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dc.contributor.authorChapman, James B.
dc.contributor.authorScoggin, Shane H.
dc.contributor.authorKapp, Paul
dc.contributor.authorCarrapa, Barbara
dc.contributor.authorDucea, Mihai N.
dc.contributor.authorWorthington, James
dc.contributor.authorOimahmadov, Ilhomjon
dc.contributor.authorGadoev, Mustafo
dc.date.accessioned2018-06-04T20:07:03Z
dc.date.available2018-06-04T20:07:03Z
dc.date.issued2018-01-15
dc.identifier.citationChapman, J. B., Scoggin, S. H., Kapp, P., Carrapa, B., Ducea, M. N., Worthington, J., ... & Gadoev, M. (2018). Mesozoic to Cenozoic magmatic history of the Pamir. Earth and Planetary Science Letters, 482, 181-192.en_US
dc.identifier.issn0012821X
dc.identifier.doi10.1016/j.epsl.2017.10.041
dc.identifier.urihttp://hdl.handle.net/10150/627875
dc.description.abstractNew geochronologic, geochemical, and isotopic data for Mesozoic to Cenozoic igneous rocks and detrital minerals from the Pamir Mountains help to distinguish major regional magmatic episodes and constrain the tectonic evolution of the Pamir orogenic system. After final accretion of the Central and South Pamir terranes during the Late Triassic to Early Jurassic, the P amir was largely amagmatic until the emplacement of the intermediate (SiO2 > 60 wt.%), talc-alkaline, and isotopically evolved (-13 to -5 zircon epsilon Hf-(t)) South Pamir batholith between 120-100 Ma, which is the most volumetrically significant magmatic complex in the Pamir and includes a high flux magmatic event at similar to 105 Ma. The South Pamir batholith is interpreted as the northern (inboard) equivalent of the Cretaceous Karakoram batholith and the along-strike equivalent of an Early Cretaceous magmatic belt in the northern Lhasa terrane in Tibet. The northern Lhasa terrane is characterized by a similar high-flux event at similar to 110 Ma. Migration of continental arc magmatism into the South Pamir terrane during the mid-Cretaceous is interpreted to reflect northward directed, low-angle to flat-slab subduction of the Neo-Tethyan oceanic lithosphere. Late Cretaceous magmatism (80-70 Ma) in the Pamir is scarce, but concentrated in the Central and northern South Pamir terranes where it is comparatively more mafic (SiO2 < 60 wt.%), alkaline, and isotopically juvenile (-2 to +2 zircon epsilon Hf-(t)) than the South Pamir batholith. Late Cretaceous magmatism in the Pamir is interpreted here to be the result of extension associated with roll-back of the Neotethyan oceanic slab, which is consistent with similarly aged extension-related magmatism in the Karakoram terrane and Kohistan. There is an additional pulse of magmatism in the Pamir at 42-36 Ma that is geographically restricted (similar to 150 km diameter ellipsoidal area) and referred to as the Vanj magmatic complex. The Vanj complex comprises metaluminous, high-K talc-alkaline to shoshonitic monzonite, syenite, and granite that is adakitic (La/Yb-N = 13 to 57) with low Mg# (35-41). The Vanj complex displays a range of SiO2 (54-75 wt.%) and isotopic compositions (-7 to -3 epsilon Nd-(i), 0.706 to 0.710 Sr-87/Sr-86((i)), -3 to +1 zircon epsilon Hf-(i), 6.0 to 7.6%o zircon delta O-18(VSMOW)), which reflects some juvenile mantle input and subsequent assimilation or mixing with the Central/South Pamir terrane lower crust. The Vanj complex is speculatively interpreted to be the consequence of a mantle drip or small delamination event that was induced by India-Asia collision. The age, geochemistry, outcrop pattern, and tectonic position of the Vanj magmatic complex suggest that it is part of a series of magmatic complexes that extend for >2500 km across the Pamir and northern Qiangtang terrane in Tibet. All of these complexes are located directly south of the Tanymas-Jinsha suture zone, an important lithospheric and rheological boundary that focused mantle lithosphere deformation after India-Asia collision. Miocene magmatism (20-10 Ma) in the Pamir includes: 1) isotopically evolved migmatite and leucogranite related to crustal anataxis and decompression melting within extensional gneiss domes, and; 2) localized intra-continental magmatism in the Dunkeldik/Taxkorgan complex. (C) 2017 Elsevier B.V. All rights reserved.en_US
dc.description.sponsorshipNSF [EAR-1419748, EAR-1450899, EAR-1338583]; Romanian Executive Agency for Higher Education, Research, Development and Innovation [PN-III-P4-ID-PCE-2016-0127]; EarthScope Award for Geochronology Student Researchen_US
dc.language.isoenen_US
dc.publisherELSEVIER SCIENCE BVen_US
dc.relation.urlhttp://linkinghub.elsevier.com/retrieve/pii/S0012821X1730609Xen_US
dc.rights© 2017 Elsevier B.V. All rights reserved.en_US
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectTibeten_US
dc.subjectPamiren_US
dc.subjectKarakoramen_US
dc.subjectdelaminationen_US
dc.subjecthigh-fluxen_US
dc.subjectQiangtangen_US
dc.titleMesozoic to Cenozoic magmatic history of the Pamiren_US
dc.typeArticleen_US
dc.contributor.departmentUniv Arizona, Dept Geoscien_US
dc.identifier.journalEARTH AND PLANETARY SCIENCE LETTERSen_US
dc.description.note24 month embargo; published online: 16 November 2017en_US
dc.description.collectioninformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu.en_US
dc.eprint.versionFinal accepted manuscripten_US
dc.source.journaltitleEarth and Planetary Science Letters
dc.source.volume482
dc.source.beginpage181
dc.source.endpage192


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