A green future from a contentious past: Gold and critical metals in a historic arsenic mining district Strassegg (Styria)

Metals such as Bi, Co, Sb, Te, and W are needed in large amounts for renewable technologies central to reaching net-zero carbon and have therefore been termed as critical metals by the European Union. A stable supply chain for these raw materials into the EU is urgently needed, especially considering the current geopolitical instabilities. In light of this, domestic production of raw materials is a priority, and we therefore investigate the historic Au-Ag-As mining district Strassegg in the north of Graz (Styria) for precious and critical metals. Our study combines whole rock geochemistry from tailings piles as well as scanning electron microscope (SEM) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of sulfide minerals to show the amount precious and critical metals still present, as well as characterizing in what form these metals are found (i.e., inclusions or lattice bound). Additionally, in-situ calcite U-Pb dating was done for Strassegg and other Au-Cu deposits in the eastern Alps to constrain the age of ore mineralization in the region.