| 湖南芙蓉锡矿床锡矿石和有关花岗岩的40Ar-39Ar年龄及其地球动力学意义 |
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| 引用本文：.2004.40Ar-39Ar Dating of Tin Ores and Related Granite in Furong Tin O refield, Hunan Province, and Its Geodynamic Significance[J].Mineral Deposits,23(2):164~175 |
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| 基金项目:国家基础研究规划项目(编号：G19990432116和G1999043211) |
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| 中文摘要:在研究和介绍湖南芙蓉锡矿矿床地质特征的基础上 ，对云英岩型锡矿石中的白云母和与成矿有关的骑田岭角闪黑云花岗岩中的黑云母进行了40Ar-39Ar年龄测定，获得角闪黑云花岗岩的坪年龄为(157.5±0.3) Ma；三门云 英岩锡矿石的坪年龄为(156.1±0.4) Ma；淘洗窝云英岩锡矿石的坪年龄(160.1±0.9) Ma。 这3组测年数据很一致，不仅精确地反应出成岩成矿的时间限制，而且表明了花岗岩成岩与 锡矿成矿的密切关系。此外，三组数据坪年龄一致显示出，在成岩成矿之后矿体未受到后期 热事件的扰动。芙蓉锡矿床是湘南大型钨锡多金属矿集区的组成部分，也是华南地区中生代 钨锡成矿两大高峰期之一的160～135 Ma期间形成的代表性矿床，可能为中国东部地球动力 学体制调整时晚期岩石圈减薄过程中的产物。 |
| 中文关键词:地球化学 Ar-Ar年龄 云母 锡矿床 芙蓉 湖南省 |
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| 40Ar-39Ar Dating of Tin Ores and Related Granite in Furong Tin O refield, Hunan Province, and Its Geodynamic Significance |
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| Abstract:Furong, a large tin orefield newly discovered in southern Hunan Province, is one of the most important W_Sn_Bi mineralization areas in the world. At present, th e controlled reserves amount to about 600,000 tons of tin metal with an average grade of 0.8%. Further exploration is ongoing, and more than 40 ore veins have b een explored, which are located in the southern portion of the Qitianling Yansha nian amphibole_biotite granite pluton and hosted in Carboniferous and Permian ca rbonate rocks. The veins generally occur in swarms, forming Bailashui_Anyuan, He ishanli_Maziping and Shanmenkou_Goutouling tin zones. Previous workers identifie d 7 to 8 types of mineralization in the ore district, but the main orebodies of commercial value seem to be of skarn, chlorite and greisen types. The first area is characterized by skarnization and chloritization, while the last two areas m ainly by greisenization.40Ar/39Ar dating was performed on muscovite from greisen_type ti n ore and biotite from related amphibole_biotite granite, which yielded three se ts of age data, i.e., a plateau age of (157.5±0.3) Ma for amphibole_biotite gra nite, a plateau age of (156.1±0.4) Ma for the Sanmen greisen_type tin ore and a plateau age of (160.1±0.9) Ma for the Taoxiwo greisen_type tin ore. Coincident well with each other, these three sets of age data not only accurately reflect the timing of rock and ore formation but also indicate the close relation betwee n granite and tin ore. In addition, the plateau ages of the three sets suggest t hat no subsequent thermal perturbation occurred after the formation of granite a nd tin deposits. As part of the southern Hunan polymetallic tungsten_tin provinc e, the Furong tin orefield was formed in a pulsation of 160～135 Ma, an importan t time for W_Sn_Mo_Bi_Be_Cu mineralization in South China, which is supposed to have been caused by lithospheric thinning processes. |
| keywords:geochemistry, Ar_Ar age, mica, tin deposit, Furong, Hunan Province |
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