XIKUANGSHAN MICA-PLAGIOCLASE LAMPROPHYRE AND ITS GRANITE INCLUSIONS,HUNAN PROVINCE
Wu Liangshi(Institute of Minetal Deposits, CAGS, Beijing 100039)Hu Xiongwei(Yichang Institute of Geology and Mineral Resources. CAGS. Yichang 443003)
Mica-plagioclase lamprophyre is the only outcropping igneous rock in the Xikuangshan area, belongingto the calc-alkaline series. According to the mineralogy, petrology and isotope geochemistry of the lamprophyre and granite inclusions, it is suggested that there is a concealed intrusive mass in Xikuangshan; themica-plagioclase lamprophyre intruded after granite intrusion. Residual zircon is from the basement rockMiddle Proterozoic Banxi Group and Lingjiaxi Group. It isn' t the product of mantle magma differentiation.So it is inferred that there occurred a Mesozoic geological heat event in the Xikuangshan area.