Integrated Interpretation of Geophysical and Soil Geochemical Anomalies in Gold Exploration: Case of Kouremale, Southern Mali-West Africa

Abstract

Detecting the anomalies' sources location in the vast territory such as Kouremale area is a grand challenge for geophysicists because there is a need to assess gold deposit. Therefore, this paper aims to recommend a methodological approach on applied magnetic survey and soil geochemistry to identify the location of anomalies' sources. To that aim the study is divided into phases. In the first phase, the maps for integrated interpretation have been produced by Geosoft Oasis and ArcGIS 10.2.1. The corrected and processed magnetic data with eliminated diurnal variation have been used. Phase two consist of integrate geochemical soil map. The results of phase one identified four magnetic anomalies zones (MAZ) with their coordinates. Thus, the obtained radiometric map, showed that there is a high intensity of K and Th compared to U, which indicates a significant weathering process and there are many saprolithes in study area. The findings of phase two revealed that there is a high concentration of gold content (1500 ppm) with an average concentration of 92 ppm. The integrated interpretation map coming from the combined different maps, referring to the geological information verified on the field, led to conclude that, the target B is the best gold anomaly. The delimitation of the space of the target B from the geophysical and geochemical information confirmed the existence of limited, restricted and potential anomaly.