【摘要】 前人曾对与水口山矿田成矿关系密切的花岗闪长岩、花岗闪长斑岩、花岗斑岩、英安玢岩等进行了黑云母、全岩K-Ar 法和颗粒锆 U-Pb 稀释法同位素年龄测定,年龄结果介于120～172Via 之间,不同的研究者和不同的方法所测定的结果大不相同。本文对水口山矿区花岗闪长岩中的锆石进行了 SHRIMP U-Pb 年龄的精确测定,结果为163±2Ma(95%可信度,MSWD=1.2)。因此,本文认为:(J)该矿床形成于燕山早期,与华南中生代大规模的成矿作用时间一致,而且与花岗闪长岩有密切的成因联系,成岩与成矿是同时的;(2)结合岩石的微量元素地球化学特征认为,矿床是在中晚侏罗世时地壳处于拉张-减薄构造环境下形成的。更多还原

【Abstract】 Biotite and whole rock K-Ar dating and the single-grained zircon U-Ph dating for granodiorite,granodioritic porphyry, granite porphyry and dacite porphyry related to Shuikoushan ore-field have been previously reporled,but different researchers and different methods give results with great difference from 120Ma to 172Ma.In this paper,we report a precise zircon SHRIMP U-Pb dating for the granodiorite in Shuikoushan ore-field of 163±2Ma(95% confidence,MSWD=1.2).According to this new age, we suggest that:( 1 ) this deposit formed during the early Yanshanian period,which was correspond to the large scale Mesozoic ore-forming time in South China and show a close genetic relation to the granodiorite.The rock-forming time was simultaneous to the ore formation time;(2) combined with the trace element geoehemistry characteristics of the roeks,the results indicate that the deposit formed in Middle and Late Jurassic when the crust was in an extension-thinning structural setting.更多还原