Geochemistry, Geochronology, Sr-Nd Isotopic Compositions of Jiang Tso Ophiolite in the Middle Segment of the Bangong- Nujiang Suture Zone and Their Geological Significance

• Published in: Acta geologica Sinica (Beijing) Vol. 89; no. 2; pp. 389 - 401
• Main Authors: Qiangtai, HUANG, Jianfeng, LI, Zhourong, CAI, Lianze, XIA, Yajuan, YUAN, Huichuan, LIU, Bin, XIA
• Format: Journal Article
• Language: English
• Published: Richmond Blackwell Publishing Ltd 01.04.2015; Wiley Subscription Services, Inc; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou 510006, Guangdong, China%Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, Guangdong, China%School of Earth Science and Geological Engineering, Sun Yat-sen University, Guangzhou 510275,Guangdong, China; School of Marine sciences, Sun Yat-Sen University, Guangzhou 510006, Guangdong, China; Key Laboratory of Offshore Oil Exploration and Development, Guangdong University, Guangzhou 510006, Guangdong, China
• Edition: English ed.
• Subjects: Depletion; Enrichment; Gabbro; Geochemistry; Mantle; Segments; SHRIMP U-Pb dating; Sr-Nd isotopes; SR-Nd同位素; Strontium; Sutures; tectonic environment; Tibet; 中段; 同位素组成; 地球化学; 地质年代学; 地质意义; 怒江缝合带; 蛇绿岩; Tethys Sea; ISW, India; SHRIMP U-Pb dating; Sr-Nd isotopes; geochemistry; Tibet; tectonic environment
• ISSN: 1000-9515; 1755-6724
• DOI: 10.1111/1755-6724.12437

The Jiang Tso ophiolite, situated in the middle segment of the Bangong- Nujiang Suture Zone, is a part of the easternmost Qieli Lake ophiolite subzone and is close to the south of Pung Lake ophiolite. The rock association of Jiang Tso ophiolite is relatively complete and is mainly composed of metamorphic peridotite, gabbro and diabase. Comparing with N-MORB, the ophiolite is high in Mg and low in Ti, K, Na, P, and is depleted in Nb, Ta, Hf, Th and enriched in Rb, Sr and Ba. Geochemical characteristics of the Jiang Tso ophiolite indicate it is of a supra-subduction zone type formed in the spreading ridge of back arc basin. The SHRIMP U-Pb dating of zircons from the gabbro yielded a weighted average age of 188.1±4.1 Ma （MSWD=1.4）, indicating the Jiang Tso ophiolite was formed in the late stage of early Jurassic. The Sr, Nd isotopic compositions show that the Tethyan mantle domain is the depleted mantle （DM）, with enriched mantle domain II （EMII）. They have the same Sr, Nd isotopic composition with the India Ocean MORB type.