西藏班公湖—怒江成矿带斑岩-浅成低温热液型矿床岩浆作用与成矿:以改则县东窝东铜多金属矿床为例

发布时间：2018-04-28 04:51

  本文选题：班公湖—怒江成矿带 + 东窝东铜矿床　； 参考：《现代地质》2016年06期

【摘要】：西藏改则县东窝东铜多金属矿床位于西藏多龙矿集区东部,是近年来班公湖—怒江成矿带上新发现的铜多金属矿。对区内花岗闪长斑岩和花岗斑岩进行了LA-ICP-MS锆石U-Pb年代学测试显示,成岩年龄为(121.0±1.2)Ma和(121.5±1.0)Ma,与多龙矿集区内成岩成矿年龄相近。研究区含矿斑岩显示了富集轻稀土和大离子亲石元素,亏损重稀土和高场强元素,中等Eu负异常,高铝、低镁、低钛,高Sr、低Y及Yb的岛弧岩浆岩特征,暗示矿区含矿岩浆与多龙矿集区含矿岩浆具备相同的岩浆源区。矿区含矿斑岩的锆饱和温度介于779.6~844.5℃,地球化学数据显示高Sr低Nd及低εNd(t)值特征;含矿斑岩εHf(t)为+3.4~+11.1,两阶段模式年龄T2DMC为467~963 Ma;表明其与多龙矿区含矿斑岩具备相似的Sr-Nd-Hf同位素特征,暗示了矿区含矿斑岩是班公湖—怒江特提斯洋洋壳向北俯冲消减背景下,由玄武质新生下地壳在较高温度条件下部分熔融形成的产物,指示班公湖—怒江洋盆于早白垩世晚期尚未关闭。野外地质调查发现,矿区发育典型斑岩铜矿蚀变分带;具备与多龙矿集区的岩石组成、矿化及蚀变、成岩成矿时代、构造环境和物质来源相类似的特征,且空间位置相近,暗示两者受控于统一的构造-岩浆成矿系统。综合分析认为,东窝东地区为多龙矿集区东延部分,具有寻找斑岩-浅成低温热液型铜(金)矿床隐伏矿体的良好潜力。
[Abstract]:The Dongwodong copper polymetallic deposit, located in the eastern part of the Dulong ore concentration area in Tibet, is a newly discovered copper polymetallic deposit in the Bangong Lake-Nujiang metallogenic belt in recent years. The LA-ICP-MS zircon U-Pb geochronology of granodiorite and granodiorite in this area shows that the diagenetic ages are 121.0 卤1.2)Ma and 121.5 卤1.0 Ma, which are similar to those in the Dulong ore accumulation area. The ore-bearing porphyry in the study area shows the characteristics of island arc magmatic rocks enriched in light rare earths and large ion lithophile elements, depleted heavy rare earths and high field strength elements, medium EU negative anomalies, high aluminum, low magnesium, low titanium, high Sr, low Y and Yb, It suggests that the ore bearing magma has the same magma source as the ore bearing magma in the Dulong ore concentration area. The zirconium saturation temperature of ore-bearing porphyry is between 779.6 鈩，

本文编号：1813839