‘If previously the research on the Estonian crystalline basement focused on the occurrence of iron ore and sulphide mineralisation, then recent studies have revealed that mineral genesis and the related spectrum of elements is much broader. It has also been confirmed that modern methods allow for the discovery of new findings from previously examined drill cores,’ explained Siim Nirgi, Senior Geologist at the Department of Mineral Resources of the Geological Survey of Estonia.
Due to the digital and green transition, the elements found in the earth’s crust that are used, for example, in renewable energy and battery technologies have become more important. The global geopolitical situation has changed, as a result of which ensuring Europe’s economic security and the availability of critical raw materials is also in the interests of Estonia. ‘In the context of research on the earth’s crust, this means that instead of focusing on a few well-known combustible mineral resources, we need to find new deposits containing elements that were previously of lesser interest. Considering the connection of the genesis of the crystalline basement of Estonia to southern Finland and the Bergslagen region in Sweden, there is reason to search for the raw materials found in these areas in our earth’s crust as well. The last time attention was paid to crystalline rocks at the national level was more than 30 years ago, but in the meantime both the research methods and the demand for raw materials in society have changed,’ added Siim Nirgi.
A research roadmap for the systematic exploration of mineral resources in crystalline rocks was drawn up at the initiative of the Geological Survey of Estonia. This roadmap provides an overview of the current situation, explains the geological preconditions and outlines a comprehensive action plan for future research.
The focus of prospecting and exploration of potential mineral resources in the crystalline basement of Estonia is on mineral resources that have a comparable likelihood of occurrence to those found in the mineralised provinces of Fennoscandia, a region with a similar crystalline basement. Based on the 2021 report by Nordic geological surveys, which described the potential occurrence of strategic raw metals necessary for the digital and green transition and other economically important mineral resources in the Nordic countries, the prospecting and exploration of the following metals in the context of the geological structure of the Estonian crystalline basement is justified: bismuth, cobalt, indium, nickel, lithium, tantalum, niobium, silver, tungsten, gold, copper, rare earth elements and platinum-group metals.
The proposed activities are organised into stages, which are further divided into two sub-themes: petrographic and geochemical analysis of crystalline rocks, and structural and geophysical field analysis. At present, the Geological Survey of Estonia has already started to implement the first stages which involve the digitalisation of the geochemical and mineralogical database of crystalline rocks, the analysis and interpretation of data and the scanning of the chemical and mineralogical composition of prospective drill cores.
Additional information:
Siim Nirgi
Phone: +372 5332 1856
Email: [email protected]
