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dc.contributor.authorKapp, Paul
dc.contributor.authorYin, An
dc.contributor.authorManning, Craig E.
dc.contributor.authorHarrison, T. Mark
dc.contributor.authorTaylor, Michael Halford
dc.contributor.authorDing, Lin
dc.date.accessioned2015-03-18T19:46:20Z
dc.date.available2015-03-18T19:46:20Z
dc.date.issued2003-08-28
dc.identifier.citationKapp, P., A. Yin, C. E. Manning, T. M. Harrison, M. H. Taylor, and L. Ding (2003), Tectonic evolution of the early Mesozoic blueschist-bearing Qiangtang metamorphic belt, central Tibet, Tectonics, 22, 1043, http://dx.doi.org/10.1029/2002TC001383, 4.en_US
dc.identifier.urihttp://hdl.handle.net/1808/17114
dc.descriptionThis is the published version. Copyright 2003 American Geophysical Union. All Rights Reserved.en_US
dc.description.abstractA >500-km-long east-west trending metamorphic belt in the Qiangtang terrane of central Tibet consists of tectonic melange that occurs in the footwalls of Late Triassic–Early Jurassic domal low-angle normal faults. The melange is comprised of a strongly deformed matrix of metasedimentary and mafic schists that encloses lesser-deformed blocks of metabasites, Carboniferous–Triassic metasedimentary rocks, and early Paleozoic gneiss. Both the blocks and melange matrix exhibit greenschist, epidote-blueschist, and locally, epidote-amphibolite facies mineral assemblages. Thermobarometry reveals that the metamorphic belt experienced pressures of >10 kbar. Maximum equilibration temperatures for mafic schists in the melange matrix decrease from east to west, from ∼660°C near Shuang Hu (33°N, 89°E), ∼500°C near Rongma (33°N, 87°E), to ∼425°C near Gangma Co (34°N, 84°E). Equilibration at consistently high pressures over a large range of temperatures is compatible with metamorphism of Qiangtang melange within a low-angle subduction zone beneath a continental margin. Coupled structural, thermobarometric, and 40Ar/39Ar studies suggest that Qiangtang melange was exhumed in an intracontinental setting from depths of >35 km to upper crustal levels in <12 Myr by Late Triassic–Early Jurassic crustal-scale normal faulting. Detrital zircons from metasandstones within the melange matrix yield U-Pb ion-microprobe ages that range from early Paleozoic to Early Archean, and could have been sourced from terranes to the north of the Jinsha suture. Our results support a model in which Qiangtang melange was underthrust ∼200 km beneath the Qiangtang terrane during early Mesozoic flat-slab southward subduction of Paleo-Tethyan oceanic lithosphere along the Jinsha suture. This model predicts that significant portions of the central Tibetan continental mantle lithosphere were removed during early Mesozoic low-angle oceanic subduction and that the present-day central Tibetan deeper crust includes large volumes of underthrust early Mesozoic melange.en_US
dc.publisherAmerican Geophysical Unionen_US
dc.subjectTibeten_US
dc.subjectblueschristen_US
dc.subjectmelangeen_US
dc.subjectexhumationen_US
dc.subjectsubductionen_US
dc.subjectmetamorphic core complexen_US
dc.titleTectonic evolution of the early Mesozoic blueschist-bearing Qiangtang metamorphic belt, central Tibeten_US
dc.typeArticle
kusw.kuauthorTaylor, Michael Halford
kusw.kudepartmentGeologyen_US
dc.identifier.doi10.1029/2002TC001383
kusw.oaversionScholarly/refereed, publisher version
kusw.oapolicyThis item does not meet KU Open Access policy criteria.
dc.rights.accessrightsopenAccess


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