摘要
铜坑-长坡锡石硫化物矿床是广西大厂锡多金属矿田中一个规模最大、特征最为典型的超大型锡矿床,矿体呈脉状、层状两种形式产出,其中的92号层状矿体是该矿床中规模最大的一个矿体。本文应用Rb-S等时线法获得92号矿体成矿年龄为93.4±7.9 Ma(1σ),这一年龄值不仅与矿田中部龙箱盖黑云母花岗岩的SHR IMP锆石U-Pb年龄93±1 Ma吻合,而且在测试误差范围内与前人所获得的龙头山100号矿体、铜坑-长坡91号矿体以及亢马矿床的成矿年龄基本一致,表明区内锡多金属成矿作用发生在燕山晚期。92号矿体成矿流体的87Sr/86Sr初始值为0.71351±0.00100,与龙箱盖黑云母花岗岩87Sr/86Sr的初始值0.7110接近。成矿年龄与成矿流体的87Sr/86Sr初始值均表明铜坑-长坡92号矿体的成矿作用与龙箱盖岩体具有一定的成生联系。
The Tongkeng-Changpo cassiterite-sulphide deposit, located in Guangxi autonomous region of south China, is a giant and typic deposit in the Dachang polymetallic tin ore field. It is composed of vein-type ore bodies at upper part and stratiform ones at bottom. The No. 92 stratiform orebody is the biggest one of the Tongkeng-Changpo deposit. The Rb-Sr isochron dating of fluid inclusions of quartz of No. 92 ore body is 93. 4 ± 1.3Ma（1σ）. This age is not only consistent with that of the Cretaceous Longxianggai biotite granite, but also coincident with that of the No. 100 ore body of the Longtoushan deposit, No. 91 ore body of the Tongkeng-Changpo ore body and the Kangma deposit. It indicates that they formed in late Yanshan movement. The initial 87^Sr/86^Sr of ore fluid of the No. 92 ore body is 0. 71352 ±0.00016, which is close to the value 0.7110 of the Longxianggai biotite granitite, and this also indicates that the mineralization of the No. 92 ore body probably has a genetic relationship with the Longxianggai magmatic body.
出处
《华南地质与矿产》
CAS
2006年第2期31-36,共6页
Geology and Mineral Resources of South China
基金
中国地质调查局地质调查项目(200310200072)
