摘要
通过对安徽祁门廖家地区矿区进行1∶1万地质调查工作与1∶1000地质剖面测量工作,认识和总结了廖家地区出露的地层岩性组合及其沉积特征,确定了矿区的基本构造格架、主要控矿构造及其演化历史。在此基础上,运用构造地球化学方法进行了找矿研究。因子分析及对应分析表明,上溪群及石英脉均富集铁族元素组合Cr、Ni、Co、V、Ti,反映其组成上具有一定的亲源性;石英脉中Au、As元素组合相关性强,As可能作为成矿介质参与金的成矿作用。利用分形理论,对不同地质体金含量的分形结构特征进行了研究。因子得分等值线图表明,F1因子(Cr、Ni、V、Ti、Co)得分高值区与岩浆岩分布范围一致。成矿元素因子得分高值区明显受北东向与近东西向构造控制。显然东西向断裂是下一步金矿找矿的重点区段。本区的金矿类型为受断裂控制的含金石英脉型与层间破碎带型。上溪群可能是本区金矿的成矿物质来源,而岩浆岩主要提供热源,构造既作为成矿作用,也提供了有利的成矿环境和聚矿空间。
According to 1∶10000 geological survey and 1∶1000 geological profile survey in the study area,the authors summed up the lithologic combination and sedimentary characteristics,the basic structure framework,the main ore-control structures and the evolution history.On such a basis and by using the tectono-geochemical prospecting method,the authors have reached the following conclusions: The NE-and nearly EW-trending fractural structures formed the main structural framework in this area.From early to late,the tectonic evolution of this area can be divided into four stages,namely the NW-SE compression(pre-metallogenic),the S-N compression(pre-metallogenic),the NW-SE extension(metallogenic) and NW-SE extension(metallogenic).Factor analysis and correspondence analysis show that both Shangxi Group and quartz veins are rich in iron group elements such as Cr,Ni,Co,V and Ti,suggesting that there exists a definite affinity in their composition.Au is strongly correlated to As in quartz veins,and As is likely to act as an ore-forming medium in gold mineralization.The utilization of the fractal method to study the fractal texture of gold content in different geological bodies has been studied in this paper.The fractal textures of magmatic rocks and quartz veins are simple.Their fractal dimension values are of three sections,and those of Shangxi Group are of five sections.Factor score contour diagram indicates that the high score sections of F1 factor(Cr,Ni,V,Ti,Co)are consistent with the distribution areas of magmatic rocks.The high score sections of the metallogenic elements are controlled by NE-and nearly EW-trending geological structures.It is obvious that the WE-trending fracture is the key section for further gold ore-prospecting work.Gold deposits in this area are mainly of the types of gold-bearing quartz veins and interstratified fracture zone.Shangxi Group was probably the source of metallogenic substance for gold mineralization in this area,magma mainly offered heat,and geological structures acted as mechanism of metallogenic action and favorable metallogenic environment as well as ore concentration space.
引文
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