CaltechAUTHORS
  A Caltech Library Service

Uniform-sense normal simple shear of the continental lithosphere

Wernicke, Brian (1985) Uniform-sense normal simple shear of the continental lithosphere. Canadian Journal of Earth Sciences, 22 (1). pp. 108-125. ISSN 1480-3313. https://resolver.caltech.edu/CaltechAUTHORS:20190924-075440069

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20190924-075440069

Abstract

Geophysical studies suggest that the thin crust characteristic of the Basin and Range Province extends eastward beneath the west margin of the Colorado Plateau and Rocky Mountain regions. In Arizona and Utah, zones perhaps over 100 km wide may be defined, bounded on the west by the east limit of upper crustal normal faults that account for more that 10% extension and on the east by the east limit of thinning beneath the Colorado Plateau. A discrepancy exists within these zones between the negligible extension measurable in the upper crust and the substantial extension apparent from crustal thinning, assuming the "discrepant zone" crust was as thick as or thicker than the Colorado Plateau – Rocky Mountain crust prior to extensional tectonism.If various theories appealing to crustal erosion are dismissed, mass balance problems evident in the discrepant zones are most easily resolved by down-to-the-east normal simple shear of the crust, moving lower and middle crustal rocks that initially were within the zones up-and-to-the-west to where they now are locally exposed in the Basin and Range Province. West of the discrepant zones in both Arizona and Utah, east-directed extensional allochthons with large displacement are exposed. These geophysical and geological observations complement one another if it is accepted that the entire crust in both Arizona and Utah failed during extension on gently east-dipping, east-directed, low-angle normal faults and shear zones over a region several hundred kilometres wide.Large-scale, uniform-sense normal simple shear of the crust suggests the entire lithosphere may do the same. Such a hypothesis predicts major lithospheric thinning without crustal thinning will occur in plateau areas in the direction of crustal shear. In the case of the Arizona, Utah, and Red Sea extensional systems, and possibly the Death Valley extensional terrain, a broad topographic arch, typically 1500–2000 m higher than the extended terrain, is present, suggesting lithospheric thinning in areas predicted by the hypothesis.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.1139/e85-009DOIArticle
https://pubs.geoscienceworld.org/cjes/article/22/1/108/106070PublisherArticle
ORCID:
AuthorORCID
Wernicke, Brian0000-0002-7659-8358
Additional Information:© 1985 NRC Research Press. Received February 7, 1984; Revision accepted July 12, 1984. Research leading to this report has been funded by National Science Foundation grants EAR 7713637 to B. C. Burchfiel. EAR 7926346 to B. C. Burchfiel and P. Molnar, and EAR 8219034 to B. P. Wernicke. Discussions with J. M. Bartley and R. J. O'Connell have greatly clarified for me some of the concepts upon which this paper is based. I thank P. C. England and J. M. Bartley for reviewing an early draft of this manuscript and R. A. Price and K. R. McClay for helpful, critical reviews of the penultimate draft.
Funders:
Funding AgencyGrant Number
NSFEAR-7713637
NSFEAR-7926346
NSFEAR-8219034
Issue or Number:1
Record Number:CaltechAUTHORS:20190924-075440069
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20190924-075440069
Official Citation:Uniform-sense normal simple shear of the continental lithosphere. Brian Wernicke. Canadian Journal of Earth Sciences, 1985, 22:108-125, https://doi.org/10.1139/e85-009
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:98818
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:24 Sep 2019 16:14
Last Modified:03 Oct 2019 21:44

Repository Staff Only: item control page