新疆西天山加曼特金矿床赋矿围岩年代学、地球化学及地质意义

发布时间：2018-02-10 06:19

本文关键词： 岩屑晶屑凝灰岩花岗斑岩锆石U-Pb定年地球化学加曼特金矿床新疆　出处：《现代地质》2017年02期 　论文类型：期刊论文

【摘要】：加曼特金矿床是西天山博罗科努多金属成矿带中的一个浅成低温热液金矿床。矿床赋存于晚古生代大哈拉军山组岩屑晶屑凝灰岩和花岗斑岩中。LA-ICP-MS锆石U-Pb同位素定年结果显示岩屑晶屑凝灰岩、花岗斑岩的成岩时代分别为(365.9±3.0)Ma和(362.3±4.3)Ma,结合上覆阿恰勒河组地层中维宪阶生物化石的时代,加曼特金矿的成矿时代被约束在362~331 Ma之间。矿区岩石地球化学分析结果表明:二者均为高钾钙碱性系列岩石,富集轻稀土、Th和大离子亲石元素(Rb、K),亏损Ba、Sr、高场强元素(Nb、Ta、Ti、P)和重稀土元素,具有同源性和岛弧岩浆岩的地球化学亲缘性。岩石形成于古准噶尔洋向伊犁—中天山板块俯冲的活动大陆边缘弧环境,主要是下地壳基性岩石部分熔融的产物,混合了少量洋底沉积物熔体交代地幔楔形成的幔源岩浆。
[Abstract]:The Gamante gold deposit is an epithermal hydrothermal gold deposit in the Borokonu polymetallic metallogenic belt of the West Tianshan Mountains. The deposit occurred in the late Paleozoic Dahalajunshan formation lithic grain chrysotile tuff and granitic porphyry. LA-ICP-MS zircon U-Pb isotopic determination. The results show that the clastic grain tuff, The diagenetic ages of granitic porphyry are 365.9 卤3.0 Ma and 362.3 卤4.3 Ma, respectively. The metallogenic age of the Gamante gold deposit is confined to 362or 331Ma. The geochemical analysis of rocks in the ore area shows that both of them are of high-potassium calc-alkaline series rocks. It is rich in light rare earth elements (Th) and large ion lithophile elements (RbHK), depleted BaFO Sr, high field strength elements (NbSe TahttiPe) and heavy rare earth elements (HREE), and heavy rare earth elements. The rocks were formed in the active continental margin arc environment of the ancient Junggar Ocean subducting to the Yili-Middle Tianshan plate, and mainly resulted from the partial melting of the basement rocks in the lower crust. A small amount of ocean floor sediments melt metasomatic mantle wedge formation of mantle magma.
【作者单位】：中国地质大学(北京)地球科学与资源学院;中国地质大学地质过程与矿产资源国家重点实验室;新疆有色地质勘查局七0三队;
【基金】：国家自然科学基金项目(41572062,U1303292) 中央返还两权价款资金综合研究项目(Y15-1-LQ04) 国家科技支撑计划项目(2011BAB06B02-02)
【分类号】：P618.51

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