Assessment of the Critical Raw Material potential of Denmark

This report reviews the geological potential for critical raw materials (CRMs) in Denmark by assessing possible metallotects, defined as tectonic, geological, mineralogical or geochemical features which play a key role in controlling mineral deposit formation. The review is made despite the uncertainties arising from the existence of only limited data, which was essentially acquired within the scope of hydrocarbon and geothermal exploration, rather than mineral exploration targeting CRMs. Nevertheless, the potential for the Danish subsurface to host CRMs is generally considered to be low. Whereas metallotects favourable for the presence of CRM occurrences do exist, these are often found at significant depth, disrupted, and/or the documented CRM grades are relatively modest. Furthermore, in some instances at least, detrimental chemical associations or inadequate grain size constitute challenges to the economic recovery of CRMs.

The available information suggests a low potential for feldspar and possibly fluorspar (in the Precambrian crystalline basement), vanadium and nickel (in the Cambrian-Ordovician Alum shale), magnesium (in Zechstein potash salts), copper (in the Upper Permian Kupferschiefer mineral system), lithium, boron and magnesium (in formation brines), phosphorus/phosphate rock (in Cretaceous conglomerate and sandstone), silicon (in Miocene silica sands), and titanium (in Miocene-Quaternary heavy mineral placers). Only the potential for helium stands out as being considered to be low to moderate, since the key constituents for a helium kitchen have been documented and the presence of elevated concentrations, of potential commercial interest, of this gas have been confirmed in Denmark, albeit only in one well.