dc.contributor.author | Wernicke, Brian | |
dc.contributor.author | Walker, J. Douglas | |
dc.contributor.author | Beaufait, Mark S. | |
dc.date.accessioned | 2015-03-19T21:39:31Z | |
dc.date.available | 2015-03-19T21:39:31Z | |
dc.date.issued | 1985-02 | |
dc.identifier.citation | Wernicke, 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.uri | http://hdl.handle.net/1808/17141 | |
dc.description | This is the published version. Copyright 1985 American Geophysical Union. All Rights Reserved. | en_US |
dc.description.abstract | Detailed 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.publisher | American Geophysical Union | en_US |
dc.title | Structural discordance between neogene detachments and frontal sevier thrusts, central Mormon Mountains, southern Nevada | en_US |
dc.type | Article | |
kusw.kuauthor | Walker, J. Douglas | |
kusw.kudepartment | Geology | en_US |
dc.identifier.doi | 10.1029/TC004i002p00213 | |
kusw.oaversion | Scholarly/refereed, publisher version | |
kusw.oapolicy | This item does not meet KU Open Access policy criteria. | |
dc.rights.accessrights | openAccess | |