西藏查个勒铜铅锌矿成岩成矿时代及意义

西藏查个勒铜铅锌矿在念青唐古拉铜铅锌银成矿带已发现的铜多金属矿床中处于最西端, 矿区同时存在接触交代-充填型铜铅锌矿化和斑岩型铜钼矿化.锆石LA-ICP-MS U-Pb和辉钼矿Re-Os测试表明, 矿区两种类型矿化近乎同时形成, 北部与铜铅锌矿化相关的花岗斑岩成岩时代为62.1±1.1 Ma(MSWD=2.7), 南部与铜钼矿化相关的花岗斑岩成岩时代为63.28±0.86 Ma(MSWD=3.2), 南部辉钼矿Re-Os等时线年龄为61.49±0.60 Ma(MSWD=1.5), 是在雅鲁藏布江洋盆北向俯冲后的同碰撞期形成的.该成果完善和充实了念青唐古拉铜铅锌银成矿带碰撞期成矿的时间演化序列, 且使该带规模在原有基础之上向西延伸了200 km(谢通门县青都-昂仁县查个勒), 显示该带为一条贯穿东西、以碰撞期成矿为主、长大于800 km的巨型铜铅锌银成矿带, 并为继续在此带向西寻找该类型矿床提供了重要依据. 

Geochronology of Magmatic Intrusions and Mineralization of Chagele Copper-Lead-Zinc Deposit in Tibet and Its Implications

Tibet chagele Copper-lead-zinc deposit is in the west end of those copper-polymetallic deposits found in Nyainqentanglha copper-lead-zinc-silver metallogenic belt, and there are two types of mineralization in the mining area, namely, copper-lead-zinc mineralization of the contact metasomatic filling and copper-molybdenum mineralization of porphyry. The zircon LA-ICP-MS U-Pb age and molybdenite Re-Os age show that two types of mineralization almost formed at the same time. The petrogenic age of the northern granite-porphyry related to copper-lead-zinc-silver mineralization is 62.1±1.1 Ma (MSWD=2.7), the southern granite-porphyry which is related to copper-molybdenum mineralization is 63.28±0.86 Ma (MSWD=3.2), and the molybdenite Re-Os age of the south is 61.49±0.60 Ma (MSWD=1.5), which formed at syn-collision stage after northward subduction of the Yarlung Zangbo oceanic basin. This study improves and enriches the time evolvement sequence and genesis of the collision metallogenic stage in Nyainqentanglha copper-lead-zinc-silver mineralization belt, and it also extends westwards its length by 200 km (Qingdu in Xietongmen-Chagele in Angren). As a result, it is found to be a huge copper-lead-zinc-silver metallogenic belt, extending in the direction of east-west more than 800 km, with deposits mainly formed in collection stage. In addition, this study provides important basis to the prospecting of the same deposits in the west of the belt.