甘肃省席芨水地区遥感蚀变信息提取及找矿远景分析

Remote Sensing Alteration Information Extraction and the Prospecting Perspectives Analysis in Xijishui Area of Gansu Province

摘要:

在地质工作程度较低、基岩出露较好的地区，充分重视遥感数据的使用，可有效地缩小工作靶区，提高找矿效率。该文以甘肃省席芨水地区为研究区，基于ETM+遥感数据，利用多元数据分析、准归一化、掩膜分析、主成分分析、密度分割等方法，从Landsat7 ETM+数据中提取金矿化蚀变信息。在遥感地质解译的基础上，充分分析提取的羟基异常和铁染异常，结合区域地质特征、区域成控矿条件及区域物化探异常特征等，尽可能去掉假、弱异常。结果表明：该方法能有效消除植被、水系、阴影等干扰信息的影响，从遥感数据载体中提取微弱的金矿化蚀变信息。提取的矿化蚀变信息与断裂构造具有较好的相关性，主要分布于断裂构造交会处、断裂与岩体交会处等成矿优势部位，对今后的找矿工作具有一定的指导意义。

Abstract:

In areas where geological work is relatively low and bedrock is well exposed, the use of remote sensing data should be paid enough attention. Thus, the working target area can be effectively reduced and the efficiency of prospecting can be improved. In this paper, taking Xishui area in Gansu province as the study area, based on ETM+ remote sensing data, by using multivariate data analysis, normalization, mask analysis, principal component analysis, density segmentation method, extraction of gold deposit from Landsat7 ETM+ data information. On the basis of remote sensing geological interpretation, the extracted hydroxyl anomalies and iron stain anomalies have been fully analyzed. Combining with regional geological characteristics, regional metallogenic conditions and the characteristics of regional geophysical and geochemical anomalies, the fake and weak anomalies can be removed as far as possible. It is showed that this method can effectively eliminate the influence of disturbance information, such as vegetation, water system and shadow, and extract faint gold mineralization alteration information from remote sensing data carrier. The mineralized alteration information extracted has a good correlation with the fracture structures, and mainly distributed in the metallogenic dominant position of fault structure intersection, fracture and rock mass intersection, which has a certain guiding significance for prospecting work in the future.