11 th SGA Biennial Meeting Let’s Talk Ore Deposits 26-29 th September 2011 Antofagasta, Chile 295 Prospectivity analysis of the Polish Kupferschiefer new insight S�awomir Oszczepalski Polish Geological Institute-National Research Institute, Rakowiecka 4, 00-975 Warsaw, Poland Stanis�aw Speczik Polish Geological Institute-National Research Institute, Rakowiecka 4, 00-975 Warsaw, Poland Abstract. The resource base of the Polish copper industry is confined to stratabound Kupferschiefer-type deposits that occur at the Zechstein/Rotliegendes transition in the Fore-Sudetic Monocline and North- Sudetic Trough. Latest informations strongly indicate that the Kupferschiefer series in SW Poland (outside the Lubin-Sieroszowice Copper District) contains a very large volume of ores. Among the potential deposits, particular attention is paid to the areas around existing mines (Kulów, Luboszyce, �cinawa West and Wartowice West). Also the areas: Nowiny, �arków and Mirków are interesting due to accessible depths, Mozów area because of high Cu-Ag grading mineralized body with credible continuation towards the active mines, as well as the Sulmierzyce and Janowo areas due to considerable resources and reasonable depth. Taking into account both documented reserves of Old and New Copper Districts as well as reconnaissance resources, it can be estimated that approximately 250-300 Mt Cu and 200- 300 thousand t Ag is available in SW Poland for future operations, which will be possible, when geological and technological barriers (depth, temperature, oil and gas) will meet economic trends in the world market. Keywords. Kupferschiefer, exploration, prospective areas, resources, SW Poland 1 Introduction Exploration of the Kupferschiefer mineralization has been carried out in Poland since the discovery of the Lubin-Sieroszowice deposit in 1957 (Wy�ykowski 1958). Systematic study of lateral contact of oxidized and reduced rocks constitutes the key mappable exploration criteria for the Kupferschiefer-type deposits (Rydzewski 1978; Oszczepalski and Rydzewski 1991; Speczik 1995; Speczik et al. 1997; Oszczepalski 1999; Bachowski et al. 2007; Wirth et al. 2007). At present, the underground ore excavation is active only in the Lubin-Sieroszowice area (New Copper District). Although the available reserves were still large (99 Mt of ore containing 1.4 Mt Cu and 5170 t Ag) in the North-Sudetic Trough (Old Copper District), the production terminated since 1989. At the end of 2009, the proved reserves in the both districts comprised 1782 Mt of ore, which contained 35 Mt Cu and 102 870 t Ag up to 1250 m of depth. In the mining area of New Copper District (Fig. 1), total proved reserves amounted to 1470 Mt of ore (30 Mt Cu and 83890 t Ag) grading at 2.1% Cu and 57 g/t Ag in averaged interval of 3.2 m. In surrounding reserve documented areas there are additional proved and probable reserves (212 Mt ores, 4 Mt Cu and 13810 t Ag). Economically mineable reserves in the Lubin- Sieroszowice District (1194 Mt of ore, 25 Mt Cu, 70300 t Ag) enables possible mine production ranging from 20 to 30 Mt of ore per year over 2040 year period. Gradual depletion of shallow reserves results in exploitation of deeper beds. Progress in underground mining at depths exceeding 1250 m (a depth limit for economic viability categories in Poland) will make this approach effective, profitable and technically possible. 2 Prospective areas in SW Poland Due to increased interest of KGHM PM SA and international enterprises in exploration for new copper deposits, PGI-PBG conducted many years of exploration programs. Subsequent successive cores of 370 archival boreholes were studied outside the mining districts (Oszczepalski and Rydzewski 1997; Speczik et al. 2007). Present studies allowed the construction of the latest version of the prospectivity map that presents the limits of the oxidized (Rote Fäule) areas, metal zones and Cu resources in SW Poland (Oszczepalski and Speczik 2010). Cu e (including silver) contours of 35 kg/m 2 (at cut off 0.7% Cu) define prognostic areas (Fig. 1). 15 prospects with the ore interval at depth up to 2000 m were delineated (Table 1): 3 areas (Kulów, Luboszyce, �cinawa Zachód) adjacent to the New Copper District, with total reconnaissance resources of 21.7 Mt Cu, the Wartowice West area in the vicinity of the Old Copper District (0.4 Mt Cu) and additional 11 targets (with total resources about 47.4 Mt Cu) that are located distally relative to the Lubin-Sieroszowice deposit. In addition, 6 areas (Mozów, Wilcze, Papro�, Kaleje, �erków, Florentyna) with rich copper mineralization at depth below 2000 m were noted in the northern part of the Fore-Sudetic Monocline (some 186.4 Mt Cu). Examination of the organic material was especially valuable (Table 2). It allowed, in a complimentary way, a precise demarcation of oxidized and ore-bearing reduced areas (e.g., Püttmann et al. 1989; Kucha and Przyby�owicz 1999; Bechtel et al. 2000; Oszczepalski et al. 2002; Oszczepalski and Speczik 2009). Studies of the present heat flow were also of high importance (Speczik et al. 2007), because they helped to select the prospective areas that fulfill both requirements: (1) the presence of Cu-Ag and Rote Fäule-related noble metals orebodies hosted by rocks with organic matter of highest maturity and (2) low values of the present day geothermal field. Those areas are acknowledged to be economically and technologically optimal for foreseen operation.