滇东南薄竹山—老君山矿集区Sn-W与Pb-Zn-Ag矿致异常提取及其找矿靶区圈定

发布时间：2018-05-09 21:47

本文选题：主成分分析 + 二维经验模分解　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：薄竹山-老君山矿集区位于个旧-大厂锡钨多金属成矿带中段,发育了一系列包括白牛厂、官房和都龙在内的世界级锡-钨及银-铅-锌多金属矿床。本文基于滇东南薄竹山-老君山地区1∶20万化探扫面数据,利用主成分分析法和二维经验模分解方法,提取该区Sn-W和Pb-Zn-Ag的矿致异常并圈定找矿靶区。通过研究得出如下结论:(1)主成分分析能够确定元素之间的内在联系并确定成岩、成矿元素共生组合,而因子得分图可以从空间上揭示元素组合异常与地质体(地层、岩体、矿体)的空间分布关系。滇东南地区存在三种因子组合:(1)[Fe2O3-Ti-Cr-V-Ni-Co-Al2O3-Cu-Nb-Y-Zn-Mn]—-[SiO2],正载荷为Fe2O3-Ti-Cr-V-Ni-Co-Al2O3-Cu-Nb-Y-Zn-Mn代表了研究区的亲基性岩石组合;负载荷为SiO2,表明在地质演化过程中,随着SiO2含量增加,上述元素组合含量逐渐降低;(2)Bi-W-Sn-As-Pb组合代表了研究区中高温热液成矿元素组合(如个旧和官房W-Sn多金属矿化);(3)[Sb-Hg-As]—-[Na2O-Sr]可能代表某种矿化的低温热液元素组合;(4)Ag-Cd-Zn-(Pb)组合代表了研究区典型中低温热液成矿元素组合(如白牛厂超大型Ag-Cd-Zn-Pb多金属矿化,都龙超大型锡多金属矿化)。(2)本文共圈定两个钨锡成矿有利地段,两个地段均位于花岗岩与围岩的内接触带中,推测是因为岩浆的上侵作用,导致岩体周围形成了大量的张性裂隙,岩浆热液沿着裂隙和岩层层面运移并与围岩充填交代,最后矿化形成岩体周边的脉状、细脉带。(3)银铅锌高异常区除了沿燕山期花岗岩与围岩的接触带分布,还受到北东向、北西向、南北向的三级断裂控制,表明区内构造对矿化的富集具有明显的控制作用,这些三级断裂和层间破碎带可作为重要的容矿通道。因此具有组合元素异常的三级断裂、破碎带与接触带是寻找银铅锌矿床的有利地段。(4)结合两种方法对地球化学数据进行处理,不仅成功获取了成矿元素组合,还发现已知矿点、构造、岩体等地质要素与分解的地球化学异常图具有较高的吻合度,证明了这两种方法能够准确有效地提取化探元素异常并圈定成矿有利地段,应结合两种方法圈定找矿靶区,为找矿工作提供科学的依据。
[Abstract]:The Paozhushan-Laojunshan ore concentration area is located in the middle of Gejiu-Dachang tin-tungsten polymetallic metallogenic belt and has developed a series of world-class tin-tungsten and silver-lead-zinc polymetallic deposits including Biniuchang Guanfang and Dulong. Based on the 1: 200 000 geochemical sweep surface data of Bao-zhushan-Laojunshan area in southeastern Yunnan, the ore induced anomalies of Sn-W and Pb-Zn-Ag in this area are extracted by principal component analysis and two-dimensional empirical mode decomposition method, and the ore-prospecting targets are delineated. The conclusion is as follows: (1) Principal component analysis (PCA) can determine the intrinsic relationship between elements, diagenesis, symbiotic assemblage of metallogenic elements, and factor score map can reveal the anomaly of element assemblage and geological bodies (strata, rock mass, rock mass) spatially. The spatial distribution of the orebody. In southeastern Yunnan, there are three kinds of factor assemblages: [Fe2O3-Ti-Cr-V-Ni-Co-Al2O3-Cu-Nb-Y-Zn-Mn]-[SiO2]. The positive load of Fe2O3-Ti-Cr-V-Ni-Co-Al2O3-Cu-Nb-Y-Zn-Mn represents the basophilic rock assemblage in the study area, and the loading load is Sio _ 2, which indicates that during the geological evolution, the content of SiO2 increases with the increase of the content of SiO2. The decrease of the content of the above element assemblage gradually indicates that the Xian2Bi-W-Sn-As-Pb assemblage represents the low temperature hydrothermal metallogenic element assemblage (such as Gejiu and Guanfang W-Sn polymetallic mineralization) [Sb-Hg-As]-[Na2O-Sr], a low temperature hydrothermal element assemblage that may represent some mineralization, and represents the low temperature hydrothermal element combination of 4Ag-Cd-Zn-Pbb, for example, Gejiu and Guanfang W-Sn polymetallic mineralization. The typical middle-low temperature hydrothermal metallogenic element assemblage (such as bainiuchang super-large Ag-Cd-Zn-Pb polymetallic mineralization) in the study area was studied. Dulong super-large tin polymetallic mineralization. 2) this paper delineates two favorable areas for tungsten and tin mineralization, both of which are located in the inner contact zone between granite and surrounding rock, presumably because of the magma transgression. As a result of the formation of a large number of tensional fractures around the rock mass, magmatic hydrothermal fluid moves along the fissures and strata and fills up with the surrounding rocks, and finally mineralizes to form veins around the rock mass. In addition to the distribution along the contact zone between granite and surrounding rock in Yanshanian period, the Ag-Pb-Zn high anomalous area is also controlled by the third-order faults in the NNE, NW and NNE directions, indicating that the tectonics in the region have an obvious controlling effect on the mineralization enrichment. These three-order faults and interlayer fracture zones can be used as important ore-bearing channels. Therefore, the third order fault with assemblage element anomaly, fracture zone and contact zone are favorable areas for finding silver, lead and zinc deposits. The geochemical data are processed by combining two methods. Not only the metallogenic element assemblage is obtained successfully, but also the known ore points are found. The geological elements such as structure and rock mass have a high degree of agreement with the geochemical anomaly map of decomposition, which proves that these two methods can extract geochemical element anomalies accurately and effectively and delineate favorable metallogenic areas, and should be combined with two methods to delineate ore-prospecting target areas. To provide scientific basis for prospecting work.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.2

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