GEOLOGY AND GENESIS OF XITIAN SUPER-LARGE BASALT DEPOSIT IN HUAYINGSHAN FOLD BELT, EASTERN SICHUAN

Through field survey and petrographic observation under microscope, combined with geochemical analysis for major and trace elements, the paper studies the geological characteristics of Xitian super-large fiber-used basalt deposit in Linshui County of Sichuan Province, and analyzes the industry indexes of ores and deposit genesis. The results show that the deposit is located in the east wing of Huayingshan anticline of eastern Sichuan fold belt, and the orebody is occurred in stratoid in the Upper Permian Emeishan basalt formation, with the ore reserves about 15.94 Mt, reaching the super-large size. The geochemistry of major elements indicate that the Xitian basaltic magma belongs to high Ti, high K calc alkaline-calc alkaline series. The geochemical characteristics of trace and rare earth elements are similar to those of the regional high Ti Emeishan basalt and OIB-type basalt. The Xitian basalt is the outer zone component of the Emeishan large igneous province, formed in the intraplate tectonic environment, with the magmatic evolution from OIB source area and basically no hybridization of crustal materials, which is of mantle plume origin. The columnar jointed, massive and vesicular basalts in the deposit can be used for fiber drawing production.