广西花山花岗岩云英岩化分带与锡成矿过程的矿物学研究

云英岩脉型锡矿是广西花山花岗岩的主要矿化类型之一。花山花岗岩是氧化型花岗岩，岩体中的锡主要以Sn4+ 的形式，赋存于黑云母、角闪石、榍石、金红石、钛铁矿和锡石等含锡矿物中。通过矿物学研究发现，云英岩化过程是：经充 分分异和演化形成的残余岩浆流体与中细粒黑云母花岗岩相互作用。首先，黑云母等原生含锡矿物中的锡在岩浆流体的作 用下被淋滤出，进入流体或次生矿物相，如金红石、白云母等，发生初步富集；其次，在蚀变后期，成矿流体使早先沉淀 的含锡矿物发生重溶，锡溶解进入成矿流体再次富集。锡在流体中与丰富的F- ，Cl - 等络阴离子结合成稳定的配合物运移， 随着云英岩化加深，流体的pH值升高、温度降低、络阴离子浓度降低，流体中配合物的稳定性降低发生沉淀形成锡矿化

Mineralogical Study on Greisenization Zoning and Tin Mineralization in Huashan Granite, Guangxi, South China

Greisen-vein type tin deposits are the most important mineralization type in Huashan granite, Guangxi, South China: The Huashan granite is an oxidized-type granite. In this granite body the element tin predominantly exists as Sn4+ in primary tinbearing minerals, such as biotite, amphibole, titanite, rutile, ilmenite and cassiterite. Based on the comprehensive mineralogical study, we recognize that greisenization developed through interaction of the medium-fine-grained biotite granite with a residual magmati...