaen_US
dc.subjectWyomingen_US
dc.titleEarly Inception of the Laramide Orogeny in Southwestern Montana and Northern Wyoming: Implications for Models of Flat‐Slab Subductionen_US
dc.typeArticleen_US
dc.contributor.departmentUniv Arizona, Dept Geoscien_US
dc.identifier.journalJOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTHen_US
dc.description.note6 month embargo; published online: 9 January 2019en_US
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en_US
dc.eprint.versionFinal published versionen_US
dc.source.volume124
dc.source.issue2
dc.source.beginpage2102-2123
refterms.dateFOA2019-07-09T00:00:00Z


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