2024

Heinonen, Suvi; Laakso, Viveka

In Fennoscandia, the era of easy-to-find outcropping ore deposits discoveries has ended, while enhanced exploration success is required to meet the climate and digital objectives of modern society. This prompts the geoscientific community to develop novel technologies for deep subsurface imaging. Seismic reflection methods, adapted from hydrocarbon exploration to crystalline bedrock, offer superior resolution at depth for imaging complex geology typical for hardrock formations hosting mineralisation. In Finland, crustal scale seismic images provided new insights into the Precambrian bedrock, laying a foundation for mineral system approach in exploration. High-resolution seismic reflection profiles have demonstrated their utility in identifying rock interfaces and subsurface structures in important mining and mineral exploration districts including volcanogenic multimetal massive sulphides as well as mafic intrusions hosting Ni-Cu-PGE and Chromium deposits in Fennoscandia. Drill hole data and petrophysical measurements complement seismic surveys by offering a solid basis for interpretation. Seismic data integrated with geological information enable the creation of 3D geological models that improve the understanding of mineral systems, thus enabling efficient exploration strategies.