Tectonic evolution of the early Mesozoic blueschist-bearing Qiangtang metamorphic belt, central Tibet
文献类型：期刊论文
| 作者 | Kapp, P; Yin, A; Manning, CE; Harrison, TM; Taylor, MH; Ding, L |
| 刊名 | TECTONICS
 |
| 出版日期 | 2003-08-28 |
| 卷号 | 22期号:4 |
| 关键词 | Tibet blueschist melange exhumation subduction metamorphic core complex |
| ISSN号 | 0278-7407 |
| DOI | 10.1029/2002TC001383 |
| 文献子类 | Review |
| 英文摘要 | A >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 similar to660degreesC near Shuang Hu (33degreesN, 89degreesE), similar to500degreesC near Rongma (33degreesN,87degreesE), to similar to425degreesC near Gangma Co (34degreesN, 84degreesE). 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 Ar-40/Ar-39 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 &SIM;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. |
| WOS关键词 | DEEP-CRUSTAL STRUCTURE ; NORTHERN TIBET ; CORE COMPLEXES ; CENTRAL CHINA ; OROGENIC BELT ; HIGH-PRESSURE ; ZIRCON GEOCHRONOLOGY ; SOUTHERN CALIFORNIA ; CONTINENTAL-CRUST ; VOLCANIC-ROCKS |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000185254900002 |
| 出版者 | AMER GEOPHYSICAL UNION |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/78253]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Kapp, P |
| 作者单位 | 1.Australian Natl Univ, Inst Adv Studies, Canberra, ACT, Australia 2.Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA 3.Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA 4.Chinese Acad Sci, Inst Geol & Geophys, Lithosphere Tecton Evolut Lab, Beijing 100029, Peoples R China |
| 推荐引用方式 GB/T 7714 | Kapp, P,Yin, A,Manning, CE,et al. Tectonic evolution of the early Mesozoic blueschist-bearing Qiangtang metamorphic belt, central Tibet[J]. TECTONICS,2003,22(4). |
| APA | Kapp, P,Yin, A,Manning, CE,Harrison, TM,Taylor, MH,&Ding, L.(2003).Tectonic evolution of the early Mesozoic blueschist-bearing Qiangtang metamorphic belt, central Tibet.TECTONICS,22(4). |
| MLA | Kapp, P,et al."Tectonic evolution of the early Mesozoic blueschist-bearing Qiangtang metamorphic belt, central Tibet".TECTONICS 22.4(2003). |
入库方式： OAI收割
来源：地质与地球物理研究所
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