Ground electrical and electromagnetic methods for deep mineral exploration -- results from the SEEMS DEEP project

TL;DR

This paper presents initial results from ground electrical and electromagnetic surveys at a deep geological site, demonstrating the potential of these methods for imaging mineral deposits several kilometers deep, crucial for future mineral exploration.

Contribution

It introduces a geophysical deep exploration workflow combining electrical and electromagnetic methods for imaging deep bedrock structures in mineral exploration.

Findings

Detection of resistivity and chargeability contrasts at ~1400 m depth

Successful imaging of mafic-ultramafic rocks at several kilometers depth

Validation of geophysical methods for deep mineral exploration

Abstract

The transition towards carbon neutral transportation and energy sources increases the global demand for mineral raw materials while easy-to-find near-surface (\< 200 m) ore deposits are unlikely discovered in well-explored areas such as Europe. In order to increase the mineral exploration success rate, the project SEEMS DEEP (SEismic and ElectroMagnetic methodS for DEEP mineral exploration) develops geophysical deep exploration workflow capable of imaging the bedrock from the surface down to several kilometres depth. In this paper, we present first results from ground electrical and electromagnetic surveys conducted at the SEEM DEEP geological test site, namely the Koillismaa Layered Intrusion Complex in north-eastern Finland. Here, a 1.7 km long hole drilled by GTK intersected mafic-ultramafic rocks with anomalous electrical and chargeability properties at ~1400 m depth, making it an interesting case study to test the ability of such technologies for imaging resistivity and chargeability contrasts at several kilometre depth.