GEOLOGY AND GENESIS OF THE HERCYNIAN-INDOSINIAN GRANITIC ROCKS IN ZHULUKE AREA,WESTERN LIAONING PROVINCE,CHINA

The granitic rocks in Zhuluke area,Western Liaoning,emplaced during Late Hercynian-Indosinian cycle,with Rb Sr isochronal dating age of 226.8~260 Ma.According to the classification principles of lithological lineage units,the granitic rocks may be divided (in descending order)into Zhongguanyingzi (including Xiyao and Erdaogou units)and Yushulinzi (including Litaizi,Nianpanshan and Aobaoshan units)super-units.The magma evolved from intermediate to acid in nature.Genetically,they are the transition between I-type and S-type granites,formed in the tectonic environment of late orogenic epoch,directly related to the South Mongolian compound orogeny.