Ksenolity z bazaltoidów z Rębiszowa koło Mirska (Dolny Śląsk)

Abstract

Xenoliths from basalts of Rębiszów near Mirsk (Lower Silesia, south Poland).S u m m a r y. The study presents results of research on basic extrusive rocks basaltoid from Rębiszów as well as xenoliths existing in these rocks. These xenoliths and the basaltoids were subjected to macro- and microscopic observations, as well as X-ray, chemical and differential thermal analyses. Xenoliths of various sizes, are thermally metamorphosed rock fragments, mainly of Izera granite- gneisses. Some of them are strongly altered. Products of their changes are: -tridymite, -cristobalite, goethite, lepidocrocite and others. Main component of that mineral mass is tridymite. The SiO2 polymorphic phases originated from reaction in high temperature, caused by basic magma (basaltic one), together with hydrothermal solutions and metasomatic processes on the detached xenoliths of the Izera granite-gneisses.