云南格咱岛弧带休瓦促Mo-W-Cu矿床两期岩浆作用的锆石U-Pb年龄、Hf同位素组成及构造意义

发布时间：2018-03-22 08:32

本文选题：锆石U-Pb年龄　切入点：Hf同位素组成　出处：《地质学报》2017年04期 　论文类型：期刊论文

【摘要】：锆石LA-ICP-MS U-Pb定年结果显示,休瓦促Mo-W-Cu矿床含矿花岗闪长岩的形成年龄为202±3.5Ma,形成于甘孜-理塘洋壳向西俯冲时期;含矿二长花岗岩的形成年龄为83.3±1.7Ma,形成于燕山晚期造山后伸展环境。Hf同位素原位分析结果显示,花岗闪长岩中锆石的ε_(Hf)(t)值为-2.87~4.12(平均为0.09),T_(MD1)年龄541~828Ma,T_(DM2)年龄为719~1109Ma,表明岩体形成的物质来源除壳源物质之外,也有幔源物质的混入;二长花岗岩中锆石的ε_(Hf)(t)值为-7.96~-2.75(平均为-5.54),T_(MD1)年龄为820~1019Ma,T_(DM2)年龄为1102~1391Ma,ε_(Hf)(t)0,表明岩石是由古老地壳物质的部分熔融形成的产物。休瓦促两期含矿岩体的锆石U-Pb定年与Hf同位素原位分析显示,区内存在晚三叠世和晚白垩世两期构造-岩浆-成矿作用。晚三叠世花岗闪长岩岩浆侵入及Cu多金属成矿作用与洋壳俯冲造山有关;而晚白垩世二长花岗岩岩浆侵入及Mo多金属成矿作用主要形成于陆-陆碰撞造山的构造背景。研究表明,从晚三叠世洋壳俯冲造山至晚白垩世造山后伸展作用过程中都存在构造-岩浆-成矿作用的发生,且在晚三叠世构造-岩浆活动的基础上叠加了晚白垩世的成岩成矿作用,这为区内复合叠加成矿作用的研究提供了例证。
[Abstract]:The results of zircon LA-ICP-MS U-Pb dating show that the age of the granodiorite in the Mo-W-Cu deposit is 202 卤3.5 Ma, which was formed during the westward subduction of the Ganzi-Litang oceanic crust. The age of formation is 83.3 卤1.7 Ma.It was formed in the post-orogenic extensional environment of late Yanshanian. The 蔚 _ S _ S _ H _ F _ (t) value of zircon from granodiorite is -2.87 ~ (4.12) (average is 0.09 ~ (?) T ~ (-1) D _ (1)) age is 541 ~ 828 Ma ~ (-1) T ~ (10 ~ (2)), which indicates that the material source of the formation of the granodiorite is 719 ~ 1109 Ma, which indicates that the material source of the rock formation is not only the crust source material, but also the mantle source material. The zircon 蔚 ~ (-1) value of zircon in the monzogranite is -7.96 ~ 2.75 (an average of -5.54 ~ (-5.54) T ~ (+) D _ (1)) age is 820 ~ 1019 Ma ~ (-1) D _ (2), 蔚 ~ (-1) ~ (-1) ~ (-1), indicating that the rocks were formed from the partial melting of the ancient crustal material, and the zircon U-Pb dating and HF isotope in situ analysis of the ore-bearing ore-bearing bodies in the Huwa-promoting period show that the zircon dating and HF isotopic analysis show that the zircon dating and HF isotopic dating of the ore-bearing rocks in the Xiwa stage are related to the formation of zircon dating and HF isotopic analysis. The late Triassic and late Cretaceous tectonic-magmatic mineralization occurred in the area. The late Triassic granodiorite magma intrusion and Cu polymetallic mineralization are related to oceanic crust subduction orogeny. The late Cretaceous magmatic intrusion and Mo polymetallic mineralization mainly occurred in the tectonic setting of continental-continental collision orogeny. From late Triassic ocean crust subduction orogeny to late Cretaceous post-orogenic extension, tectonic-magmatic mineralization occurred, and the late Cretaceous diagenesis was superimposed on the basis of late Triassic tectonic-magmatic activity. This provides an example for the study of complex superposition mineralization in the region.
【作者单位】：昆明理工大学;中国地质调查局成都地质调查中心;
【基金】：云南省科技领军人才培养计划项目(编号:2013HA001) 云南省教育厅基金项目(编号:2015Y066) 国家自然科学基金项目(编号:41502076) 中国地质调查局项目(编号:12120114013701)资助的成果
【分类号】：P597.3;P618.2

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