Bazické magmatity v okolí Janova ve Slezsku

Abstract

This study deals with petrographic description of Variscan magmatic rocks in Andělská Hora Formation in vicinity of Janov in Silesia. In accord with published information, it is possible to distinguish three groups of volcanics and associated volcanoclastic rocks in this geologically complicated area. These groups are so-called „Janov basites“ (in Czech janovská basika), greenschists from Pokrzywna and diabases from Jindřichov. Samples of these rocks were studied using electron microprobe and also there were used results of radioisotopic dating and chemical analyses. Based on the work performed, „Janov basites“ should be considered as posttectonic intrusions of the character of lamprophyres which cannot be associated with other two groups representing Early Carboniferous volcanism probably related to the continuation of the Šternberk-Horní Benešov Belt.