| 西藏雄村矿集区侏罗纪斑岩磷灰石矿物化学特征对新特提斯洋俯冲成矿作用的指示 |
| |
| 关键词:Xiongcun ore concentration area apatite oxidized/reduced porphyry copper gold deposit Jurassic porphyry Neo-Tethys Ocean, Gangdise metallogenic belt |
| 基金项目:国家自然科学基金项目(编号: 41502079);中国地质调查局地质调查项目(编号: 12120114068401) |
|
| 摘要点击次数: 3399 |
| 全文下载次数: 1684 |
| 摘要: |
| Geochemistry of Apatite from Jurassic Porphyry in the Xiongcun Ore Concentration Area, Southern Gangdise Porphyry Copper Belt:Implications for Neo-Tethys Mineralization |
| The Xiongcun ore concentration area is located on the southern margin of the Gangdise metallogenic belt, Tibet. The mineralization in the Xiongcun ore concentration area where a large reduction porphyry copper gold deposit (No. I orebody) and a large oxidized porphyry copper gold deposit (No. II orebody) were explored and evaluated related to the subduction of the Neo-Tethys. In order to find out the difference of ore-forming characteristics of No. Iand No. II orebody and the difference between fertile porphyry and barren porphyry, the authors selected apatite from No. I and No. II fertile porphyries and barren porphyry as the research object. Through the selection of apatite from three porphyries, cathodoluminescence (CL) and electron microprobe analysis (EMPA) were conducted, and the authors found that the content of Cl in apatite is controlled by the composition of coexisting silicate melt, and No.Ⅰ and No.Ⅱ fertile porphyries have higher Cl/F than barren porphyry (0.76, 0.26, 0.07, respectively), which indicates that high Cl content played an important role in accelerating the dissolution and migration of Cu and Au. The high Cl and low S in apatite of fertile porphyries indicate that the Cu and Au probably migrated mainly in the form of Cl complexes such as [CuCl2]–, [CuCl]0, and [AuCl2]–. The oxygen fugacity of fertile porphyries is lower than that of barren porphyry, and the low oxygen fugacity of fertile porphyries may indicate that saturation of the magma with sulfide might have occurred in the mineralization process. Compared with apatite of barren porphyry, the apatite of fertile porphyries has higher content of Mn, Ca, Cl and lower content of Si, S, F, and thus apatite can be used as an indicator mineral for mineral exploration related to the subduction of the Neo-Tethys on the southern margin of the Gangdise metallogenic belt. |
| XIE Fu-wei,LANG Xing-hai,TANG Ju-xing.2017.Geochemistry of Apatite from Jurassic Porphyry in the Xiongcun Ore Concentration Area, Southern Gangdise Porphyry Copper Belt:Implications for Neo-Tethys Mineralization[J].Acta Geoscientica Sinica,38(5):813-828. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|