Re-Os dating of molybdenite from the Lietinggang iron polymetallic deposit of Xizang and its geological significance

Among lots of polymetallic deposits, the Lietinggang deposit in the Lhunzhub Basin of Xizang is one of the deposits with best industrial value and exploration prospect. It is a typical deposit where Fe, Cu, Mo, Pb and Zn have been found. High precision Re-Os dating was conducted for 10 molybdenite samples for determining the mineralization age of the Lietingang deposit. It is for the first time that the high precision mineralization age of the deposit has been obtained. The test result indicates that the Re-Os model ages vary in the range of (60.97+0.92) Ma-(63.19+0.93) Ma, and the isochron age is (62.28+0.66) Ma, with MSWD being 0.74. During the main Indosinian collision period in the Gangdise belt, the deposit was formed in the Paleocene. The Re values of 8 pieces of molybdenite are mainly concentrated in the range of 0.54×10^-6-84.72×10^-6. The sources of the ore-forming materials were mainly from the Earth's mantle and crust. The determination of the ore-forming epoch and metallogenic material of the Lietinggang deposit is of great significance for the regional ore-prospecting prognosis of early Paleocene iron-polymetallic deposits.