四川省石棉县大水沟碲矿床地质,矿物学和地球化学 |
|
关键词:tellurium deposit geology mineralogy geochemistry Shimian Sichuan |
基金项目: |
|
摘要点击次数: 4664 |
全文下载次数: 4144 |
摘要: |
Geology, Mineralogy, and Geochemistry of the Dashuigou Tellurium Deposit in Shimian County, Sichuan |
To date Dashuigou tellurium deposit, located on the west margin of Yangtze platform, is, thesole example of tellurium- dominated deposit in the world. The host rock for the mineralization is alayer of Triassic metamafic rock 30m to 50m thick. Thirteen ore veins, which strike 0°to 10° anddip 270° to 280° of angles of 60° to 70°,have been discovered in the deposit. These veins are general-ly about one hundred to several hundred meters long, dosens of centimenters thick, and severaldozen to more than one hundred meters deep; Tellurium mineralizations in the deposit can be divid-ed into three stages,i.e, pyrrhotite-pyrite stage, tetradymite stage, and pyrite-chalcopyrite(nativegold)stage, The tetradymite stage is the most important of them in reserve of tellurium, and it com-pries several species of tellurium-bearing minerals, such as, tetradymite , tsumoite, tellurbisrnuth,jodeite, stuetzite,native tellurium, wehrlite, and calaverrte. The tellurium grades of the ores gen-erally range from 0.2%to 5%,and are 15%一25% for the rich ores; Gangue minerals in the oresare dolomite biotite,muscovite,albite, quartz, chlortz and calcite, Wall rock alteralions around theore veins intensively develop and usually exhibit zoningS in space. The alteration zones around thepyrrhotite- pyrite ore veins include coarse-grained biotite zone, fine- grained quartz-albite- biotitezone, quartz-biotite-actinolite zone to chlorite-amphibole zone. The alteration zones around the te-tradymite ore veins are fine-grained hematite-calcite-muscovite zone, quartz-calcite-chlorite-action-lite zone,and chlorite-amphibele zone. K, Na and Ca decrease, and Fe and Mg increas from the oreveins outward. A K-Ar agr of 149. 86±2. 72 Ma has been measured from seperated muscovite inthe ore veins. Genetic mineralogy and geochemistry indicate that the tellurium mineralizations in theDashuigou deposit is possibly related to the buried alkaline granite or syenite-leucitite intrusions 14O-80 Ma in age, which occur in surrounding areas of the deposit. Sulfur fugacity(fs_2)and telluriumfugacity(fTe_2)are 10 ̄(-16.7) and 10 ̄(-15)一10 ̄(-14_) respoctively. during the pyrrhotite-pyrite stage, and10 ̄(-14)一10 ̄(-11) and 10 ̄(11.2)一10 ̄(-10.5) for the tetradymite stage. |
MAO Jing-wen,CHEN Yu-chuan,ZHOU Jian-xiong,YANG Bai-chuan.1995.Geology, Mineralogy, and Geochemistry of the Dashuigou Tellurium Deposit in Shimian County, Sichuan[J].Acta Geoscientica Sinica,16(3):276-290. |
查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|