Drilling data constrained resistivity inversion of ERT data and applications for mineral exploration in Inner Mongolia, China

Abstract:

Electrical resistivity tomography (ERT) with borehole-to-surface array employed for mineral explorations in Abag Banner, Inner Mongolia, China. Before the ERT method conducted, the drilling data has been originally measured. By the drilling data, a rough model has been established. The ERT survey line was installed in north-south direction which is perpendicular to the strike direction of mineral vein according the drilling data. In order to study the effect of the drilling data on the inversion resolution, a synthetic resistivity model is carried out. The anomalous body consists of 11 conductivity blocks. We assumed that the drilling data sets are measured from four boreholes. Then, the traditional resistivity inversion and the drilling data constrained resistivity inversion are employed, and the two subsurface resistivity maps obtained. From the maps, the inverted resistivity map by the drilling data constrained resistivity inversion has a better resolution and can describe the anomalous body well, however, the one from the traditional resistivity inversion cannot reveal the subsurface resistivity distribution especially to the depth. By the same way, we conducted traditional resistivity inversion and the drilling data constrained resistivity inversion of field study ERT data, two subsurface resistivity maps obtained. Compared with two resistivity maps, the one from drilling data constrained resistivity inversion have a better resolution, what is more, the maps describe the behaviour of the mineral vein well.