Związek utworów podłoża obszaru Cieszyn–Rzeszotary ze skałami krystalicznymi wyspy Goryczkowej Tatr

Abstract

RELATIONSHIP OF THE METAMORPHIC BASEMENT FORMATIONS IN THE CIESZYN-RZESZOTARY AREA AND THE CRYSTALLINE ROCKS OF GORYCZKOWA ISLAND IN THE TATRA MTS.SummaryIn an article published in 1971 the present authors tried to demonstrate a relationship of the metamorphic formations found in the Cieszyn-Rzeszotary area and the Precambrian formations within the Carpathian foreland. New data, obtained in the recent time, encourage to look for some relationships with the crystalline rocks of the Goryczkowa Island in the Tatra Mts. (Fig. 1), recently worked out by J. Burchart (1970).Detailed petrographic examinations have demonstrated that apart from a, marked differentiation the metamorphic formations found in the Cieszyn-Rzeszotary area and in the Goryczowa Island of theTatra Mts. show a lot of common features as follows: approximate mineral composition, similar character of alterations, and numerous mineral relics represented here by quartz garnet, apatite and zircon. The results of calculating mineral composition of all the rocks considered are shown in a projection triangle (Fig. 2). There is given also the percentage content of some minerals in the rocks under examination (Fig. 3).All gathered data show that all these rocks have been formed as a result of the metamorphisation of a primarily very differentiated complex of sedimentary rocks. This metamorphism was of regional  character. In its first phase the metamorphism was of isochemical nature (e.g. in the crystalline schists pierced in boreholes Puńców 1 land Bielsko 5), and only in a later period allochemical alterations took place on a large scale. The alteration of the primary rocks resulted in a change of their appearance and mineral composition that resemble those of the granitoids found by boreholes Kęty 7, 8 and 9 (W. Heflik, K.Kanior, 1970). Both the development and the alteration phases of the crystalline rocks from basement of the Ciszyn-Rzeszotary area resemble the development and formation conditions of the crystalline rocks found to occur in some regions of the Tatra Mts. It appears, therefore, that the Tatra crystalline basement and the rocks of the Sub-Devonian basement of the Cieszyn-Rzeszotary area are genetically connected with each other, and that each type occurring in them is related to another front of the moving waves of metamorphism. In both elements there are found several different genetic types. If at a given site – according to J. Burchart (1970) – “only one genetical type of granitoid is accessible, the problem can be explained by a fact that the other members of the series underwent destruction or are hidden at greather depths”, and have not so far been encountered in the Cieszyn-Rzeszotary area by drillings.