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| 冈底斯泽当大型钨铜钼矿Re-Os年龄及陆缘走滑转换成矿作用 | |
| 引用本文： | 闫学义,黄树峰,杜安道.冈底斯泽当大型钨铜钼矿Re-Os年龄及陆缘走滑转换成矿作用[J].地质学报,2010,84(3). |
| 作者姓名： | 闫学义 黄树峰 杜安道 |
| 作者单位： | 1. 中国冶金地质总局矿产资源研究院,北京,100025 2. 中国冶金地质总局矿产资源研究院,北京,100025;中国冶金地质总局第二地质勘查院,福建甫田,351111 3. 国家地质实验测试中心,北京,100037 |
| 基金项目： | 《西藏冈底斯东段铜多金属资源评价与新方法技术研究》科研项目的成果 |
| 摘 要： | 在前人获取冈底斯成矿带泽当矿田冲木达铜金矿床条带状层矽卡岩型矿石浸染状辉钼矿Re-Os法等时线年龄40.3±5.6Ma的基础上,新获该矿田内另外两组Re-Os法等时线年龄:明则隐伏斑岩型钼矿床中辉钼矿Re-Os法等时线年龄为30.26±0.69Ma;努日层矽卡岩型钨铜钼矿床中与后期石英闪长玢岩体(E3δo)叠加改造成矿有关的斑点状辉钼矿Re-Os法等时线年龄为23.62±0.97Ma。以走滑型陆缘成矿新认识为出发点,总结了冈底斯成矿带陆缘走滑转换成矿作用的类型特征和时空分布:①斑岩型矿床和层矽卡岩矿床是区带内已知中大型铜多金属矿床的主要类型;②早期(68～38Ma)矿床受到"印-亚陆缘"会聚走滑阶段一、二级序左旋走滑转换构造控制,晚期(30～13Ma)矿床受到"印-亚陆缘"离散走滑阶段三、四级序左旋走滑转换构造控制;③斑岩型矿床的矿体形成受控于走滑推闭型转换断裂构造,层矽卡岩型矿床的矿体形成受控于走滑拉分型转换断裂构造;④区域走滑转换成矿构造应力场具逆时针旋转特征,显示68～13Ma间印度大陆相对亚洲大陆朝NEE作斜向对接作用,走滑主应力场被伸展主应力场替代时间以13～8Ma南北向碰撞裂谷的形成-活动为标志。提出"沿边找钼找钨、沿走滑转换构造带找铜金多金属矿,主攻斑岩-层矽卡岩复合型富-大矿"等今后区域找矿方向。 |
| 关 键 词： | 冈底斯 陆缘会聚走滑 转换成矿 泽当矿田 铜多金属矿 Re-Os年龄 Gangdisê |
Re-Os Ages of Large Tungsten, Copper and Molybdenum Deposit in the Zetang Orefield, Gangdisê and Marginal Strike-slip Transforming Metallogenesis |
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| YAN Xueyi,HUANG Shufeng,DU Andao.Re-Os Ages of Large Tungsten, Copper and Molybdenum Deposit in the Zetang Orefield, Gangdisê and Marginal Strike-slip Transforming Metallogenesis[J].Acta Geologica Sinica,2010,84(3). | |
| Authors: | YAN Xueyi HUANG Shufeng DU Andao |
| Abstract: | Based on the Re-Os isochron age (40.3±5.6Ma) of disseminated molybdenite from the Chongmuda skarn-type Cu-Au deposit in Gangdisê, Tibet, two sets of Re-Os isochron ages for the orefield were obtained. The molybdenite Re-Os isochron age of blind porphyry-type molybdenum deposit is 30.26±0.69Ma and spotted molybdenite Re-Os isochron age of Nuri layered skarn-type W-Cu -Mo deposit superimposed by later quartz diorite porphyry is 23.62±0.97Ma. Starting with the new understanding of strike-slip marginal metallogenesis, this paper summarizes the characters of marginal strik-slipping metallogenesis, and spatial-temporal distribution of porphyry deposits in the Gangdisê metallogenic belt. ① The porphyry-type deposits and stratiform skarn deposits are the primary types of the known medium-and-large-sized copper polymetallic deposits in the belt. ② Early (68～38Ma) deposits were controlled by the 1st-order and 2nd-order left-lateral strike-slip transforming structure in the strike-slip convergent stage of the "India-Asian continental margin", while late (30～13Ma) deposits by the 3rd-order and 4th-order left-lateral strike-slip transforming structure in the divergent strike-slip stage of the "India-Asian continental margin". ③ The formation of ore bodies in porphyry-type deposits is subject to strike-slip holding faults, while the formation of ore bodies of stratiform skarn deposit is subject to strike-slip dragging faults. ④ The stress field of regional strike-slip transform ore-forming structure is characterized by anti-clockwise rotation, which indicates that during 68～13Ma, the Indian Continent spliced obliquely towards northern northeast relative to the Asian Continent, and was replaced by the extensional-dominated stress field during the formation of South-North collisional rift at 13～8Ma. At last, this study outlines the orientation for ore exploration: molybdenum and tungsten deposits along the margin, and Cu-Au polymetallic along strike-slip transforming structure belt, with a main target at rich and large compound porphyry-type and stratabound skarn-type deposits. |
| Keywords: | marginal convergent strike-slip copper and molybdenum minerals Re-Os age Zetang Orefield Xizang(Tibet) |
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