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.
Detrital zircon age of the conglomerates from the Upper Silesian (USB) and Małopolska (MB) (S Poland) have been investigated to compare their deposition age and possible provenience. The size and poor sorting of the lithoclasts reflect a short transportation, with deposition close to the sourceland. The Late Ediacaran conglomerate of the Potrójna IG 1 and Raciechowice 1 boreholes (USB) reveal a good match between the ages known from the local basement explored by boreholes. Detrital zircon clusters in a range of 579-585 Ma and 628-638 Ma and of 707 Ma are consistent with the distributions of Cadomian magmatism within the nearest orogenic belt or those identified elsewhere within the Brunovistulicum. In case of the conglomerate deposited in the Batowice 2 borehole (MB), the zircon clusters of 532, 551, 594 and 649 Ma, accompanied with a pre-Svecofennian group peaked at 2071 Ma, and the lack of Sveconorvegian population may document a tectono-sedimentary interaction between the Baltica's southern margin and the Gondwanan Cadomian and Late Cadomian basement during Early Paleozoic time. This conglomerate bed was deposited later, after the Early Ordovician, then docking of Małopolska Block - Baltica was probably completed.
Borehole Cianowice-2 was drilled several kilometers to the NW of Kraków. Under the Jurassic deposits, at a depth of 265.3-600.0 m, Ediacaran clastic sediments with polymetallic mineralization represented by a group of dozen ore minerals, mainly sulphides and sulphosalts were found. This is low-temperature, hydrothermal mineralization, which along with local metasomatic transformations indicates that the Ediacaran rocks are probably related to the nearby intrusion of acid igneous rocks. In order to locate this hypothetical intrusion, detailed gravimetric and magnetic tests were performed. As a result, a negative gravimetric anomaly was discovered with minima in the region of Maszyce and Pr¹dnik Ojcowski. An optimal borehole location for a further exploration was proposed near the Podmaszyckie hamlet at a depth of about 1000 m.
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