| 广东省大宝山矿床两阶段岩浆岩先铜后钨成矿模式——矽卡岩中石榴子石U-Pb年龄的约束 |
| 点此下载全文 |
| 引用本文：李剑,赵如意,李凯旋,王登红,蒋金昌,秦锦华,张熊,赵晨辉,李挺杰,王成辉,刘武生.2026.广东省大宝山矿床两阶段岩浆岩先铜后钨成矿模式——矽卡岩中石榴子石U-Pb年龄的约束[J].地球学报,47(4):820-836. |
| DOI：10.3975/cagsb.2026.050711 |
| 摘要点击次数: 145 |
| 全文下载次数: 17 |
|
| 基金项目:本文由科技部重点研发计划项目(编号: 2021YFC2901902)、广东省大宝山九曲岭斑岩铜矿找矿钻探验证项目钻探相关地质技术服务 项目(编号: H202400182)、大宝山矿区北部斑岩型铜矿成因机制与控矿因素研究(编号: H202300181)和中国地质调查局中国矿产地质与成矿规律综合集成和服务(矿产地质志)项目(编号: DD20160346)联合资助。 |
|
| 中文摘要:广东省大宝山是华南地区重要的铜多金属矿床, 矿区发育的岩浆岩主要为英安斑岩和花岗闪长斑岩, 主要矿化类型为Cu多金属矿化和W、Mo矿化, 但成岩成矿时代及成因机制长期存在争议。文章以大宝山矿区矽卡岩中石榴子石为研究对象, 在详细的微观研究基础上, 对三阶段石榴子石进行LA-ICP-MS U-Pb定年, 获得的石榴子石年龄分别为: (175.6±6.9) Ma、(163.0±7) Ma和(139.9±1.9) Ma, 揭示矿区在燕山早期经历了三次强烈的构造-岩浆热液活动。第一阶段石榴子石年龄((175.6±6.9) Ma)与英安斑岩(~175 Ma)形成时代一致, 表明该阶段矽卡岩及其中产出的铜多金属矿是燕山早期英安斑岩侵位的产物。第二阶段石榴子石年龄((163.0±7) Ma)与花岗闪长斑岩年龄(166~161 Ma)一致, 与W、Mo成矿作用有关, 其成矿时代晚于Cu多金属矿化。第三阶段石榴子石年龄((139.9±1.9) Ma), 该阶段矽卡岩可能与辉绿岩脉侵位及区域伸展背景有关。综合研究了大宝山矿区成矿条件和成岩成矿作用, 建立了“双推双侵双成”成矿模式: 先是燕山早期英安斑岩沿北北西向逆冲推覆构造侵位形成铜铅锌矿体; 接着花岗闪长斑岩沿近东西向逆冲推覆构造侵位带来钼钨矿化; 后来, 可能是燕山晚期陆内伸展环境下侵位的辉绿岩脉及深部流体的共同作用形成了第三阶段石榴子石。最后, 表生氧化富集形成了褐铁矿矿体及其下部的高品位次生铜矿。该模型揭示了大宝山多阶段复合成矿过程, 深化了对大宝山燕山期构造-岩浆-成矿系统的认识。 |
| 中文关键词:大宝山 石榴子石 LA-ICP-MS U-Pb定年 矽卡岩 成矿时代 燕山早期 构造-岩浆-成矿系统 |
| |
| Early Copper and Late Tungsten Mineralization Model Distinct Related to Two-stage Magmatism of the Dabaoshan Deposit in Guangdong Province: Constraints from U-Pb Age of Garnet in Skarn |
|
|
| Abstract:Dabaoshan in Guangdong Province is an important copper polymetallic deposit in southern China. The magmatic rocks developed in the mining area are mainly dacite porphyry and granodiorite porphyry, and the main mineralization types are Cu polymetallic mineralization and W, Mo mineralization. However, the diagenetic mineralization age and genesis mechanism have long been controversial. The article takes garnet in the skarn of the Dabaoshan mining area as the research object. Based on detailed microscopic studies, LA-ICP-MS U-Pb dating was performed on three stages of garnet, and the ages obtained were (175.6±6.9) Ma, (163.0±7) Ma, and (139.9±1.9) Ma, revealing that the mining area experienced three strong tectonic magmatic hydrothermal activities in the early Yanshan period. The age of garnet in the first stage ((175.6±6.9) Ma) is consistent with the formation age of the dacite porphyry (~175 Ma), indicating that the skarn and the copper polymetallic deposits produced in it are products of the early Yanshan dacite porphyry intrusion. The age of garnet in the second stage ((163.0±7) Ma) is consistent with the age of granodiorite porphyry (166–161 Ma), which is related to the mineralization of W and Mo, and its mineralization age is later than that of Cu polymetallic mineralization. The age of garnet in the third stage ((139.9±1.9) Ma) may be related to the intrusion of diabase veins and regional extensional background in the skarn. A comprehensive study was conducted on the mineralization conditions and diagenetic processes in the Dabaoshan mining area, and a “double push, double invasion, and double formation” mineralization model was established. Firstly, the early Yanshanian dacite porphyry was emplaced along the north northwest trending thrust structure to form copper lead zinc ore bodies; Subsequently, granite diorite porphyry intruded along the nearly east-west thrust structure, resulting in molybdenum tungsten mineralization; Later, it is possible that the third stage of garnet was formed by the combined action of the intrusion of diabase veins and deep fluids in the late Yanshanian intracontinental extensional environment. Finally, surface oxidation enrichment formed the limonite ore body and its lower high-grade secondary copper deposits. This model reveals the multi-stage composite mineralization process of Dabaoshan and deepens the understanding of the Yanshanian tectonic magmatic mineralization system in Dabaoshan. |
| keywords:Dabaoshan garnet LA-ICP-MS U-Pb dating skarn mineralization age early Yanshan period tectonic-magmatic-mineralization system |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|
