Chronology, Geochemistry and Geological Significance of Volcanic Rocks of Dianzhong Formation in Konglong Township Area, Xizang

In this paper, the chronology and geochemistry of the volcanic rocks of the Dianzhong Formation in the Konglong Township area of the central Gangdise are studied. The volcanic rocks of the Dianzhong Formation in Konglong Township Xizang are is a set of acidic, peraluminous, high-potassium, calcium-alkaline rocks, which are rich in large ion lithophile elements(e.g., Rb, K, U), and are depleted of high field strength elements (e.g., Nb, P, Ti), showing obvious characteristics of crust-derived magma, which may be the product of different degrees of remelting of the earth's crust.According to the geochemical characteristics of this volcanic rock, it is speculated that it was formed in a volcanic arc structural environment and has a tendency to transition to syn-collision and intraplate environment. The study samples are all rhyolite tuffs, and one sample obtained LA-ICP-MS zircon U-Pb age of 62.70±0.83 Ma, indicating that its formation age is the Paleogene Paleocene. Through comparative analysis, this set of volcanic rocks erupted earlier in the central and western Gangdise than in the east, confirming the view that the India-Asian collision is time-lapse.