【摘要】 望旭山钨矿是北山成矿带东段近年来新发现的一处钨矿床。通过矿床地质特征研究,认为该矿床成因类型为岩浆热液型。为确定矿床的形成时代,重点对含矿花岗岩体开展了LA-ICP-MS锆石U-Pb年代学研究。结果表明,含矿似斑状黑云母二长花岗岩和黑云母二长花岗岩锆石U-Pb测年结果表明其岩浆结晶年龄分别为403.2±2.6Ma和406.8±3.1Ma,时代为早泥盆世。基于岩浆高温热液型钨矿床特征,对近年来我国东部及北山地区这类矿床成矿岩体与成矿时代的统计分析结果表明,该类矿床的成岩年龄与成矿时代相近或高度耦合,结合矿床地质特征将望旭山钨矿的成矿时代也厘定为早泥盆世。结合区域构造演化认为盘陀山-望旭山-鹰嘴红山岩浆岩带的形成与早古生代红柳河-洗肠井洋盆闭合导致明水-旱山地块与敦煌地块碰撞致使陆壳增厚重熔作用有关,为与该期岩浆活动关系密切的钨钼(铜)矿床提供了物质条件。更多还原

【Abstract】 The Wangxushan tungsten deposit is a newly discovered tungsten deposit in the eastern section of the Beishan metallogenic belt. Studying the geological characteristics suggests that it is of a magmatic hydrothermal type. In order to determine the forming time of this tungsten deposit,this work has made LA-ICP-MS zircon U-Pb dating. Results show that the porphyritic biotite monzonite granite and biotite monzonite granite have magma crystallization ages of 403. 2 ± 2. 6 Ma and 406. 8 ± 3. 1 Ma,respectively,as the Early Devonian. Based on the characteristics of magmatic high-temperature hydrothermal tungsten deposits,the statistical analysis of the metallogenic rock mass and metallogenic age of these deposits in eastern China and the Beishan area in recent years shows that the diagenetic age of these deposits is close to or highly coupled with the metallogenic age,and the metallogenic age of the Wangxushan tungsten deposit is also determined as Devonian according to the geological characteristics of the deposit. Combined with regional tectonic evolution,it is considered that the formation of Pangtuoshan-Wangxushan-Yingzuihongshan magmatic belt is related to the thickening and remelting of continental crust caused by the collision between the Mingshui-Hanshan and Dunhuang blocks associated with the closure of the oceanic basin of Hongliuhe-Xichangjing in the Early Paleozoic era,which provided material conditions for the tungsten-molybdenum( copper) deposits closely related to the magmatic activity of this period.更多还原