Wstępna charakterystyka petrograficzna anhydrytów Werra monokliny przedsudeckiej

Abstract

PRELIMINARY PETROGRAPHIC DESCRIPTION OF TOE WERRA ANHYDRITES FROM THE FORE-SUDETIC MONOCLINESummaryThe Werra anhydrite series found to occur in the region of Lubin and Sieroszowice (Fig. 1) may be subdivided into 4 petrographically different horizons (Figs. 2–4): horizon of packet anhydrites, horizon of medium-crystalline and coarse-crystalline anhydrites, horizon of aphanite anhydrites, and sulphate-carbonate horizon.These horizons differ from each other first of all in having other textures and structures, partly also other mineralogical composition (Table I, Figs. 6–9). Their differences are distinctly visible also in the size of crystals within the individual horizons (Fig. 5).Microscope examinations point to the hydratization process of anhydrite, and to the dehydratization process of gypsum. Two generations of gypsum crystals are visible, too. The younger generation is an effect of anhydrite hydratization. This phenomenon, observed to occur at the horizon of packet anhydrites, is responsible for the specific texture and structure of this rock. Both textures and structures of the rocks of the other horizons are, most probably, of sedimentary character.Microscope examination also demonstrate that in marine water mainly gypsum had precipitated, which in later period passed into anhydrite.