O wieku cieszynitów na podstawie analiz minerałów ciężkich w górnych łupkach cieszyńskich

Abstract

AGE OF TESCHENITES ON THE BASIS OF AN ANALYSIS OF THEIR HEAVY MINERALS FROM THE UPPER TESCHEN SHALESWhile examining associations of heavy minerals from the Upper Teschen beds I observed pyroxenes and amphiboles derived from teschenites. The examined material was collected at Rudowo, about 4 km. NNE from Cieszyn. These sampIes are from silty and clayey Upper Teschen shales, and from the contact of these shales with teschenites.In their majority, the samples contain opaque minerals. I have distinguished the following minerals: zircon, rutile, brookite, anatase, augite, diopside, tourmaline, garnet and baryte. The percentage of mineral content varies and depends on the location where the sample had been taken ion relation with the contact. The greater distance of that location from a contact, the higher proved to be the content and the variety of transparent minerals. Thus, the amount of zircon and rutile increases with growing distance from a contact. Brookite, tourmaline and garnet; occur exclusively in a sample of unaltered calciferous silstone. It seems probable that these minerals were instable in conditions of a contact metamorphosis, or that, in stratigraphicaly higher horizons, changes took place in the composition of the associations of heavy minerals.