内蒙古东部得耳布尔铅锌矿床安山岩的形成环境和岩浆热液演化史:锆石U-Pb定年

得耳布尔铅锌矿床是一座与火山作用有关的中型以上热液脉型多金属矿床,产于大兴安岭西坡中段得尔布干成矿带北段。笔者对矿区内发育的赋矿围岩安山岩开展了单颗粒锆石U-Pb测年,实验结果揭示:安山岩的岩浆期为144~139 Ma(加权平均年龄为141.6±1.8 Ma,MSWD=0.69,n=6)、岩浆热液期为136~132 Ma(加权平均年龄为134.7±5.7 Ma,MSWD=1.3,n=3)及热液期为129~128 Ma(加权平均年龄为128.4±2.5 Ma,MSWD=0.074,n=3),火山岩浆-热液作用经历了至少13 Ma;成岩作用发生在中国东部早白垩世岩石圈减薄期。

Forming environment and magmatic-hydrothermal evolution history of andesite in Deerbuer lead-zinc deposit of eastern Inner Mongolia:Zircon U-Pb dating

Deerbuer lead- zinc deposit is located in northern Derbugan metallogenic belt on the western slope of the Great Xing'an Ｒange， and is a medium- sized polymetallic deposit in hydrothermal vein type， related to volca- nism in genesis． The authors carried on the zircon U- - Pb dating for the andesite，ore- hosting rock in the Deerbuer mining area． It shows that the age of the magmatic stage is 144 ～139 Ma (weighted mean age is 141. 6 ±1. 8 Ma， MSWD =0. 69，n =6)，the age of the magmatic- hydrothermal stage is 136 ～132 Ma (weighted mean age is 134. 7 ±5. 7 Ma，MSWD =1. 3，n =3) and the hydrothermal stage is 129 ～128 Ma (weighted mean age is 128. 4 ±2. 5 Ma，MSWD =0. 074，n =3)． The above results indicate that the volcanism of magmatic- hydrothermal experienced for at least 13 Ma，and the diagenesis took place during the lithosphere thinning stage in the Early Cretaceous in eastern China．