Stratygrafia górnego triasu NE części obrzeżenia Górnośląskiego Zagłębia Węglowego

Abstract

STRATIGRAPHY OF THE UPPER TRIASSIC IN THE NE MARGIN OF THE UPPER SILESIAN COAL BASIN SummaryThe results of lithological-sedimentary studies and palynological analyses allowed the authors to present sedimentary succession, to make stratigraphical subdivision and to detect gaps in the vertical geological section of the Upper Triassic within the north-eastern margin of the Upper Silesian Coal Basin.The oldest member of the Upper Triassic, distinguished on lithological and palynological criteria, is represented by the Lower Gypsum Keuper with the equivalent of the Grenzdolomit.The spore-and-pollen assemblage is represented mainly by numerous species of the genus Ovalipollis K r u t z s c h, among them O. ovalis K r u t z s c h, O. breviformis K r u t z s c h, O. lunzensis K 1 a u s, and of the genus Triadispora K 1 a u s particularly the species T. undulata O r ł and T. keuperiana O r ł, as well as the species Conbaculatisparites longdonensis C l a r k e, Camerosporites secatus L e s c h., Duplicisporites granulatus L e s c h. and others, (Fig. 3). It has been ascertained that on the deposits of the Lower Gypsum Keuper or, in some sections, on the deposits of the Muschelkalk (Fig. 2) the successive stratighraphic member, i.e. the reed sandstone (Schilfslandstein) occurs. The overlapping reed sandstone is characterized by the presence at a specific facial-sedimentary type of the deposits, and of the index spore-and-pollen assemblage, in which, beside the fo the genus Ovalipollis K r u t z s c h are found spores of the species Aulisporites astigmosus (L e s c h.) K l a u s. Numerous are also spores of the genus Aratrisporites. Moreover, there are observed characteristic species like Camarozonosporites (C.) rudis (L e s c h.) K l a u s~ and Camarozonosporites (C.) laevigatus S c h u l z. The hiatus comprises deposits of the Upper Gypsum Keuper. Higher up there occur Rhaetian deposits laid down on the reed sandstone deposits or on the Muschelkalk ones. Both lithological and sedimentary features of these deposits allow to ascertain that the area under consideration distinguishes itself by a whole sedimentary succession of two large cyclothems R I and R II.In the Rhaetian deposits, mainly in the cyclothem R II, a spore-and-pollen assemblage appears, where the following species predominate: Granuloperculatipollis rudis V e n k.·et G o c·z a n, Corrollina meyeriana (K 1 a u s) V e n. k.et G o c z a n, Classopollis classoides (P f.) P o c. et J a n s., Enzonalasporites marginalis (L e s c h.) S c h u l z, E. manifestus L e s c h., E. vigens L e s·c h., Brachysaccus cf. B. neomundanus (L e s c h.) M ¬ d l e r, Cedripites microreticulatus O r ł. and others (Fig. 3). This assemblage may be correlated with that of the Jarkowo and Zbąszynek Beds in the sections of West Poland.