Mineralizacja kruszcowa w odkrywczym otworze Sieroszowice S-1 w świetle nowych badań

Abstract

Ore mineralization in the discovery borehole Sieroszowice S-1 in the light of new research.A b s t r a c t. Sieroszowice S-1 borehole was drilled by the Geological Institute under the drilling program conducted by Jan Wyżykowski in the previously unexplored central part of the Fore-Sudetic Monocline, contributing to the discovery of the largest European copper ore deposit. The Zechstein copper-bearing series was reached on 23 March 1957, with the ore mineralization interval at a depth of 656.30–658.26 m. Detailed results of chemical analyses and petrographic investigation were included in the ore deposit geological documentation compiled in 1959, but new research methods currently applicable enable the complementary studies to acquire new results. New findings are based on compilation of reflected-light microscopy, CAMECA SX 100 electron microprobe studies and LEO scanning electron microscope observations. As a result of the supplementary research, the qualitative and quantitative composition of ore minerals along with the indication of their chemical composition in microprobe studies as well as their distribution in the ore-mineralized interval are presented in detail in this paper. Ore mineralization occurs in the shale-carbonate series and it is generally represented by sulphides of Cu-Fe-S system (chalcopyrite, bornite), accompanied by digenite and covellite, occasionally geerite and spionkopite, but one of the ore intervals is dominated by chalcocite associated with bornite. Pyrite, galena and sphalerite commonly accompany copper sulphides, especially in the uppermost part of the copper-bearing series. A few previously unidentified minerals, such as native silver, silver amalgams, and clausthalite have also been identified. The Weissliegend is characterized by oxidative alteration, typical for the Rote Fäule pattern, and contains only relict sulphide mineralization represented by minor chalcopyrite and pyrite locally corroded by hematite. It displays an elevated concentration of gold as well.