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| 西藏冈底斯成矿带甲马和知不拉铜多金属矿床的Re-Os同位素年龄及其意义 | |
| 引用本文： | 李光明,芮宗瑶,王高明,林方成,刘 波,佘宏全,丰成友,屈文俊.西藏冈底斯成矿带甲马和知不拉铜多金属矿床的Re-Os同位素年龄及其意义[J].矿床地质,2005,24(5):481-489. |
| 作者姓名： | 李光明 芮宗瑶 王高明 林方成 刘 波 佘宏全 丰成友 屈文俊 |
| 作者单位： | 1. 中国地质科学院矿产资源研究所,北京,100037;中国地质调查局成都地质矿产研究所,四川,成都,610082 2. 中国地质科学院矿产资源研究所,北京,100037 3. 中国地质调查局成都地质矿产研究所,四川,成都,610082 4. 中国地质科学院国家地质实验测试中心,北京,100037 |
| 基金项目： | 本文得到国家自然科学基金（40272047）、国家重点基础发展计划（2002CB412609）和中国地质调查局地质大调查项目（200310200008）的联合资助 |
| 摘 要： | 文章首次对冈底斯成矿带的甲马和知不拉铜_铅_锌矿床的辉钼矿进行了Re_Os同位素定年。甲马矿区辉钼矿的模式年龄介于15.4～15.5Ma之间,7件样品得到187Re_187Os等时线年龄为(15.18±0.98)Ma。知不拉矿区辉钼矿样品的模式年龄介于16.88～17.06Ma之间,5件样品得到187Re_187Os等时线年龄为(16.90±0.64)Ma。获得的Re_Os年龄与冈底斯成矿带驱龙、拉抗俄和冲江、厅宫等斑岩铜矿床的成矿年龄一致,明显晚于侏罗纪拉萨弧间盆地的发育时限。据此作者认为甲马和知不拉等铜_铅_锌矿床不属于喷流型矿床,而是冈底斯成矿带斑岩_矽卡岩成矿系统的组成部分,是岩浆_热液流体系统在不同的深度条件下与富钙围岩交代成矿的产物。 |
| 关 键 词： | 地球化学 铜多金属矿床 Re-Os年龄 斑岩-矽卡岩成矿系统 甲马 知不拉 西藏 |
| 文章编号： | 0258-7106（2005）05-0481-09 |
| 收稿时间： | 2004-11-19 |
| 修稿时间： | 2004-11-192005-06-02 |
Molybdenite Re-Os dating of Jiama and Zhibula polymetallic copper deposits in Gangdese metallogenic belt of Tibet and its significance |
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| LI Guang-ming,RUI Zong-yao,WANG Gao-ming,LIN Fang-cheng,LIU Bo,SHE Hong-quan,FENG Cheng-you,QU Wen-jun.Molybdenite Re-Os dating of Jiama and Zhibula polymetallic copper deposits in Gangdese metallogenic belt of Tibet and its significance[J].Mineral Deposits,2005,24(5):481-489. | |
| Authors: | LI Guang-ming RUI Zong-yao WANG Gao-ming LIN Fang-cheng LIU Bo SHE Hong-quan FENG Cheng-you QU Wen-jun |
| Institution: | LI Guang-ming 1,2,RUI Zong-yao1,WANG Gao-ming2,LIN Fang-cheng2,LIU Bo2,SHE Hong-quan1,FENG Cheng-you1 and QU Wen-jun3 |
| Abstract: | The origin of the Jiama and the Zhibula polymetallic copper deposits in the Gangdese metallogenic belt, southern Tibet, is a problem of long controversy. This paper gives for the first time the highly precise Re_Os age of molybdenite from these two polymetallic copper deposits. The Re_Os model ages of 7 molybdenite samples from the Jiama deposit vary from (15.4±0.2) Ma to (15.5±0.2) Ma, yielding an isochron age of (15.18±0.98) Ma. The Re_Os model ages of 5 molybdenite samples from the Zhibula deposit vary from (16.88±0.28) Ma to (17.06±0.27) Ma, yielding an isochron age of (16.90±0.64) Ma. These ages are much younger than the ages of the Gangdese inter_arc sedimentary basin development and the ages of collisional granitic intrusive rocks in the Gangdese belt, but are obviously consistent with the ore_forming ages of the near_by porphyry copper deposits, such as Qulong, Lakang'e, Chongjiang and Tingguan in the Gangdese metallogenic belt. These Re_Os ages suggest that the Jiama and the Zhibula polymetallic copper deposits were formed in the same porphyry_skarn ore_forming system in a post_collisional extensional tectonic setting of Miocene epoch. The porphyry copper deposits and the skarn type polymetallic copper deposits in the Gangdese metallogenic belt were formed by different ore_forming processes of the magmatic_hydrothermal system in different wall rocks. |
| Keywords: | geochemistry copper polymetallic deposit Re-Os age porphyry-skarn ore-forming system Jiama Zhibula Tibet |
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