云南个旧陡岩勘查区Sn多金属矿化信息提取与评价

个旧矿区被南北向个旧断裂分为东、西2个矿区。东区是已知矿床的集中区,随着东区"危机矿山"问题的日益凸显,西区的地质研究工作和资源潜力评价已成为矿山深部和外围找矿的热点。西区陡岩地区具有良好的成矿地质条件,是近年来个旧西区地质找矿工作的重点。采用因子分析(FA)-多重分形法(S-A)对1∶1万原生岩石化探数据中17种元素进行分析,获取锡多金属矿致异常信息,再通过变差函数分析异常控制因素,结合本次1∶1万野外地质填图成果,获得如下认识:①F1因子代表Cd-Hg-Pb-Zn元素组合,是中低温热液型多金属矿化的反应;F3代表Sn、Mo元素组合,反映的是岩体及热液的相关信息;F5包括Sn、Sr,Sr是碳酸盐岩的常见元素,反映Sn元素部分来源于个旧组灰岩和法郎组炭质、泥质灰岩。②勘查区东南部异常晕展布特征为串珠状分布且异常浓集中心恰好都位于岩性分段面,推测该区存在隐伏岩体。③该区的断裂控矿性不明显,Sn元素异常展布的空间结构性主要由南西向的地层和该区的隐伏岩体控制。

Identifying and Assessment of Mineralization Information Associated with Sn-polymetallic Mineralization in the Western Gejiu District,Yunnan

The Gejiu mineral district, which is a world class tin production region, is facing a current shortage of resources, therefore, mineral exploration in the deeper and peripheral spaces has become a top priority in this old mine. Douyan district, located in the southest of western district, is becoming the focus of mineral exploration for its favourable metallogenic geologic conditions. In this paper, factor analysis (FA) and spectrum-area fractal model (S-A) are applied to study the integrated primary geochemical anomalies associated with polymetallic Sn mineralization. The results are shown as follows: (1) F₁ consists of positive loading from Cd-Hg-Pb-Zn-W, indicating the meso epithermal deposit associated with polymetallic sulphides. Both F₃ and F₅ include information associated with Sn mineralization. F₅ consists of Sn and Sr (a common element in carbonates), indicating that a part of ore-forming materials came from carbonate country rocks. F₃ consists of Sn and Mo and reflects information about magmatic activities which would provide the ore-forming thermal condition and a part of ore-forming materials. (2) Predictive exploration targets have been made which suit in the Shuitan Mountain in southeast of study area. It is speculated that circum-shaped amomalies around the Shuitan Mountain were related to volcanic rocks and alteration zones. (3) The main controlling factors for enrichment of Sn are granitoid batholiths and wall rocks based on the modeling semi-variogram.