LA-ICP-MS Zircon U-Pb Dating of Allgovite in the Bangpu Molybdenum(Copper) Deposit in Tibet and Its Geological Significance

The Bangpu porphyry Mo(Cu) deposit is located in the eastern part of the Gangdise metallogenic belt in Tibet,near the Jiama copper polymetallic deposit and the Qulong porphyry Cu deposit.The magma invasion is of high frequency in this area,and varied kinds of intrusions were developed in different periods.Researches on the allgovite in the northern part of the Bangpu ore district are very insufficient.The age of allgovite was obtained in this deposit.According to LA-ICP-MS analysis of the zircon U-Pb age precision of the allgovite,19 zircons from allgovite yielded the weighted average 206 Pb/238 U age of 15.21±0.29 Ma(MSWD=9.6,N=19),suggesting Miocene magma emplacement in Gangdise belt,and the age is consistent with that of allgovite in the Jiama porphyry deposit.Regional ore-forming regularity study shows that the Bangpu porphyry Mo(Cu) polymetallic deposit is in accord with the regional porphyry deposits such as Jiama and Qulong in the ore-forming and rock-forming age,suggesting that this deposit has the same geochemical dynamic background deep process as Jiama,Qulong and some other ore deposits.