Application of the ore accumulation coefficient to the interpretation of the structure of MVT Zn-Pb ore deposit (Rodaki - Rokitno Szlacheckie deposit, Poland)

Jaime Jarrin, Marek Nieć


Silesian-Cracow Mississippi Valley-type zinc-lend deposits are confined to the Middle Triassic carbonate rocks. They occur mainly within the “ore-bearing dolomites” replacing limestones. The discontinuity and irregular shape of the ore bodies makes it difficult to study the deposit structure when only the borehole data are available. Ore accumulation coefficient (kr) defined as the ratio of the cumulated ore thickness in the borehole (despite of the number of ore intersections and their hipsometric position) and the thickness of the host ore-bearing dolomite was found to be a convenient tool for deposit modelling. Isarithmic maps of kr values calculated for the mineralized sections defined by the selected cut-off grades make it possible to delimit the mineralized zone and show its structure. The kr values for the cut-off grades of 0.1,0.2 and 0.4% of zinc allow to delimit the zone with the dispersed mineralization confining ore bodies (over 2% Zn) and disclose tectonic control of the ore distribution.

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