Tufity mioceńskie z obszaru Gliwic

Abstract

MIOCENE TUFFITES FROM THE AREA OF GLIWICE

Summary

Two horizons of tuffites have been found to occur at depths of 104 m and 195 m in the Miocene deposits of mine Gliwice. The tuffites have been examined petrographically. The upper horizon (T₁) is built of vitro clastic tuffites, chemically resembling rhyolite lava. Pyroclastic material is preserved fresh in it. The tuffites of the lower horizon (T2) are montmorillonitized. The presence of phenocrysts, beside the glass here, suggests that these latter are vitroclastic tuffites. Chemical examinations demonstrate that these were previously of dacite character. Various preservation state of the tuffites in study has been conditioned by the specific system of the Miocene hydrogeological formations. The tuffogene horizons found in the Miocene deposits of the GIiwice mine prove that the range of the pyroclastic deposits within the Upper Silesian area is somewhat greater than so far supposed.