Belt of Sigmoidal Bending and Right-Lateral Faulting in the Western Great Basin

Abstract

Research Article| February 01, 1967 Belt of Sigmoidal Bending and Right-Lateral Faulting in the Western Great Basin JOHN P ALBERS JOHN P ALBERS U. S. Geological Survey, Menlo Park, California Search for other works by this author on: GSW Google Scholar Author and Article Information JOHN P ALBERS U. S. Geological Survey, Menlo Park, California Publisher: Geological Society of America Received: 15 Nov 1965 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Copyright © 1967, The Geological Society of America, Inc. Copyright is not claimed on any material prepared by U.S. government employees within the scope of their employment. GSA Bulletin (1967) 78 (2): 143–156. https://doi.org/10.1130/0016-7606(1967)78[143:BOSBAR]2.0.CO;2 Article history Received: 15 Nov 1965 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation JOHN P ALBERS; Belt of Sigmoidal Bending and Right-Lateral Faulting in the Western Great Basin. GSA Bulletin 1967;; 78 (2): 143–156. doi: https://doi.org/10.1130/0016-7606(1967)78[143:BOSBAR]2.0.CO;2 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 Betweeen the northwest-trending Sierra Nevada and the north-northeast-trending ranges that characterize most of the Great Basin section of the Basin and Range province is a belt of confused and divergent topographic forms, which is approximately 50 miles wide and 300 miles long. Along the eastern part of this belt is a topographically low lineament called the Walker Lane.A number of the ranges along the belt have an arcuate form which is controlled by the structure of rocks that are mainly of pre-Cretaceous age; locally, in the southern part of the belt, rocks as young as early Miocene show the arcuate form. The strike of tilted beds, fold axes, and in places elongate plutons, parallels the trend of the arcuate ranges, herein called "oroflexes"—defined as mountain ranges with arcuate trends that result from tectonic bending of the crust.The gross structural pattern of pre-middle Miocene rocks along the belt is a series of sigmoidal bends that suggest gigantic dextral drag. The sigmoidal bends define the oroflexes, facies boundaries, and structural trend lines. These features are cut in places by at least three, and probably five, major northwest-trending faults having right-lateral separations of many miles. Along the strike, the two largest faults seem to die out and the movement is believed to be taken up by bending.The indicated total horizontal displacement by bending and faulting along the belt is 80–120 miles, the Great Basin having moved southeastward relative to the Sierra Nevada. This movement is most likely restricted to the crust, which at some depth is thought to have moved freely over deeper material —either a deeper segment of the crust or the mantle.Available evidence permits the interpretation that the deformation began possibly as early as late Early Jurassic and that the same movement pattern has prevailed ever since. The bending and major strike-slip faulting must have been completed by early or middle Miocene time but much of it may have taken place as long ago as the Jurassic. More recent movements have been restricted to faulting. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.