Application of joint inversion of Wenner and pole–dipole arrays in limestone exploration

Abstract

Direct current (DC) resistivity method is one of the means to explore karst areas, which has the advantages of a precise exploration target, high construction efficiency, and powerful anti-interference ability. However, the types of DC resistivity method arrays are complex, in situ exploration, different arrays are suitable for different exploration targets, which will greatly affect the construction efficiency. By generating anomaly bodies to demonstrate the various reactions of various arrays, this study compares and contrasts the benefits and drawbacks of the pole–dipole array and the Wenner array. The findings demonstrate that the Wenner array has a relatively shallow exploration depth, a reasonably good effect on surface-level anomaly identification, and a poor effect on deep-level anomaly detection; pole–dipole array has relatively large exploration depth and relatively high resolution to the deep anomalous areas. Based on this, a new data type known as multiple array data is incorporated by superimposing the data from two arrays. The following inferences are made from the inversion results: multiple array can not only retain the maximum investigation depth of single arrays, but also respond to anomalous areas better than any single arrays. Moreover, the reliability of multiple array data is further verified by an example of limestone exploration, therefore providing basis for field survey.