Lóránt BÍRÓ¹, Márta POLGÁRI² & Elemér PÁL-MOLNÁR^1
1Szeged University, Department of Mineralogy, Geochemistry and Petrology, H-6702 Szeged, Egyetem str. 2, (birolori@gmail.com)
²Institute for Geochemical Research, Hungarian Academy of Sciences, H-1112 Budapest, Budaőrsi str. 45,

THE REVALUATION OF THE DRILLINGS OF THE MANGANESE MINERALIZATION IN EPLÉNY (HUNGARY)

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During our work, the layers of 233 drillings that were made in order to explore manganese ore (79 deep drillings and 154 drillings that were in the mine) have been revaluated. These drillings became deeper between 1949 and 1975 as a result of the mining that was running in these times. Fortunately, then the data remained complete and in this way facilities were provided to revaluate them lithologically as well as stratigraphically. The footwall formations constitute a continuous sedimentary sequence with the overlying Úrkút Manganese Formation in the area of Eplény-basin. In the studied area the primary oxidized manganese ore is the most characteristic, while towards to W radiolarian clayey marl occurs. In the Eplény-basin the manganese ore reaches its maximum thickness (21 m) at the intersection of tectonic lines. Although the low-grade carbonate manganese ore appears in some drillings, however according to quantity and quality, the high-quality oxidized manganese ore was mined (~28 w/w% Mn, ~8-9 w/w% Fe, Si, and ~0.2 w/w% P). As a result of our investigation the high quality, boulderly, coarse oxidized manganese ore occurs at the bottom of the manganese ore deposit, while towards the younger layers the Mn concentration decreases. In the Early Cretaceous and in the Middle Eocene the manganese sequence was redeposited which is spatially separable. While the Albian redeposition is in the southern part of the Eplény-basin, the Eocene redeposition is characteristic in the entire basin. This work is the first one that integrates the formations that were intersected by the drillings in Eplény into litostratigraphic units and preserves the archive drilling information in the standard drilling database.