衬度返回法在平抑地球化学系统偏倚中应用

Application of contrast return method in stabilizing geochemical system bias

在进行1∶10万、1∶25万、1∶50万或更小比例尺地球化学编图时,由于分析单位和工作时间不同,不同的1∶5万、1∶20万图幅间或同图幅不同批次间的化探数据常存在着系统偏倚。因此,编图前必须进行系统偏倚平抑。目前,系统偏倚平抑方法有衬度变换法、平差法、分幅标准化法、分区标准化法、基准单元系数法和边界极限原理法等。笔者在实际工作中,通过反复试验确认"衬度返回法"是图幅间或批次间系统偏倚平抑的一种实用且有效的方法。

During 1 ： 100000,1 ： 250000, 1 ： 500000 or smaller-scale geochemical mapping, it is usually found that there ex- its system bias of geochemical data between different scales of maps of 1：50000 and 1：200000, or between different batches of data of same scale maps, as a result of difference in analyzing unit and work time. So, system bias must be resolved before mapping. System bias stabilizing methods include contrast variation method,compensation method,map- by-map standardization method, zoning standardization method, reference unit coefficient method,border limiting princi- ple, etc.,of which, based on work experiences and repeated experiments by the authors,the contrast return method is confirmed to be practical and effective in putting down system bias between different-scale maps or between different batches of data of same-scale maps.