The organization of the Geological Survey of Finland (GTK) has carried out a valuation of yet undiscovered mineral resources in the bedrock of Finland since 2008. As part of this process, the extent of lithium resources in the case of undetected pegmatite deposits of lithium-caesium tantalum (LCT) was also estimated to one kilometre in 2018.
The most well-known LCT pegmatite-lithium stores in Finland are all within or close to the border with Kaustby municipality in central Ostrobothnia. The identified resources in these six deposits at the time of assessment at the end of 2017 amounted to approximately 46,000 tonnes of lithium. The discovered and reported resources have since increased to about 58,000 tonnes of lithium (Keliber Oy 2018).
The number of possible, but not yet discovered, LCT pegmatic stocks was estimated by GTK experts at 7.
The so-called Monte Carlo simulation estimate indicates that the undiscovered stocks contain, with a 50% probability, at least 510,000 tonnes of lithium. More than 90 per cent of the estimated undiscovered lithium resources in Finland are located either in the immediate vicinity of Kaustby or in the surrounding larger Järvi-Pohjanmaa area.
The assessment results show that at least 90 per cent of the remaining lithium quotas within the top one-kilometre thick layer of the Finnish bedrock are in poorly investigated or completely unknown deposits.
