基于对数比变换和分形模型的地球化学异常识别与提取——以云南个旧锡多金属矿集区为例  

Identification and extraction of geochemical anomalies based on log-ratio transformation and fractal model:a case study of Gejiu tin polymetallic deposit area in Yunnan province

作　　者：李壮 LI Zhuang(Faculty of Land Resources Engineering,Kunming University of Science and Technology,Kunming Yunnan 650093,China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093

出　　处：《化工矿物与加工》2024年第10期61-73,共13页Industrial Minerals & Processing

基　　金：昆明理工大学引进人才基金项目(KKZ3202021050)。

摘　　要：覆盖区弱缓异常识别与靶区圈定,是矿产勘查的难点。云南个旧锡多金属矿集区50%以上面积被晚三叠统个旧组灰岩覆盖,属于典型老矿山,有必要开展新一轮找矿工作。本文以个旧锡多金属矿集区为研究对象,利用1∶20万水系沉积物数据,分别进行对数比变换、因子分析、S-A分析和靶区圈定。结果表明:加性对数比变换增强了因子分析的地质解释性,因子F1和F2的元素组合分别代表了酸性岩浆热液高-中-低温叠加的Sn矿化和基性岩浆体系的Cu矿化特征;S-A分析得到的异常区与个旧东西矿床高度契合,证实了S-A分形方法能有效消除“闭合效应”,提高覆盖区的异常识别效率;在未充分探明的异常区,圈定了4个潜在靶区,为后续的锡矿资源勘查提供了科学依据。The identification of weak and gradual anomalies in the coverage area and the delineation of target areas are the difficulties in mineral exploration.More than 50%of the Gejiu tin polymetallic deposit area in Yunnan is covered by Late Triassic Gejiu Formation limestone,which is a typical old mine and requires a new round of exploration work.This article takes the Gejiu tin polymetallic deposit as the research object,and uses 1∶200000 water sediment data to perform logarithmic ratio transformation,factor analysis,S-A analysis,and target area delineation.The results indicate that the additive logarithmic ratio transformation enhances the geological interpretability of factor analysis,and the element combinations of factors F 1 and F 2 represent the Sn mineralization characteristics of acidic magmatic hydrothermal high medium low temperature superposition and the Cu mineralization characteristics of basic magmatic systems,respectively;The abnormal area analyzed by S-A is highly consistent with the Gejiu east and west deposit,confirming that the S-A fractal method can effectively eliminate the"closure effect"and improve the efficiency of anomaly identification in the coverage area;Four potential target areas were identified in the unexplored anomaly zone,providing the scientific basis for subsequent exploration of tin resources.

关 键 词：分形 对数比变换 因子分析 地球化学 异常识别 个旧锡矿 潜在靶区 

分 类 号：P628[天文地球—地质矿产勘探]