基于断层模型扫描的地质体边界识别方法与应用

The method of geological body boundary identification based on fault model scanning and its application

如何较为准确地确定断层的位置及其产状一直是重力剖面数据解释的重点内容之一。笔者通过构建一系列具有不同几何参数(断层位置与倾角等)的2D断层模型,将其重力响应与观测重力剖面数据进行窗口滑动相关性扫描,根据计算的相关性系数最大值与设置的阈值比较,从而判断在滑动窗口中心点位置下方是否存在断层,若存在,则将相关性系数最大值对应的几何参数作为解释的断层参数。模型试验表明,利用该方法可以识别具有不同倾角的断层。利用该方法对某地区的实际重力剖面数据进行了多角度断层模型的相关性扫描,结果显示根据该方法确定的断层位置及倾角大小与实际断层地质剖面图比较一致,从而验证了笔者所提方法的有效性。

Determining the locations and the dipping angles of the faults is one of the most important issues in the interpretation of the gravity profile data. The authors first construct a series of 2D fault models with different geometric parameters（ e. g.,locations and dipping angles）. Then the theoretical gravity responses of the models are applied to the correlation scanning with the observing gravity profile data in the moving windows. According to the comparison between the calculated correlation values and the threshold value,we can judge whether the faults exist or not beneath the centers of the windows. If the faults exist,the corresponding geometric parameters of the maximum correlation value are treated as the interpretation results. The synthetic model tests suggest that it is effective to identify the faults with different dipping angles. Moreover,the correlation scanning method is applied to an actual profile of the gravity data in field,and the results show that the determined locations and dipping angles of the faults by the proposed method are consistent well with those of the known faults detected by surface geological survey and other geophysical probes. Therefore,both the synthetic tests and the field example indicate the validity of the method presented in this paper.