NÁLEZ KARBONÁTOVÉ HORNINY V LOMU U OMIC (BRNĚNSKÝ MASIV)
Vol.8,(2001)
Abstract
Keywords:
Brno Massif; faults; tectonics; carbonate rock
A carbonate rock was found in the quarry near Omice. Several small (up to 10 cm) lenses of grey „limestone“ were located within distinct fault structure. Microscopic and cathodoluminescence observations show that the rock is formed by fine-grained calcite which contains several types of larger objects (algal structures, worm borings, relics of the dolomite crystals, clasts of the surrounding crystalline rocks and next unidentified structures). Carbonate rock was affected by both ductile and brittle deformation. The rock has unusual isotopic composition (δ13C = -14.2 ‰, δ18O = -5.2 ‰ PDB). We suppose that the studied carbonate originated in limited, shallow and hypersaline? environment (lagoon, lake?). Structures, oxygen isotope composition and mineral composition were later slightly modified during diagenesis and deformation.
Brno Massif; faults; tectonics; carbonate rock
References
Hanžl, P. - Buriánková, K. (1998): K petrografii a geochemii metagaber od Pucova (moravikum) a z Omic (brněnský masív).- Geol. Výzk. Mor. Slez. v r. 1997, 5, 78-80. Brno.
Hladil, J. - Hladíková, J. (1997): Obsah izotopů 13C a 18O v devonských karbonátech Moravského krasu: specifický sekvenční vzor. - Geol. Výzk. Mor. Slez. v r. 1996, 4, 57-63. Brno.
Moore, C. H. (1989): Carbonate diagenesis and porosity.- Elsevier. Amsterdam.
Slobodník, M. - Muchez, Ph. (1998): Geochemie kalcitových žil v paleozoických horninách Moravského krasu. - Geol. Výzk. Mor. Slez. v r. 1997, 5, 65-68. Brno.
Zimák, J. (2000): Mineralogie hydrotermálních žil v lomech u Hrabůvky a Nejdku (moravskoslezský kulm). - Geol. Výzk. Mor. Slez. v r. 1999, 7, 106-108. Brno.