粤北瑶岭钨矿成矿相关花岗岩的锆石SHRIMP年龄与^(40)Ar/^(39)Ar成矿年龄及其地质意义

^(40)Ar-^(39)Ar dating of Yaoling tungsten deposit in northern Guangdong Province and SHRIMP U-Pb zircon age of related granites

粤北瑶岭钨矿区存在石英脉型黑钨矿和矽卡岩型白钨矿两种成矿类型,与石英脉型黑钨矿成矿同期形成的白云母的40Ar/39Ar年龄为(149.44±0.73)Ma,与华南中生代燕山期大规模的W、Sn成矿作用的年龄一致,代表石英脉型黑钨矿的成矿年龄。与石英脉型黑钨矿成矿相关的隐伏灰白色黑云母花岗岩的SHRIMP锆石年龄为(158±2)Ma,与矽卡岩型白钨矿成矿相关的浅肉红色白基寨黑云母花岗岩的SHRIMP锆石年龄为(158±1)Ma,这两个花岗岩体的年龄完全相同,代表了与瑶岭钨矿成矿相关的花岗岩结晶年龄。白基寨花岗岩中存在年龄为182.3～189.8Ma的继承性岩浆锆石核,矿区隐伏黑云母花岗岩中存在年龄为400.9～428.5Ma的继承性锆石核,表明与成矿相关花岗岩的原岩含有加里东期和燕山早期火成岩的成分。

The Yaoling tungsten deposit has two types of tungsten mineralization,i.e.,wolframite-quartz veins and scheelite skarn.The 40Ar/39Ar age of muscovite formed in the ore-forming period of wolframite-quartz veins is（149.44±0.73）Ma,consistent with large-scale tungsten and tin mineralization in Mesozoic Yanshanian period in South China,and this age represents the ore-forming time of wolframite-quartz vein deposits.The SHRIMP zircon age of the buried biotite plagioclase granite body related to mineralization of wolframite-quartz veins is（158±2）Ma,whereas the SHRIMP zircon age of Baijizhai biotite granite body related to mineralization of scheelite skarn is（158±1）Ma.The two ages are almost identical and represent crystallization age of the granite related to tungsten mineralization.In the ore district,there exist inherited zircon cores with ages of 182.3～189.8 Ma and 400.9～428.5 Ma respectively in Baijizhai biotite granite and buried biotite plagioclase granite,implying that the protolith of granites related to mineralization has igneous rock components of both early Yanshanian period and Caledonia period.