Paleogeographic reconstruction of a late Paleozoic arc collision zone, southern Mongolia

Abstract

Research Article| September 01, 2012 Paleogeographic reconstruction of a late Paleozoic arc collision zone, southern Mongolia Matthew J. Heumann; Matthew J. Heumann † 1ConocoPhillips Company, Houston, Texas, USA †E-mails: matthew.j.heumann@gmail.com; matthew.j.heumann@conocophillips.com Search for other works by this author on: GSW Google Scholar Cari L. Johnson; Cari L. Johnson 2Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112, USA Search for other works by this author on: GSW Google Scholar Laura E. Webb; Laura E. Webb 3Department of Geology, University of Vermont, Burlington, Vermont 05405, USA Search for other works by this author on: GSW Google Scholar Joshua P. Taylor; Joshua P. Taylor 4Department of Earth Sciences, Syracuse University, Syracuse, New York 13244-1070, USA Search for other works by this author on: GSW Google Scholar Undarya Jalbaa; Undarya Jalbaa 5School of Geology and Petroleum Engineering, Mongolian University of Science and Technology, PO Box 520, Ulaanbaatar-46, Mongolia Search for other works by this author on: GSW Google Scholar Chuluun Minjin Chuluun Minjin 5School of Geology and Petroleum Engineering, Mongolian University of Science and Technology, PO Box 520, Ulaanbaatar-46, Mongolia Search for other works by this author on: GSW Google Scholar GSA Bulletin (2012) 124 (9-10): 1514–1534. https://doi.org/10.1130/B30510.1 Article history received: 10 Mar 2011 rev-recd: 02 Feb 2012 accepted: 06 Feb 2012 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 Matthew J. Heumann, Cari L. Johnson, Laura E. Webb, Joshua P. Taylor, Undarya Jalbaa, Chuluun Minjin; Paleogeographic reconstruction of a late Paleozoic arc collision zone, southern Mongolia. GSA Bulletin 2012;; 124 (9-10): 1514–1534. doi: https://doi.org/10.1130/B30510.1 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 Permian sedimentary sequences exposed in southern Mongolia record final closure of the paleo–Asian Ocean and suturing of the terranes of northern China with the southern margin of a vast accretionary complex (the Altaids) in Mongolia. Detrital zircon U-Pb geochronology results presented here are the first of their kind in southern Mongolia. Geologic mapping, stratigraphic interpretations, and provenance data including U-Pb zircon geochronology suggest that sedimentary strata at two localities in southern Mongolia, Bulgan Uul and Nomgon, were once part of the same closing ocean basin. The Upper Permian sedimentary deposits at Bulgan Uul record an upward-shallowing marine succession that is unconformably overlain by Lower Triassic fluvial and alluvial strata. The Bulgan Uul marine succession is composed of distal turbidite fan deposits in the lowest portion of the section, with interbedded sandstone and limestone interpreted as shallow-marine deposits at the top of the section. Exposures of Permian-aged distal turbidite units at Nomgon are similar in stratigraphic architecture, sandstone provenance, and detrital zircon age distributions to those documented at Bulgan Uul. Paleocurrent measurements, sandstone provenance data, and U-Pb ages from detrital zircons collected from both study locations document southeastern transport directions for sediment derived from extinct Carboniferous and Ordovician–Silurian arcs of the southern Altaids. Results are consistent with depositional models for remnant ocean basins and indicate diachronous west-to-east closure of the paleo–Asian Ocean (a northern segment of Paleotethys) in the Late Permian. Finally, basin reconstructions place the coeval turbidite deposits at Nomgon to the southeast of Bulgan Uul during the Late Permian. These correlative turbidite successions at Nomgon are currently northeast of Bulgan Uul, offset by ∼250 km of left-lateral strike-slip faulting across the East Gobi fault zone. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.