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Isotopic and structural constraints on the location of the Main Central thrust in the Annapurna Range, central Nepal Himalaya

2005; Geological Society of America; Volume: 117; Issue: 7 Linguagem: Inglês

10.1130/b25646.1

1943-2674

Aaron J. Martin, Peter G. DeCelles, George E. Gehrels, P. Jonathan Patchett, C. E. Isachsen,

High-pressure geophysics and materials

Research Article| July 01, 2005 Isotopic and structural constraints on the location of the Main Central thrust in the Annapurna Range, central Nepal Himalaya Aaron J. Martin; Aaron J. Martin 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar Peter G. DeCelles; Peter G. DeCelles 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar George E. Gehrels; George E. Gehrels 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar P. Jonathan Patchett; P. Jonathan Patchett 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar Clark Isachsen Clark Isachsen 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Aaron J. Martin 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Peter G. DeCelles 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA George E. Gehrels 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA P. Jonathan Patchett 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Clark Isachsen 1Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Publisher: Geological Society of America Received: 25 May 2004 Revision Received: 19 Oct 2004 Accepted: 02 Jan 2005 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2005) 117 (7-8): 926–944. https://doi.org/10.1130/B25646.1 Article history Received: 25 May 2004 Revision Received: 19 Oct 2004 Accepted: 02 Jan 2005 First Online: 02 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 Aaron J. Martin, Peter G. DeCelles, George E. Gehrels, P. Jonathan Patchett, Clark Isachsen; Isotopic and structural constraints on the location of the Main Central thrust in the Annapurna Range, central Nepal Himalaya. GSA Bulletin 2005;; 117 (7-8): 926–944. doi: https://doi.org/10.1130/B25646.1 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 Five isotope-enhanced geologic transects in the southern Annapurna Range of central Nepal elucidate structural geometries near the Main Central thrust. Whole-rock Nd isotopes and U-Pb ages of detrital zircons unambiguously distinguish Greater Himalayan (hanging wall) and Lesser Himalayan (footwall) metasedimentary rocks. ϵNd(0) values for lower Lesser Himalayan rocks typically range from −20 to −26, whereas Greater Himalayan rocks usually have ϵNd(0) values of −19 to −12. Lower Lesser Himalayan rocks yield detrital zircons with an age peak at ca. 1880 Ma and no detrital zircons younger than ca. 1550 Ma. In contrast, Greater Himalayan rocks yield detrital zircons with a prominent broad peak of ages at ca. 1050 Ma and no detrital zircons younger than ca. 600 Ma. The protolith boundary between Greater and Lesser Himalayan rocks is up to 1 km farther south than usually mapped on the basis of lithology. Field and microstructural observations indicate the presence of a top-to-the-south ductile shear zone superimposed on this boundary, confirming this shear zone as the Main Central thrust. No evidence exists for large-scale structural mixing of Greater and Lesser Himalayan rocks along the Main Central thrust in the Annapurna Range. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.