The magmatic constraint for Early Triassic lithium-rich green bean rocks in Sichuan Basin and adjacent area

The green bean rocks are rich in lithium element in Sichuan Basin and adjacent area. Many mineralological and chronological research have been conducted, but the research of lithium element metallogenic material source and enrichment mechanism for green bean rocks are weak, and the relations bet ween regional magmatism and lithium metallogeny are unknown. The mineral geochemistry, zircon SHRIMP U-Pb chronology and Lu-Hf isotope of Beibei green bean rocks and compare with that of green bean rocks in Sichuan Basin and adjacent area, which all indicate the lithium content show obvious higher Lithium contents of the bottom of green beans rocks layer than that of the top layer in Sichuan Basin and adjacent area. The original rock for Beibei green bean rocks is rhyolite dacite/dacite, which are derived from the volcanic arc magmatism in the Early Triassic.The age of Beibei green bean rocks is 248 +/- 2Ma. The green bean rocks of Beibei and adjacent area have obvious relations with the southwestern Sanjiang area Early Triassic magnetic activity, maybe the response of Early Triassic intermediate-acidic volcanic magnetic activity of the Sanjiang area . The lithium metallogenic material source of green bean rocks in Sichuan Basin and adjacent area are related to volcanic magmatism and hydrothermal fluids. The sufficient volcanic ash and some metallogenic material source of lithium for the green bean rocks in the Sichuan Basin and Adjacent area derived from the Early Triassic intermediate-acidic volcanic magmatism in southwestern Sanjiang area at an early stage, and then the volcanic ash which was modified by hydrothermal fluid and lead to the further enrichment for lithium,and the lithium-rich green bean rocks are formed by burial diabetes eventually.