Wkładki gnejsowo-łupkowe oraz inne skały żyłowe w obrębie wychodni leukogranitów w Kopańcu (Góry Izerskie)

Abstract

GNEISS-SCHIST INTERCALATIONS AND OTHER VEIN ROCKS WITHIN LEUCOGRANITE OUTCROPS AT KOPANIEC (IZERA MTS.)SummaryThe article presents new opinions on intercalations in leucogranites. All schliers and enclaves differing in their petrographic character from leucogranites, were thought by J. Oberc (1967) to be older than leucogranites, and to represent, in relation to these latter, the so-called “skeleton structures”. Basing on rich analytical materials, the present author states somewhat different opinion. The differences concern nomenclature, genetical nature of intercalations, their age relations to leucogranites, and character of, contacts with the adjacent rocks.The following are rocks discussed in the article: schliers of gneissose granites and of gneisses, series of quartz-micaceous schists, amphibolite schists and amphibolites, enclaves of greisen type, veins of quartz pegmatites, injections of vein quartz, series of flogopite-apatite rock and lamprophyre veins (spessartite and microdiorite). These rocks originated due to numerous rocks-forming processes of various age and different provenance. Series of quartz-micaceous schists, amphibolite schists and amphibolites, as well as schliers of gneissose granites and of gneisses, representing relics of granitoid rocks preserved from leucocratization, are referred to the rocks older than leucogranites (Fig. 1). They were formed during the processes of regional metamorphism.Of the same age, or somewhat younger than leucogranites, are greisen schliers and numerous veins of quartz injections that fill in at places the interspaces in leucogranites and in schists. Moreover, the area under study is characterized by numerous traces of Variscan magmatic processes connected with the Karkonosze granite intrusion. Rocks produced at that period are distinctly younger than leucogranites. The present author refers here pegmatite (quartz-feldspar-biotite) veins, biotite series and quartz veins, as well as a series of flogopite-apatite rocks and lamprophyre veins. All younger veins, except for flogopite-apatite one, fill in the fracture system running obliquely to the main trend of foliation and gneissic structure of the Izera series.