Gobi-Tianshan connections: Field observations and isotopes from an early Permian arc complex in southern Mongolia

Research Article| November 01, 2012 Gobi-Tianshan connections: Field observations and isotopes from an early Permian arc complex in southern Mongolia R.C. Economos; R.C. Economos † 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA §Current address: Department of Earth and Space Sciences, University of California, Los Angeles, California 90095, USA †E-mail: economos@ucla.edu Search for other works by this author on: GSW Google Scholar S.R. Paterson; S.R. Paterson 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Search for other works by this author on: GSW Google Scholar L.O. Said; L.O. Said 2Department of Geology, School of Geology and Petroleum Engineering, Mongolian University of Science and Technology, Ulaanbaatar 210646, Mongolia Search for other works by this author on: GSW Google Scholar M.N. Ducea; M.N. Ducea 3Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA4Universitatea Bucuresti, Facultatea de Geologie si Geofizica, Bucuresti 010041, Romania Search for other works by this author on: GSW Google Scholar J.L. Anderson; J.L. Anderson 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA Search for other works by this author on: GSW Google Scholar A.J. Padilla A.J. Padilla 5Department of Earth and Environmental Science, Vanderbilt University, Nashville, Tennessee 37240, USA Search for other works by this author on: GSW Google Scholar Author and Article Information R.C. Economos §Current address: Department of Earth and Space Sciences, University of California, Los Angeles, California 90095, USA † 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA S.R. Paterson 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA L.O. Said 2Department of Geology, School of Geology and Petroleum Engineering, Mongolian University of Science and Technology, Ulaanbaatar 210646, Mongolia M.N. Ducea 3Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA4Universitatea Bucuresti, Facultatea de Geologie si Geofizica, Bucuresti 010041, Romania J.L. Anderson 1Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA A.J. Padilla 5Department of Earth and Environmental Science, Vanderbilt University, Nashville, Tennessee 37240, USA †E-mail: economos@ucla.edu Publisher: Geological Society of America Received: 26 Apr 2010 Revision Received: 22 Mar 2012 Accepted: 16 Apr 2012 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2012 Geological Society of America GSA Bulletin (2012) 124 (11-12): 1688–1701. https://doi.org/10.1130/B30324.1 Article history Received: 26 Apr 2010 Revision Received: 22 Mar 2012 Accepted: 16 Apr 2012 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation R.C. Economos, S.R. Paterson, L.O. Said, M.N. Ducea, J.L. Anderson, A.J. Padilla; Gobi-Tianshan connections: Field observations and isotopes from an early Permian arc complex in southern Mongolia. GSA Bulletin 2012;; 124 (11-12): 1688–1701. doi: https://doi.org/10.1130/B30324.1 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 The Tianshan orogen, in the southern Central Asian orogenic belt, consists of continental fragments stitched together during mid- to late Paleozoic arc magmatism generated by the closure of the paleo–Asian Ocean. Controversy persists regarding the timing of final structural amalgamation of the region and therefore whether Permian magmatism was generated in a subduction or intraplate environment. Based on new field mapping, zircon U-Pb geochronology, and isotope data from the 295–290 Ma Gobi-Tianshan intrusive complex in southwestern Mongolia, we argue that this complex is a voluminous intermediate batholith generated by subduction and that it is related to plutons of similar age and character in Tianshan tectono-magmatic belts to the west. In the study area, as well as in Carboniferous and Permian plutons across the Tianshan, mantle isotopic signatures remain consistently primitive. Permian plutons show an increase in radiogenic Sr with no concurrent decrease in radiogenic Nd, which may be due to the influence of subducting continental sediment in the early Permian. This model explains the transitional nature of magmatic compositions and structures in the Gobi-Tianshan intrusive complex. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.