论文部分内容阅读
针对金矿化的具体地质特征，研究了确定背景值、异常下限和异常分级的一套方法。在大比例尺基岩地球化学勘查中，应用目标追踪法，分别采集了背景场和异常场两类介质［１］。在确定背景值、异常下限时，将每类介质中的全部样品测试结果，按ｘ＋３ｓ公式剔除到不能再剔除为止，使剩余样品在基本服从正态分布的前提下，取其平均值作为背景值；最后一次被剔除样品的平均值作为异常下限；在每次被剔除样品的平均值中，选择与上下相邻变化梯度显著的平均值作为异常分级的界线值；并将它们与地质特征相联系，使地球化学异常圈定中最重要的３个参数被赋予地质涵义，分级界线与金的成矿阶段相对应，对异常的评价能够得到正确的结论。
Aiming at the specific geological characteristics of gold mineralization, a set of methods to determine the background value, abnormal lower limit and abnormal grading were studied. In large-scale bedrock geochemical exploration, the target tracking method was used to collect two kinds of media, background and anomaly [1]. When the background value and the abnormal lower limit are determined, the test results of all the samples in each type of medium are eliminated according to the formula of x + 3s until they can not be eliminated again. Under the premise of basically obeying the normal distribution, the remaining samples are taken as the background value ; The average value of the last sample to be rejected is taken as the lower limit of abnormality; and among the average values of the samples to be rejected, the average value of the gradient adjacent to the upper and lower sides is selected as the boundary value of the abnormal classification, and the geological characteristics are associated with them , The three most important parameters in delineation of geochemical anomalies are given geological connotations. The boundary of demarcation corresponds to the metallogenic stage of gold, and the correct evaluation of abnormalities can be concluded.