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Prospectivity analysis of the Polish Kupferschiefer new insightSawomir Oszczepalski Polish Geological Institute-National Research Institute, Rakowiecka 4, 00-975 Warsaw, PolandStanisaw SpeczikPolish Geological Institute-National Research Institute, Rakowiecka 4, 00-975 Warsaw, Poland

Abstract. The resource base of the Polish copperindustry is confined to stratabound Kupferschiefer-typedeposits 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 theLubin-Sieroszowice Copper District) contains a very large volume of ores. Among the potential deposits, particularattention is paid to the areas around existing mines(Kulw, Luboszyce, cinawa West and Wartowice West).Also the areas: Nowiny, arkw and Mirkw are interesting due to accessible depths, Mozw area because of high Cu-Ag grading mineralized body withcredible continuation towards the active mines, as well asthe Sulmierzyce and Janowo areas due to considerableresources and reasonable depth. Taking into accountboth documented reserves of Old and New CopperDistricts as well as reconnaissance resources, it can beestimated that approximately 250-300 Mt Cu and 200-300 thousand t Ag is available in SW Poland for futureoperations, which will be possible, when geological andtechnological barriers (depth, temperature, oil and gas)will meet economic trends in the world market. Keywords. Kupferschiefer, exploration, prospectiveareas, resources, SW Poland

1 IntroductionExploration of the Kupferschiefer mineralization hasbeen carried out in Poland since the discovery of theLubin-Sieroszowice deposit in 1957 (Wyykowski1958). Systematic study of lateral contact of oxidizedand reduced rocks constitutes the key mappableexploration 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 activeonly in the Lubin-Sieroszowice area (New CopperDistrict). Although the available reserves were still large(99 Mt of ore containing 1.4 Mt Cu and 5170 t Ag) in theNorth-Sudetic Trough (Old Copper District), theproduction terminated since 1989. At the end of 2009,the proved reserves in the both districts comprised 1782Mt of ore, which contained 35 Mt Cu and 102 870 t Agup 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 MtCu and 83890 t Ag) grading at 2.1% Cu and 57 g/t Ag inaveraged interval of 3.2 m. In surrounding reservedocumented areas there are additional proved andprobable 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, 70300t Ag) enables possible mine production ranging from 20to 30 Mt of ore per year over 2040 year period.

Gradual depletion of shallow reserves results inexploitation of deeper beds. Progress in undergroundmining at depths exceeding 1250 m (a depth limit foreconomic viability categories in Poland) will make thisapproach effective, profitable and technically possible.2 Prospective areas in SW Poland

Due to increased interest of KGHM PM SA andinternational enterprises in exploration for new copperdeposits, PGI-PBG conducted many years of exploration programs. Subsequent successive cores of 370 archivalboreholes were studied outside the mining districts(Oszczepalski and Rydzewski 1997; Speczik et al. 2007).Present studies allowed the construction of the latestversion of the prospectivity map that presents the limitsof the oxidized (Rote Fule) areas, metal zones and Curesources in SW Poland (Oszczepalski and Speczik2010). Cue (including silver) contours of 35 kg/m2 (at cut off 0.7% Cu) define prognostic areas (Fig. 1).

15 prospects with the ore interval at depth up to 2000m were delineated (Table 1): 3 areas (Kulw, Luboszyce,cinawa Zachd) adjacent to the New Copper District,with total reconnaissance resources of 21.7 Mt Cu, theWartowice West area in the vicinity of the Old CopperDistrict (0.4 Mt Cu) and additional 11 targets (with totalresources about 47.4 Mt Cu) that are located distallyrelative to the Lubin-Sieroszowice deposit. In addition, 6areas (Mozw, Wilcze, Papro, Kaleje, erkw,Florentyna) with rich copper mineralization at depthbelow 2000 m were noted in the northern part of theFore-Sudetic Monocline (some 186.4 Mt Cu).

Examination of the organic material was especiallyvaluable (Table 2). It allowed, in a complimentary way,a precise demarcation of oxidized and ore-bearingreduced areas (e.g., Pttmann et al. 1989; Kucha andPrzybyowicz 1999; Bechtel et al. 2000; Oszczepalski etal. 2002; Oszczepalski and Speczik 2009). Studies of thepresent heat flow were also of high importance (Specziket al. 2007), because they helped to select theprospective areas that fulfill both requirements: (1) thepresence of Cu-Ag and Rote Fule-related noble metalsorebodies hosted by rocks with organic matter of highestmaturity and (2) low values of the present daygeothermal field. Those areas are acknowledged to beeconomically and technologically optimal for foreseenoperation.

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Figure 1. Cu-Ag prospectivity map for SW Poland.

Table 1. Reconnaissance copper resources in SW Poland (without documented Cu-Ag deposits)

Prospective area Area(km2) Depth

(m)Average thickness

(m)Average Cu grade

(%)Cu resources

(Mt) RemarksKulw 132 1503.55 - 1961.68 1.41 2.98 13.8

Depositsproximal to

mining districtsLuboszyce 91 1462.50 - 1545.20 1.66 1.76 6.6cinawa West 16 1200.51 - 1367.40 2.58 1.28 1.3Wartowice West 6 941.27 1463.00 2.90 1.10 0.4Borzcin 9 1496.46 1496.97 0.51 4.91 0.6

Deposits at the depth 2000 m

Kaleje 268 3135.20 - 3136.20 1.00 7.07 47.4Mozw 484 2175.48 - 2537.00 2.14 3.22 83.3Papro 266 2608.88 - 2608.98 0.10 21.48 14.3Wilcze 161 2431.31 - 2431.86 0.55 7.75 17.2erkw 162 3545.70 - 3548.50 2.80 1.38 15.6

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Table 2. Averaged values and ranges of metals, Corg, maceralcomposition, vitrinite reflectance (Ro), and the Rock-Eval indices in SW Poland.Zone Rote Fule Cu Pb-Zn Depth (m) 644-1482 657-1353

687-1961

Cu+Pb+Zn (%) 0.1 6.1 4.1Au (ppb) 1254 3 5 Corg (%) 0.5 5.1 6.3Vitrinite 2 3 4Sapropelic matter 1 8 9 Alginite 1 11 11Bituminite 0 50 44Vitrinite-like matter 68 9 4Solid bitumen 13 1 1Ro (%) 1.02 0.82 0.59HI (mg HC/g TOC) 88 242 285OI (mg CO2/g TOC) 183 34 19Tmax (oC) 449 436 436

3 Concluding commentsThe highest prospectivity in the Fore-Sudetic Monoclineis confined to Kulw, Luboszyce and cinawa Westareas, directly adjoining the New Copper District. Theseareas cover 239 km2 and contain about 21.7 Mt Cu atdepths ranging between 450 and 2000 m. Severaltargeted areas located slightly farther from the Lubin-Sieroszowice deposit (Kouchw, Borzcin, lubw,Mirkw) cover 70 km2 and contain 4.0 Mt Cu at 800-1500 m depth. Other 4 areas in the eastern part of theFore-Sudetic Monocline (Henrykowice, Janowo, Milicz,Sulmierzyce) have total area of 343 km2 and resourcesof 40.8 Mt Cu at depths that range from 1450 to 2000 m.At the ary Pericline two areas: arkw and Czeklinhave been delineated, with a size of about 40 km2 andresources of 1.7 Mt at depth from 1350 to1800 m. Closeto the Old Copper District, two small prognostic areas(Wartowice Zachd and Nowiny) at depth to 1500 m have been fixed.

It should be noted, however, that irregular network ofexamined drill holes tended to overestimate the tonnage, resulting in highly approximate resource evaluation. Tomake the data spacing denser, examination of theavailable cores from more than 300 non-examined archival and new boreholes of the oil and gas industry isbeing carried out in follow-up programs. Localreconnaissance and exploration drilling is also requiredto identify new targets.

The choice between greenfield and brownfieldexploration will depend on strategy and risk toleranceduring the worldwide economic crisis (Thompson and Kirwin 2009). Significant are also the limitations relatedto uneven data distribution and density and unfavorablegeological conditions for expected mining, while theeconomic barriers for production constitute: deeperlevels, higher temperature, thinner sections of theMansfeld type, and oil and gas occurrences.

AcknowledgementsThe authors thank the Ministry of the Environment for support and PGNiG SA for access to drill cores andarchives.ReferencesBachowski C, Kudeko J, Wirth H (2007) Attempts to extend the

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