The paper presents results of new petrographic and mineralogical analyses of Ediacaran clastic rocksin the Bibiela PIG-1 borehole drilled in 2016. Three types of microlithofacies have been distinguished. The basic types of rocks are siltstones and claystones containing thin layers of mudstones. Breccia is common, while sandstones form thin packages. The Ediacaran rocks are cut by numerous veins that intersect each other. They are filled with carbonates, quartz, chlorites and kaolinite. Ankerite, Fe-dolomite, dolomite, Mg-siderite (sideroplesite, pistomesite, metisite), Mn-siderite (manganosiderite) and Fe/Mn-calcite were identified among the carbonate minerals. Vitrinite reflectance index Ro (1.68%), Kübler index KI (0.72 to 1.10 Δo2ϴ CuK2) and smectite content (10-25%) in the mixed-layer illite/smectite indicate that the Ediacaran rocks in the Bibiela PIG-1 borehole have been altered under the conditions of late diagenesis at the maximum temperature estimated at approx. 160oC
In the northern part of the Upper Silesian Block, there is a latitudinal structure, several kilometres wide, stretching from Zawiercie through Siewierz towards Tworóg, where Devonian carbonate formations occur directly under the Triassic overburden. This tectonically controlled elevated structure, redefined in this paper as the Brudzowice (Siewierz) elevation, is the effect of Variscan restructuring of the area, which was accompanied by magmatism carrying polymetallic mineralization, and by intense erosion reaching the Lower Devonian formations. The Bibiela PIG-1 borehole, drilled in 2016, revealed the presence of Ordovician and Ediacaran clastics under the Devonian, in which metasomatic changes and ore mineralization located within the range of low-temperature hydrothermal effects associated with an acid magmatic intrusion were observed. A complex ore association with Cu, Fe, Zn, Pb, and Ni and As minerals have been found. The presence of chalcopyrite extends the list of documented manifestations of copper mineralization in the Upper Silesian Block, so far observed in the late Paleozoic and Lower Triassic formations, thus indicating the prospect for further exploration in this area.
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Ujęcie wód podziemnych Bibiela funkcjonuje od ponad 50 lat i jest jednym z największych ujęć w rejonie Górnego Śląska. Intensywna eksploatacja wód spowodowała głębokie obniżenie zwierciadła wody węglanowego kompleksu triasowego na obszarze około 350 km2. Skomplikowana budowa geologiczna w rejonie ujęcia oraz zmienne warunki hydrodynamiczne wpływają znacząco na przestrzenne i czasowe zróżnicowanie składu chemicznego wód. Celem pracy była ocena stanu rozpoznania składu chemicznego wód węglanowego kompleksu wodonośnego triasu w związku z długotrwałym obniżeniem zwierciadła wody. W tym celu przeanalizowano wyniki ponad 5000 archiwalnych analiz chemicznych wód z 22 studni ujęcia Bibiela z lat 1956–2009. Przy użyciu programu AquaChem zintegrowanego z programem Phreeqc obliczono wskaźniki nasycenia badanych wód względem kalcytu, dolomitu i gipsu
EN
The Bibiela well field is one of the biggest intakes in the Upper Silesian region, extracting groundwater from the Triassic carbonate aquifer. The paper describes groundwater chemistry based on over 5000 chemical analyses of water from 22 wells from the years of 1956–2009. Saturation conditions of water with respect to calcite, dolomite and gypsum were calculated by means of AquaChem software combined with Phreeqc. Chemical composition of considered groundwater shows spatial and temporal variability mostly due to complicated geology. Intensive groundwater exploitation caused water table lowering of about 70 m, what changed hydrogeochemical conditions and caused some processes to happen or intensify. The most probable process is calcite and dolomite dissolution but also dedolomitization due to inflow of water enriched with SO4 and Ca ions from the dissolution of gypsum.
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