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Dariusz Sala and Grzegorz Rzepa

Geochemistry of waters and bottom sediments in landslide lakes in Babiogórski National Park

The aim of this work was to assess the contamination of the landslide lakes located within Babiogórski National Park. For this purpose, samples of water and bottom sediment from 12 lakes were collected. Chemical analyses of the waters (including main cation and anion concentrations, trace-metal levels and selected physicochemical parameters) and of the sediments (including heavy metals) were performed. The waters are acidic to neutral and are characterized by low mineralization. Concentrations of trace elements are commonly low. Elevated levels of Fe, Mn and Al are probably related to natural geochemical processes. The sediments are strongly contaminated by Cd, whereas other trace metals levels are at their hydrogeochemical background. The high level of Cd contamination is most probably related to long-range industrial emissions.

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Piotr Bożęcki, Grzegorz Rzepa and Tadeusz Ratajczak

Abstract

This work presents the results of microbiological investigations carried out in the Polish part of the Muskau Arch. In this abandoned lignite mining area highly acidified Fe-rich waters have been formed as a result of sulphide oxidation. Microbiological tests have shown that all studied groups of microorganisms exhibit both time and spatial variability. The most common group of microorganisms are bacteria Galionella sp.

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Bożena Gołębiowska, Grzegorz Rzepa and Adam Pieczka

Abstract

In the Permian rhyodacite quarry at Zalas near Krakow, southern Poland, thallium-bearing Mn oxides occur in a small fault zone cutting Middle Jurassic sandy limestone poorly encrusted by an oxidized polymetallic mineralization. The encrustation comprises sulphides (pyrite, chalcopyrite, chalcocite, covellite, galena, marcasite), native bismuth, hematite, goethite, cuprite, mottramite, iodargyrite, unrecognized Cu sulphates and Bi oxychlorides as supergene minerals, barite and rare tiny grains of gold. It is most likely connected with rejuvenation of Early-Paleozoic faults during the Alpine orogeny on the Oligocene–Miocene boundary. Rare Tlbearing Mn oxides occur in an outside zone of the encrustations, filling small fractures and voids in limestone forming the fault breccia. Tl contents, reaching 20.82wt% as Tl2O, exceed by more than two orders of magnitude those reported in similar minerals before, making the oxides unique on a world scale. The Tl-bearing Mn oxides from Zalas reflect intensive weathering of an older Tl-bearing sulphide mineralization in an arid climate, involving saline fluids delivered to the groundwater system as the nappe structure of the Carpathians was developing during the Sava tectonic phase Oligocene/Miocene boundary.

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Jacek Matyszkiewicz, Alicja Kochman, Grzegorz Rzepa, Bożena Gołębiowska, Marcin Krajewski, Krzysztof Gaidzik and Jerzy Żaba

Abstract

A spectacular epigenetic silicification was encountered in the Oxfordian bedded limestones exposed in the Sokole Hills situated in the Krakow-Częstochowa Upland. The main epigenetic mineral is microcrystalline quartz accompanied by minor goethite, hematite, barite, galena and sphalerite. Locally, the mineralized limestones reveal Pb and Cu contents exceeding over 150 times the background values of these metals in unmineralized limestones.

The epigenetic mineralization of the bedded limestones was probably a two-stage process. During the first, Early Cretaceous stage, silicified limestones formed at the erosional surface of a denuded carbonate complex. Such silicification greatly limited the progress of the first karstification phase of the Upper Jurassic carbonates initiated in the Hauterivian. The sources of silica accumulated in the limestones were descending solutions enriched in silica derived from the weathering zone. This silicification affected the topmost part of the Upper Jurassic massive limestones and the deeper portions of the bedded limestones along the fracture systems and stylolites.

Early Cretaceous tectonic activity generated new dislocations and re-opened the existing faults, which were subsequently filled with permeable Albian quartz sands. These openings became the migration pathways for ascending, warm, relict, sulphide-carrying hydrothermal solutions at the second formation stage of the epigenetic mineralization. The newly supplied silica from the Albian sands precipitated on the silicified limestones and, as concentric rims, on brecciated, early diagenetic cherts. The second-stage mineralization proceeded under phreatic conditions, presumably close to a fluctuating mixing zone of ascending, warm hydrothermal solutions and descending cold groundwaters. The brecciated cherts acting as silica crystallization nuclei indicate that the last mineralization stage probably followed the final phase of Cenozoic faulting