Main Precambrian and Paleozoic Mineral Resources of Estonia

Abstract

Estonia is rich in mineral resources. For example, oil shale usage has over 100 years of history and Estonia holds, the largest in Europe, unused sedimentary phosphate rock reserves, about 3 Billion metric tons ore (ca 819 Million metric tons of P 2 O 5 ). The phosphate content in fossil shells (phosphorite) ranges 35-37 wt% P 2 O 5 . These shells are relatively enriched by rare earth elements, where the total rare earth metals reach 3600ppm. The phosphates are overlain by metal-enriched black shale-graptolite argillite. Calculated tonnage of elements in the black shale is uranium-5.6656 Million tons (6.6796Mt as U 3 O 8 ), Zinc-16.5330Mt (20.5802Mt as ZnO), vanadium-47.7538Mt, molybdenum-12.7616Mt (19.1462Mt as MoO 3 ) and thorium tonnage in between 0.213-0.254Mt. Estonian oil shale-kukersite deposits cover up to 5,000km 2 . The total kukersite resources in Estonia are estimated to be about 4.627 Billion tons. Several metal occurrences are known in the Paleoproterozoic basement of Estonia. In NE Estonia, magnetitegneisses (up to 45 % total iron), sometimes enriched in Mn (up to 6 wt%) are found in Jõhvi complex and in several locations elsewhere. Historical drillings have shown that the complex of magnetite-rich rocks is about 100m thick, and the reserves of iron ore (Fe over 25%) are about 355 Million tons (calculated to depth of 500m), 629 Million tons if calculated to the depth of 700m and 1500 Million tons if calculated to the depths of 1000m. However, this needs to be confirmed by modern exploration.