Reconstructing the kinematic evolution of curved mountain belts: Internal strain patterns in the Wyoming salient, Sevier thrust belt, U.S.A.

Research Article| January 01, 2010 Reconstructing the kinematic evolution of curved mountain belts: Internal strain patterns in the Wyoming salient, Sevier thrust belt, U.S.A. Adolph Yonkee; Adolph Yonkee † 1Department of Geosciences, Weber State University, Ogden, Utah 84408, USA †E-mail: ayonkee@weber.edu. Search for other works by this author on: GSW Google Scholar Arlo Brandon Weil Arlo Brandon Weil 2Department of Geology, Bryn Mawr College, Bryn Mawr, Pennsylvania 19010, USA Search for other works by this author on: GSW Google Scholar GSA Bulletin (2010) 122 (1-2): 24–49. https://doi.org/10.1130/B26484.1 Article history received: 13 Jun 2008 rev-recd: 31 Dec 2008 accepted: 05 Jan 2009 first online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Adolph Yonkee, Arlo Brandon Weil; Reconstructing the kinematic evolution of curved mountain belts: Internal strain patterns in the Wyoming salient, Sevier thrust belt, U.S.A.. GSA Bulletin 2010;; 122 (1-2): 24–49. doi: https://doi.org/10.1130/B26484.1 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 SocietyGSA Bulletin Search Advanced Search Abstract Analyses of mesoscopic structural and strain patterns in red beds of the Triassic Ankareh Formation and limestones of the Jurassic Twin Creek Formation, in concert with complementary paleomagnetic studies, constrain the three-dimensional kinematic evolution of curved fold-and-thrust systems in the Wyoming salient of the Sevier thrust belt. Spaced cleavage, fracture and vein networks, minor folds, and minor faults in limestones and red beds accommodated early layer-parallel shortening (LPS) concentrated in front of the growing thrust wedge, along with minor strike-parallel extension and wrench shear related to the development of orogenic curvature. Strain, estimated using mass balance relations for cleavage seams, crinoid ossicles in bioclastic limestone, and reduction spots in red beds, displays systematic regional patterns. Principal shortening directions are subperpendicular to structural trend around the salient, reflecting a combination of primary curvature and secondary rotation of early LPS fabrics. LPS magnitudes vary from <5% in central parts of the frontal Hogsback thrust system, where cleavage is absent, to 10%–30% in the more interior Crawford thrust system, where cleavage intensity is moderate to strong; strain also increases toward the salient ends. Internal strain is a significant component of total deformation and should be considered when restoring cross sections. Strain patterns are consistent with a kinematic model involving curved fault slip and differential shortening that produced progressive secondary curvature during thrusting. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.