新疆阿尔泰成矿带可可塔勒花岗岩体锆石LA-ICP-MS U-Pb年龄及其地质意义

新疆阿尔泰成矿带花岗岩发育,其中很多花岗岩与成矿作用有着密切的联系,特别是400Ma左右的岩浆活动是阿尔泰地区一次重要的岩浆成矿活动,阿尔泰许多金属矿床与这一时期的岩浆构造作用有关。本次研究的出露于可可塔勒铅锌矿区的黑云母花岗岩体,其锆石LA-ICPMS U-Pb年龄为(401.8±1.5)Ma,表明可可塔勒花岗岩是阿尔泰成矿带400Ma左右发生的一次重要岩浆构造作用的产物,该黑云母花岗岩体侵入于矿区下泥盆统康布铁堡组火山岩地层中,岩体与围岩接触带附近的围岩蚀变明显,该黑云母花岗岩的侵入以及其后期的岩浆热液活动可能对区内成矿物质的活化、迁移、富集、成矿具有一定的贡献。

LA-ICP-MS zircon U-Pb age of Keketale granite body in Altay metallogenic belt,Xinjiang,and its geological implications

A great number of granites that widely exposed in Altay metallogenic belt,Xinjiang,are closely related to mineralizations,especially,the magmatic activity with an age about 400Ma is an important magmatic mineralization event in Altay region,and many metal deposits are closely related with the magmatism-tectonism happened during this period in the region.This paper studies on the Keketale biotite granite body outcropped in Keketale lead-zinc mineral district.The granite body yields a LA-ICP-MS zircon U-Pb age of 401.8 ± 1.5 Ma,which means that the Keketale granite body is the product of an important magmatism-tectonism happened in the period about 400 Ma in Altay metallogenic belt.The biotite granite body intruded into the volcanic strata of lower Devonian Kangbutiebao group,and there are obvious alterations of wall-rocks shown in the contact zone between the granite body and wall rocks.The intrusion of the biotite granite body and its magmatic thermal activity might contribute to activation,migration,concentration and mineralization of the metallogenic materials in this area.