Full-Text Search:
Home|Journal Papers|About CNKI|User Service|FAQ|Contact Us|中文
《Geochimica》 2018-02
Add to Favorite Get Latest Update

LA-ICP-MS zircon U-Pb dating,geochemical characteristics and geological significance of Early Cretaceous granites in the Serirong area of north-central Gangdese,Tibet

QIN Song;SUN Chuan-min;ZHANG Jian-bo;ZHANG Wei;DING Dai-guo;NIMA Ci-ren;College of Earth Sciences, Chengdu University of Technology;Regional Geological Survey Team, Sichuan Bureau of Geology and Mineral Exploration and Development;No.2 Geological Party, Xizang Bureau of Geology and Mineral Exploration and Development;  
The Cuijueguo and Hankongda granites are found in the Serirong area, in the eastern section of the Longgaer-Gongbujiangda uplift, north-central Gangdese; they mainly comprise biotite adamellite, and biotite granite. The Hankongda granites have been analyzed using the LA-ICP-MS zircon U-Pb techniques; their U-Pb age is(136.0±1.4) Ma, which is similar to that of the Cuijueguo granite, representing large-scale middle-acid magmatic activity of the Early Cretaceous in the region. The two granites belong to the shoshonites to high-K calc-alkaline and strongly peraluminous S-granite series, based on the analysis of the petrology and major elements. They display typical geochemical signatures of post-collisional granites, including the depletion of Sr, P, Ti, and Nb. The two granites have high Th abundance values(the vast majority are more than 20), indicating their source to be crustal material. Both granites show significant differentiation between LREE and HREE with a right-leaning pattern, reflecting high maturity of the crust. Based on the geochemical analysis, the trace element discrimination diagrams for tectonic interpretation, and regional tectonic evolution, it can be established that the Serirong granites have been formed after the main orogenic event in the Bangonghu-Nujiang suture, in a post-collisional tectonic setting transitioning from the compressional system to the tensional system. They are derived from the partial melting of the metamorphosed basement of psammitolite from Nyainqentanglha Group. The discovery and age determination of these two granites in the Serirong area constrains of the post-collisional tectonic setting in the north-central Gangdese to before 136.0~139.2 Ma.
【Fund】: 中国地质调查局项目(1212011221077);; 国家自然科学基金(41272046)
【CateGory Index】: P534.53;P588.121
Download(CAJ format) Download(PDF format)
CAJViewer7.0 supports all the CNKI file formats; AdobeReader only supports the PDF format.
©2006 Tsinghua Tongfang Knowledge Network Technology Co., Ltd.(Beijing)(TTKN) All rights reserved