钦-杭结合带南段庞西垌地区Ag-Au致矿地球化学异常信息识别与提取

发布时间：2018-03-06 15:13

本文选题：多重分形奇异性　切入点：空间加权主成分　出处：《岩石学报》2017年03期 　论文类型：期刊论文

【摘要】：基于分形与多重分形理论的非线性化探数据处理方法及以空间加权主成分分析模型为代表的地学多源信息融合技术,为致矿地球化学异常信息的识别和提取提供了有力的工具。本文以钦-杭结合带南段庞西垌地区1∶5万水系沉积物地球化学数据为例,研究如何综合运用多重分形局部奇异性与空间加权主成分分析这两种地学信息处理方法来识别和提取致矿地球化学异常信息。首先,采用滑动窗口的方法绘制了研究区与银金矿化关系密切的五种地球化学元素Au、Ag、Cu、Pb和Zn的局部奇异性指数图以增强局部弱缓异常信息。然后,在控矿条件分析的基础上,运用北东向断裂构造这一重要控矿要素对Ag-Au成矿作用的影响范围,即距离北东向断裂的距离,作为应变量来构建用于空间加权主成分分析的空间权重系数的计算模型,以此来突显化探样品在控矿地质条件约束下的空间相关性。进而,采用空间加权主成分分析方法来得到Au、Ag、Cu、Pb和Zn多元素奇异性指数值的组合异常(第一主成分因子得分)。结果表明:综合运用多重分形局部奇异性与空间加权主成分分析方法可以有效的识别和提取Ag-Au致矿地球化学异常信息,圈定具有示矿意义的多元素组合异常区。
[Abstract]:Nonlinear geochemical data processing method based on fractal and multifractal theory and geoscience multi-source information fusion technology represented by spatial weighted principal component analysis model. It provides a powerful tool for the identification and extraction of ore-causing geochemical anomalies. In this paper, the geochemical data of 1: 50 million water system sediments in the southern part of the Qinghang-Hangzhou combined belt are taken as an example. Two geoscientific information processing methods, multifractal local singularity and spatial weighted principal component analysis, are studied to identify and extract geochemical anomaly information. Using the sliding window method, the local singularity exponents of five geochemical elements, Aug Ag-Cu Pb and Zn, which are closely related to the gold mineralization in the study area, are drawn to enhance the local weak and slow anomaly information. Then, based on the analysis of the ore-controlling conditions, Using the influence range of NE fault structure, an important ore-controlling factor, on Ag-Au mineralization, that is, distance from NNE fault, a model of spatial weight coefficient for spatial weighted principal component analysis is constructed as a strain. So as to highlight the spatial correlation of geochemical exploration samples under the constraints of ore-controlling geological conditions. The spatial weighted principal component analysis method is used to obtain the combined anomaly (the first principal component factor score) of the singularity index values of the Augna AgCU Cu Pb and Zn elements. The results show that the multifractal local singularity and the spatial weighted principal components are used synthetically. The analytical method can effectively identify and extract the geochemical anomaly information of Ag-Au mineralization. Delineate the multi-element assemblage anomaly area with the significance of ore-indicating.
【作者单位】：中山大学地球科学与工程学院;广东省地质过程与矿产资源探查重点实验室;中国地质大学资源学院;中国地质大学地质过程与矿产资源国家重点实验室;
【基金】：中山大学青年教师起步资助计划项目(32110-18811400) 国家自然科学基金项目(41502310) 广东省自然科学基金项目(2015A030310246) 国家重点研发计划项目(2016YFC0600506)联合资助
【分类号】：P632

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