Mineralizacja wapieni triasowych w Zawadzie (Górny Śląsk) i jej związek z utworami liasu

Abstract

MINERALIZATION OF TRIASSIC LIMESTONES AT ZAWADA (UPPER SILESIA) AND ITS CONNECTION WITH LIAS DEPOSITS

In the region of Mierzęcice (northern part of Upper Silesian Coal Basin), in limestones of the MiddIe Triassic, there have been identified symptoms of mineralization by a ferruginous substance. In an outcrop at Zawada (south of Mierzęcice, Fig. 1) there may be observed the Upper Gogolin beds of a conglomeratic series and the horizon of Wellenkalk II. In the directly superimposed strata there lie ferruginous sandstones with muscovite, and sands representing the Lower Lias (Fig. 2).

In order to characterize this mineralization, the author undertook a number of chemical analyses which have been presented on Table 1; from this table it appears that the highest accumulation of ferruginous material Fe₂O₃ exists in the lower part of horizon Wellenkalk II (Fig. 2, bed B). Proceeding in this horizon along the boundary between the Wellenkalk and the limestones of the conglomeratic series (Fig. 2, bed B) we find, in closest vicinity to limestones disclosing an increase of Fe₂O₃ content, light-grey Wellenkalk layers in which there is but an insignificant content of iron. This fact indicates the epigenetic character of mineralization of the Triassic limestones by a ferruginous substance.