内蒙古西部朱拉扎嘎金矿遥感蚀变异常与化探异常对比研究

Comparative Analysis between the Altered Rock Anomaly Extracted from ETM^+ and the Geochemical Anomaly in the Zhulazhaga Gold Deposit of Western Inner Mongolia

本文以朱拉扎嘎金矿为例,应用遥感技术,对比分析朱拉扎嘎金矿遥感蚀变异常、化探异常的提取过程和分布特征,认为:1.遥感蚀变异常位于化探异常中心与矿体吻合关系好,可作为找矿标志,应用于化探异常筛选可增加其成矿有力度的判别;2.遥感蚀变异常定位精度高,异常范围小,更接近矿体,应用于化探异常查证可以提高查证效率。该方法技术适合于寻找与热液活动有关的金属矿产,在基岩出露好,植被稀少的干旱地区效果好,建议在我国西北部荒漠景观区开展应用遥感技术评价化探异常的找矿工作。

The purpose of this study is to present a method to evaluate regional geochemical anomalies at low cost and with high accuracy. Regional geochemical anomalies contain abundant information for ore - exploration. Evaluating regional geochemical anomalies by conventional methods needs much money and longer time, so that this study is important for ore - exploration. Taking Zhulazhaga gold deposit as an example, the comparative analysis of extraction processes and distribution features between remote sensing anomalies and geochemical anomalies in the Zhulazhaga gold deposit shows：firstly, the altered rock anomaly extracted from ETM^＋ is in perfect conformity with ore -body, so it can be employed as a ore -exploration parameter; secondly, the detected extension of altered rock anomaly is smaller than that of 1 ： 50 000 regional geochemical anomaly, so the altered rock anomaly is more close to ore - body, and can lead fieldwork to the areas of altered rocks which may associate with ore - body. We conclude here that evaluation geochemical anomalies using remote sensing altered rock parameters are helpful for geochemical anomaly selection and locating of the fieldwork. The method is available for hunting hydrothermal metal deposits. The authors suggest that evalua- tion geochemical anomalies using altered rock parameter from ETM^＋ for ore -exploration should be carried out in the northwestern China, where the climate is arid. It is because that the poor vegetation covers and abundant outcrops make it is easier for exploring in the arid area when using remote sensing study.