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dc.contributor.authorWernicke, Brian
dc.contributor.authorWalker, J. Douglas
dc.contributor.authorBeaufait, Mark S.
dc.date.accessioned2015-03-19T21:39:31Z
dc.date.available2015-03-19T21:39:31Z
dc.date.issued1985-02
dc.identifier.citationWernicke, B., J. D. Walker, and M. S. Beaufait (1985), Structural discordance between neogene detachments and frontal sevier thrusts, central Mormon Mountains, southern Nevada, Tectonics, 4(2), 213–246, http://dx.doi.org/10.1029/TC004i002p00213.en_US
dc.identifier.urihttp://hdl.handle.net/1808/17141
dc.descriptionThis is the published version. Copyright 1985 American Geophysical Union. All Rights Reserved.en_US
dc.description.abstractDetailed geologic mapping in the Mormon Mountains of southern Nevada provides significant insight into processes of extensional tectonics developed within older compressional orogens. A newly discovered, WSW-directed low-angle normal fault, the Mormon Peak detachment, juxtaposes the highest levels of the frontal most part of the east-vergent, Mesozoic Sevier thrust belt with autochthonous crystalline basement. Palinspastic analysis suggests that the detachment initially dipped 20–25° to the west and cut discordantly across thrust faults. Nearly complete lateral removal of the hanging wall from the area has exposed a 5 km thick longitudinal cross-section through the thrust belt in the footwall, while highly attenuated remnants of the hanging wall (nowhere more than a few hundred meters thick) structurally veneer the range. The present arched configuration of the detachment resulted in part from progressive “domino-style” rotation of a few degrees while it was active, but is largely due to rotation on younger, structurally lower, basement-penetrating normal faults that initiated at high-angle.

The geometry and kinematics of normal faulting in the Mormon Mountains suggest that pre-existing thrust planes are not required for the initiation of low-angle normal faults, and even where closely overlapped by extensional tectonism, need not function as a primary control of detachment geometry. Caution must thus be exercised in interpreting low-angle normal faults of uncertain tectonic heritage such as those seen in the COCORP west-central Utah and BIRP's MOIST deep-reflection profiles. Although thrust fault reactivation has reasonably been shown to be the origin of a very few low-angle normal faults, our results indicate that it may not be as fundamental a component of orogenic architecture as it is now widely perceived to be. We conclude that while in many instances thrust fault reactivation may be both a plausible and attractive hypothesis, it may never be assumed.
en_US
dc.publisherAmerican Geophysical Unionen_US
dc.titleStructural discordance between neogene detachments and frontal sevier thrusts, central Mormon Mountains, southern Nevadaen_US
dc.typeArticle
kusw.kuauthorWalker, J. Douglas
kusw.kudepartmentGeologyen_US
kusw.oanotesPer SHERPA/RoMEO, 3/18/15: Author's Pre-print: green tick author can archive pre-print (ie pre-refereeing) Author's Post-print: green tick author can archive post-print (ie final draft post-refereeing) Publisher's Version/PDF: grey tick subject to Restrictions below, author can archive publisher's version/PDF General Conditions:

Authors' Pre-print on authors' personal website or departmental website Authors' Post-print on authors' personal website or departmental website Set statements to accompany submitted, accepted and published articles Publisher copyright and source must be acknowledged with DOI Publisher's version/PDF must be used in Institutional Repository 6 months after publication.
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dc.identifier.doi10.1029/TC004i002p00213
kusw.oaversionScholarly/refereed, publisher version
kusw.oapolicyThis item does not meet KU Open Access policy criteria.
dc.rights.accessrightsopenAccess


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