Mineralizacja kruszcowa wschodniej strefy kontaktowej granitu karkonoskiego na obszarze Mniszkowa - Rędzin

Abstract

Omówiono grejzeny występujące we wschodniej osłonie Karkonoszy. Na podstawie przeprowadzonych badań zaliczono je do kwarcolitów. Opisano nowe wystąpienia mineralizacji kruszcowej w Mniszkowie i Rędzinach, stwierdzając że jest ona pochodzenia hydrotermalnego.ORE MINERALIZATION AT EASTERN CONTACT ZONE OF THE KARKONOSZE GRANITE IN THE MNISZKÓW -RĘDZINY AREA In the years 1978 - 1980 the authors carried out geological mapping of the contact zone of the Karkonosze granite and its metamorphic cover rocks in area between Mniszków and Rędziny (Fig. 1). A special attention was paid to rocks hitherto treated as greisens. The results of field works and microscopic analyses show that they mainly represent quartzolites formed in strongly fractured rock massif. They are mainly built of quartz, sericite, muscovite, and K-feldspars, whereas accessory minerals include hematite, laucoxene, and zircon. There has been found a new locality of polymetallic ore mineralization. Twenty ore minerals formed due to activity of hydrotherms are reported. The ore mineralization has been accompanied by formation of quartz, the major product of hydrotherms. Results of electron microscope analyses include the record of cassiterite in materia1 from the area of an old quarry at Ręziny, and admixture of Sn in futile. The Sn mineralization is assigned to the third stage in the K. Mochnacka (1982) classification. Replacement of hydrothermal ore minerals by hypergenic ones is omnipresent. The described mineral assemblage does not differ in composition from mineral associations of the known deposits in eastern cover of the Karkonosze granite (Miedzianka, Czarnów). Ore minerals formed due to regional and contact metamorphism are common in metamorphic rocks (hornfelses, micaceous schists, and amphibolites).