地质学报（英文版）2003，Vol.77Issue(2)：187-193,7.
Cenozoic Adakite-type Volcanic Rocks in Qiangtang,Tibet and Its Significance
Cenozoic Adakite-type Volcanic Rocks in Qiangtang,Tibet and Its Significance
摘要
Abstract
Volcanic rocks in the study area, including dacite, trachyandesite and mugearite, belong to the intermediate-acid, high-K calc-alkaline series, and possess the characteristics of adakite. The geochemistry of the rocks shows that therocks are characterized by SiO2＞59%, enrichment in Al2O3 (15.09-15.64%) and Na2O (＞3.6%), high Sr (649-885 μg/g)and Sc, low Y contents (＜17 μg/g), depletion in HREE (Yb＜1.22 μg/g), (La/Yb)N＞25, Sr/Y＞40, MgO＜3% (Mg#＜0.35),weak Eu anomaly (Eu/Eu*=0.84-0.94), and lack of the high field strength elements (HFSE) (Nb, Ta, Ti, etc.). The Nd andSr isotope data (87Sr/86Sr=0.7062-0.7079, 143Nd/144Nd=0.51166-0.51253, εNd= -18.61-0.02), show that the magmaresulted from partial melting (10%-40%) of newly underplated basaltic lower crust under high pressure (1-4 GPa), and thepetrogenesis is obviously affected by the crust's assimilation and fractional crystallization (AFC). This research will givean insight into the uplift mechanism of the Tibetan plateau.关键词
Cenozoic/lower crust/high-K calc-alkaline volcanic rock/underplating/partial melting/uplift of plateau/Qiangtang/TibetKey words
Cenozoic/lower crust/high-K calc-alkaline volcanic rock/underplating/partial melting/uplift of plateau/Qiangtang/Tibet分类
天文与地球科学引用本文复制引用
LIU Shen,HU Ruizhong,FENG Caixia,CHI Xiaoguo,LI Cai,YANG Rihong,WANG Tianwu,JIN Wei..Cenozoic Adakite-type Volcanic Rocks in Qiangtang,Tibet and Its Significance[J].地质学报（英文版）,2003,77(2):187-193,7.基金项目
This work was supported jointly by "the Ninth Five-Year Plan" key basic research program (Grant No. 9501101-5), the Project of Knowledge Innovation sponsored by the Chinese Academy of Sciences (Grant No. KZCX2-102),and the National Outstanding Young Scien （Grant No. 9501101-5）
