Distribution and provenance of the middle Miocene Eagle Mountain Formation, and implications for regional kinematic analysis of the Basin and Range province

Abstract

Research Article| April 01, 2001 Distribution and provenance of the middle Miocene Eagle Mountain Formation, and implications for regional kinematic analysis of the Basin and Range province Nathan A. Niemi; Nathan A. Niemi 1Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA Search for other works by this author on: GSW Google Scholar Brian P. Wernicke; Brian P. Wernicke 1Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA Search for other works by this author on: GSW Google Scholar Robert J. Brady; Robert J. Brady 1Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA Search for other works by this author on: GSW Google Scholar Jason B. Saleeby; Jason B. Saleeby 1Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA Search for other works by this author on: GSW Google Scholar George C. Dunne George C. Dunne 2Department of Geological Sciences, California State University, 18111 Nordhoff Street, Northridge, California 91330, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Nathan A. Niemi 1Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA Brian P. Wernicke 1Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA Robert J. Brady 1Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA Jason B. Saleeby 1Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA George C. Dunne 2Department of Geological Sciences, California State University, 18111 Nordhoff Street, Northridge, California 91330, USA Publisher: Geological Society of America Received: 30 Mar 2000 Accepted: 19 Apr 2000 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2001) 113 (4): 419–442. https://doi.org/10.1130/0016-7606(2001)113<0419:DAPOTM>2.0.CO;2 Article history Received: 30 Mar 2000 Accepted: 19 Apr 2000 First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Nathan A. Niemi, Brian P. Wernicke, Robert J. Brady, Jason B. Saleeby, George C. Dunne; Distribution and provenance of the middle Miocene Eagle Mountain Formation, and implications for regional kinematic analysis of the Basin and Range province. GSA Bulletin 2001;; 113 (4): 419–442. doi: https://doi.org/10.1130/0016-7606(2001)113<0419:DAPOTM>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 Conglomeratic strata from middle Miocene sections in the central Resting Spring Range and nearby Eagle Mountain, California, contain a clast assemblage including marble, orthoquartzite, fusulinid grainstone, and coarse (∼1 m) monzogabbro, interstratified with tephras yielding laser-fusion 40Ar/39Ar ages of 11.6, 13.4, and 15.0 Ma. Petrographic and geochronologic evidence ties the clast assemblage to a source area in the southern Cottonwood Mountains, California, >100 km west-northwest of their present location. In the upper 100 m of the Resting Spring Range section, conglomerates are derived almost exclusively from the southern Cottonwoods source, and sandstone modes are as much as 50% angular plagioclase derived from the monzogabbro. The lack of dilution of this detritus by other sources and sedimentary features in both sections indicate (1) that deposition occurred on an alluvial fan with a north- northeast paleoslope and (2) that transport of the gravels by sedimentary processes was probably <20 km north-northeast, in a direction normal to the present azimuth to their source. Therefore, we interpret most or all of the net east-southeast transport as a result of extensional and strike-slip faulting between the Cottonwood Mountains and the Resting Spring Range since 11–12 Ma. Restoration of these deposits to a position 10–20 km north-northeast of the eastern margin of the monzogabbro source (east margin of the Hunter Mountain batholith) yields a net tectonic displacement of the Cottonwood Mountains relative to the Resting Spring Range of 104 km N67°W. This result confirms previous reconstructions based on the restoration of isopachs in the Cordilleran miogeocline, pre-Cenozoic structural features, and other proximal Tertiary deposits in the region. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.