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| 青海同仁县江里沟斑岩-矽卡岩型铜钨钼矿床辉钼矿Re-Os同位素年龄及其成矿意义 | |
| 引用本文： | 张涛,张德会,杨兵,张辉,喻晓.青海同仁县江里沟斑岩-矽卡岩型铜钨钼矿床辉钼矿Re-Os同位素年龄及其成矿意义[J].地质学报,2015,89(2):355-364. |
| 作者姓名： | 张涛 张德会 杨兵 张辉 喻晓 |
| 作者单位： | 1. 中国地质大学(北京)地球科学与资源学院,北京,100083;青海省有色地质矿产勘查局七队,西宁,810007 2. 中国地质大学(北京)地球科学与资源学院,北京,100083 3. 西部矿业股份有限公司,西宁,810001 |
| 基金项目： | 青藏专项项目，西部矿业基金项目联合资助的成果 |
| 摘 要： | 西秦岭同德—泽库多金属成矿带是青海省重要的矿产集中区之一,位于西秦岭北缘斑岩-矽卡岩型铜、钼、金成矿带的最西端。江里沟矿床是该区的重要组成部分,为一个典型的斑岩型-矽卡岩型铜钨钼矿床。本文利用Re-Os同位素定年方法对江里沟铜钨钼矿床进行了成矿时代测定,获得了5件样品辉钼矿的Re-Os同位素模式年龄范围为219.5±3.1~222.2±4.0Ma,等时线年龄为224.3±7.3Ma。矿区二长花岗岩SHRIMP锆石UPb年龄测定结果表明岩石存在两个期次结晶年龄232±4Ma和214±4Ma,矿区花岗岩可能是两个期次岩浆活动的产物。根据斑岩型矿床矿化晚于成矿母岩的特征,认为江里沟矿床成矿时代属晚三叠世,与矿区232Ma期次的岩浆侵入活动关系密切,成矿晚于成岩约8Ma,成矿与成岩时代基本一致,是西秦岭印支期构造-岩浆活动的产物。本次研究可以大致确定岗察复式岩体周边矿床成矿时限为243.8~214Ma,与区域西秦岭—东昆仑三叠纪构造岩浆作用和成矿时代一致,构成西秦岭北缘斑岩-矽卡岩型铜-钼-金成矿系统的一部分。 |
| 关 键 词： | 斑岩-矽卡岩型矿床 辉钼矿Re-Os年龄 斑岩-矽卡岩 江里沟铜钨矿 青海同仁 |
| 收稿时间： | 2014/5/28 0:00:00 |
| 修稿时间： | 2014/10/15 0:00:00 |
Re-Os Dating of Molybdenite from the Jiangligou Porphyry-Skarn Cu-W-Mo Deposit in Tongren Qinghai Province andIts Metallogenic Significance |
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| ZHANG Tao,ZHANG Dehui,YANG Bing,ZHANG Hui and YU Xiao.Re-Os Dating of Molybdenite from the Jiangligou Porphyry-Skarn Cu-W-Mo Deposit in Tongren Qinghai Province andIts Metallogenic Significance[J].Acta Geologica Sinica,2015,89(2):355-364. | |
| Authors: | ZHANG Tao ZHANG Dehui YANG Bing ZHANG Hui and YU Xiao |
| Institution: | ZHANG Tao;ZHANG Dehui;YANG Bing;ZHANG Hui;YU Xiao;School of Earth Science and Mineral Resources,China University of Geosciences;No.7 Team of Qinghai Geological Exploration Bureau for Nonferrous Metals;Western Mining Group Company Limited; |
| Abstract: | The Tongde-Zeku polymetallic metallogenic belt in West Qinling is one of the most important mineral concentrated areas in Qinghai Province found at the westernmost end of the porphyry-skarn type Cu-Mo-Au metallogenic belt on the northern margin of West Qinling. Jiangligou deposit, which forms an important part of this area, is a typical porphyry-skarn type Cu-W-Mo deposit. In this paper, the ore-forming age of Jiangligou Cu-W-Mo deposit is measured using Re-Os isotopic dating before yielding the Re-Os isotopic pattern age of 219.5±3.1~222.2±4.0Ma and isochronic age of 224.3±7.3Ma for the five sample molybdenite ores. SHRIMP zircon U-Pb dating of the adamellite in the ore district suggests two stages of crystallization, 232±4Ma and 214±4Ma, implying that the granite in the area might be the product of two magmatism events. As porphyry type deposits are mineralized later than the ore-forming parent rock, we date the ore-forming of Jiangligou deposit back to Late Triassic. Its mineralization should have been closely associated the magmatic intrusion in the area at 232Ma, approximately 8Ma later than the rock-forming. The mineralization took place roughly at the same time as rock-forming. It is the product of the Indosinian tectono-magmatic activity in West Qinling. Our study has confined the approximate ore-forming time of deposits surrounding the Gangcha complex to 243.8~214Ma, which concurs with the Triassic tectono-magmatic process and ore-forming time of the West Qinling-East Kunlun region of the area, proving that the deposit is part of the porphyry-skarn type Cu-Mo-Au metellogenic system on the northern margin of West Qinling. |
| Keywords: | Porphyry-skarn type deposit molybdenite Re-Os isotopic dating Jiangligou copper-tungsten-molybdenum deposit Tongren County Qinghai |
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