论文部分内容阅读
乌拉山—大青山成矿带为华北板块北缘重要的金成矿带,其中蕴含哈达门沟—柳坝沟大型金(钼)矿田,金(钼)矿床成矿时代和构造背景一直存在争议,长期被认为是中生代构造岩浆活动产物,最近在哈达门沟金矿床深部发现了与金共生的石英脉型和钾化蚀变岩型钼矿化,笔者等利用Re-Os同位素分析方法,首次对与含金黄铁矿共生的辉钼矿进行了年代学研究。4件辉钼矿Re-Os同位素等时线年龄为386.6±6.1M a(MSWD=1.18),加权平均年龄为386.4±2.7M a(MSWD=0.55),初始187Os值为-0.02±0.41。根据以上年龄值,并且结合其它地质证据,可以推测,哈达门沟地区金矿化发生的事件可追溯到早泥盆世,属海西早期构造—岩浆活动事件。上述数据的取得,对重新认识该区金矿成矿作用及区域地质演化历史有着重要的理论和实际意义。
The Wulashan-Daqingshan metallogenic belt is an important gold metallogenic belt along the northern margin of the North China Plate, which contains the Hadarmen-Liugasigou gold (molybdenum) and gold (molybdenum) ore deposits. The mineralization age and tectonic setting have been controversial Has been considered as the Mesozoic tectonic magmatism for a long time. Recently, quartz vein type and potash altered rock type molybdenum mineralization associated with gold were found in the deep Hadadougou gold deposit, and the author used the Re-Os isotope analysis method for the first time The chronology of molybdenite symbiotic with gold-bearing pyrite was studied. The Re-Os isotopic isochron age of 38 molybdenite was 386.6 ± 6.1Ma (MSWD = 1.18). The weighted mean age was 386.4 ± 2.7Ma (MSWD = 0.55). The initial 187Os value was -0.02 ± 0.41. Based on the above age values, combined with other geological evidence, it can be inferred that the occurrence of gold mineralization in the Hadarmen ditch region can be traced back to the Early Devonian, an event of the Hercynian tectono-magmatic activity in the early period. The above data acquisition has important theoretical and practical significance to re-understand the gold mineralization and the history of regional geological evolution in this area.