Abstract:The Tongshan intermediate felsic rocks emplaced in conjunction area between Yangtze block and Cathaysian block, i.e. in the eastern part of the Qinhang conjunction areas. Tongshan intermediate felsic rocks consist of granite diorite porphyry and quartz diorite porphyrite, accompanied with medium sized skarn copper deposits. The zircons from granite diorite porphyry show distinct zonation structure with high Th/U ratios(0.40~1.07), suggesting that zircons are typical magmatic in origin. LA ICP MS zircon U Pb dating yields an age of 171.0±1.6 Ma(n=15, MSWD=0.16).Major element and trace element characteristics indicate that the intermediate acid intrusive rocks are high K peraluminous aluminous I type granitoid, with strong LREE/HREE fractionation (LaN/YbN=10.53~38.37) and no significant negative Eu anomalies (δEu average of 1.05). Enrichment of large ion lithophile elements (Rb, Ba, Th, U and K) and depletion of Nb, Ta and Ti, low contents of Y (<10.4×10-6) and Yb (<0.93×10-6), high Sr/Y ratio(>26), suggest the rocks are of double geochemical characteristics of arc volcanic rock and adakite. Comprehensive study shows that the intermediate felsic rocks formed at the pressure greater than 1.5 GPa, magmatic source depth was more than 50 km, and the source region composition was rutile rich amphibole eclogite facice rocks, which resulted from partial melting of thickening lower crust with relaxation environment after extension caused by the oblique subduction tectonic of the Paleo Pacific Plate. The ore forming materials were easily extracted and accumulated to form Cu Au deposits from the magmatic melts with adakitic characteristics. Therefore, the Tongshan area has the potential of mineralization and is worth broadening exploration.