地球化学分区标准化方法在区域化探信息提取中的应用

THE APPLICATION OF GEOCHEMICAL ZONING STANDARDIZED METHOD TO THE EXTRACTION OF REGIONAL GEOCHEMICAL INFORMATION

从区域化探数据中提取找矿地球化学信息是目前化探工作的重要研究课题,地球化学背景与异常划分是提取找矿地球化学信息的关键。水系沉积物是岩石风化的产物,是上游汇水盆地物质的天然组合,在化学成分上与上游汇水盆地岩石组成具有明显的继承性。水系沉积物中成矿成晕元素含量与常量元素含量之间亦有着密切关系。笔者基于水系沉积物样品特点,采用地球化学分区标准化方法圈定地球化学异常。研究发现,利用常量元素进行地球化学分区是可行的;分区标准化数据处理可以有效地压抑高背景区非矿异常,并强化低背景区矿致异常,突出了找矿信息。以成矿成晕元素标准化数据的因子得分圈定矿化类型综合异常,集中体现了矿致异常信息。

The extraction of ore-prospecting geochemical information from regional geochemical data is an important subject in geochemical exploration, and the division of geochemical backgrounds and anomalies is the key to the extraction of ore-prospecting geochemical information. Stream sediments are weathering products of rocks and natural material assemblages from the upstream catchment basin, thus having obvious inheritance relationship with rocks of the upstream catchment basin in chemical composition. The content of oreforming and halo-forming elements is also closely related to major elements. Based on characteristics of stream sediments, the authors adopted the geochemical zoning standardized method to delineate geochemical anomalies. Case studies show that the application of ma- jor elements to the division of geochemical zones is effective. The false anomaly in the high background area can be suppressed and the mineralization anomaly in the low background area can be intensified by zoning standardized data processing, thus enhancing the prospecting information. The composite mineralization anomalies are delineated by factor scores of ore-forming and major elements, which can make prominent the ore-induced information.