Geochemical features and tectonic setting of Yanshanian high-K calc-alkaline granite in the Songxi-Shenglishan area, northern Rutog, Tibet,China.

Granodiorite and biotite monzogranite in the Songxi-Shenglishan area,north Qiangtang,Tibet,belongs to a high- K calc-alkaline series.The rocks are HREE-depleted.The LREE/HREE ratios of granodiorite range from 8.67 to 33.08, with an average of 16.62,and those of biotite monzogranite range from 9.16 to 30.97,with an average of 21.76.The Eu anomalies of the two types of rock are neither pronounced.For the trace elements,the rocks are enriched in Rb and Th and depleted in Ba,Sr,Zr and Ti.Granodiorite and biotite monzogranite generally exhibit the features of I-type granite and their tectonic environment is very likely to be related to collision between the Gangdise and Qiangtang blocks during the Late Jurassic to Early Cretaceous.