ARTYKUŁY I KOMUNIKATY NAUKOWE Określanie zmienności mineralogicznej utworów kajpru za pomocą metod petromagnetycznych
Abstract
Determination of mineralogical variability of Keuper deposits using rock magnetic methods.
A b s t r a c t. Measurements of the magnetic susceptibility (MS) in sedimentary sequences can quickly provide information on the variability of their mineral composition. A typical application of MS is the reconstruction of the supply of terrigenous material in carbonate rocks or the variability of the ratio of ferromagnetic to paramagnetic / diamagnetic minerals in clastic rocks. The article discusses the practical aspects of using the Bartington’s portable apparatus for magnetic susceptibility probing along with the correlation of these results with the mineral composition obtained from X-ray diffraction tests. The analysed rock material was red and green clays from the vicinity of Czêstochowa, assigned to the mud-evaporite Ozimek Member, Grabowa Formation (Keuper facies, Upper Triassic). The obtained results indicate the possibility of a correlation between the MS and the composition of rock-forming minerals in the studied sediments, where in green clays the magnetite/maghemite with pyrrhotite(?) does not substantially affect the MS, and paraand/ or diamagnetic minerals have a decisive role. In the red clays the dominant MS carrier is the hematite.
A b s t r a c t. Measurements of the magnetic susceptibility (MS) in sedimentary sequences can quickly provide information on the variability of their mineral composition. A typical application of MS is the reconstruction of the supply of terrigenous material in carbonate rocks or the variability of the ratio of ferromagnetic to paramagnetic / diamagnetic minerals in clastic rocks. The article discusses the practical aspects of using the Bartington’s portable apparatus for magnetic susceptibility probing along with the correlation of these results with the mineral composition obtained from X-ray diffraction tests. The analysed rock material was red and green clays from the vicinity of Czêstochowa, assigned to the mud-evaporite Ozimek Member, Grabowa Formation (Keuper facies, Upper Triassic). The obtained results indicate the possibility of a correlation between the MS and the composition of rock-forming minerals in the studied sediments, where in green clays the magnetite/maghemite with pyrrhotite(?) does not substantially affect the MS, and paraand/ or diamagnetic minerals have a decisive role. In the red clays the dominant MS carrier is the hematite.