Konkrecie barytowe w iłach serii poznańskiej ze Stabłowic pod Wrocławiem

Abstract

BARYTE CONCRETIONS IN THE POZNAŃ SERIES CLAYS AT STABŁOWICE NEAR WROCŁAW

Summary

Baryte concretions have been found to occur in the Pliocene cays of the Poznań series at Stabłowice (Tabl. I, Fig. 4). The clays consist mainly of beideillite, partly also of illite, kaolinite, quartz and calcite (Figs 1, 2). In addition to, the barite concretions there occur here later carbonate ones (Fig. 1 c). The fine-grained mass of the baryte concretions reveals numerous voids filled in with growing barite crystals up to 4 mm in height (Tabl. I, Fig. 5).
Optical, X-ray (Fig. 3) and chemical (Tabs 1, 2) examinations have practically demonstrated a monomineral composition of the baxyte concretions (approximately 96% BaSO₄). Baryte found in the concretions under examination is characterized by a low content Sr, ascertained in barytes of similar hypergene origin. The barite concretions have been formed – according to the present authors – by a selective diagenetic differentiation of chemical elements, which took part within the clay series.