Paleozoik okolic Skalbmierza

Abstract

PALAEOZOIC IN THE REGION OF SKALBMIEBZ

The vicinities of Skalbmierz are situated within the eastern part of the Miechów trough (South Poland). The bore holes Skalbmierz 3 and 4, described in the paper, have for the first time encountered in this area the Palaeozoic deposits resting under the Tertiary, Cretaceous, Jurassic and Triassic formations. In the bore hole Skalbmierz 3 they have been pierced at the depth 1441,4-3042,8 m, and in the bore hole SkaIbmierz 4 at the depth 1114,7-1502,0 m.

The paper deals with the lithtoIogical development of the Palaeozoic deposits and the organic material that has been examined by means of maceration, thin sections, spore macerals and using microfaunistic analysis. A list of determinable and indeterminable organic fragments (Table 1) has been compared with the illustration of better preserved specimens. Palaeontological description, of the species Orbiculoidea tornacensis is given, as well. This species has not so far been encountered in the Carboniferous deposits of Poland.

In spite of an incompletely cored bore holes (Fig. 2) a fact has been ascertained that the Palaeozoic represants, in the bore hole Skalbmierz 3, the Lower Carboniferous (certain indicators down to the deth 1955,0). The presence of the Visean stage at an interval 1451,7-11841,4 m is proved by the foraminifers, ostracods·and brachiopods. On account of a lack of indicators showing the precence of the Upper Visean, we may speak about the Lower and Middle Visean only. At the depth 1953,0-1955,0 m the Tournaisian has been ascertained on the basis of brachiopod fauna and at the depth 2085,2-2662,7 m the deposits, of the Middle Devonian – Frasnian (?) have been encountered bearing coral fauna.

A lack of the arguments proving the age of the deposits occurring in various sectors did not allow to explain the problem of the Visean thickness and to establish the boundary Visean-Tournaisian, as well as the contact Carboniferous-Devonian. At the depth 3040,1-3040,7 m the Lower Devonian has been encountered. It is distinguished only solely by the analogy with the similar deposits found at Kazimierza Wielka bore hole Kazimierza Wielka 1 deepened at present). The Palaeozoic series pierced in the bore hole SkaIbmierz 4 belongs, as a whole, to the Middle Devonian-Frasnian (?).

It has been ascertained that in the vicinities of Skalbmierz a large Palaeozoic elevation occurs in the Mesozoic substratum. The elevation has been called Skalbmierz anticline (Fig. 3). The structure of the anticline is asymmetric, and the anticline itself is feebly recognized. Its NE fIank bore hole Skalbmierz 3) is built up of the Lower, Middle - Upper (?). Devonian and the bottom part of the Lower Carboniferous. In the SW flank the Upper Visean rests on the Lower and Middle Devonian (Słomniki 1).

According to the authors' opinion the area between Skalbmierz and Kazimierza Wielka constituted, at the Lower Carboniferous time, an elevation influencing the development of facial zones and the extents of the basins. The results obtained considerably change the opinions so far published. The present authors suppose that the elevation stretched at the Tournaisian and the Lower Visean times as far as the vicinities of Cracow, and joined the uplift of Puszcza, the sea invading its NE flank only. At the Upper Visean time the last area was being elevated and the areas stretching between Cracow, Skalbmierz and Puszcza were lowered and occupied by the transgressing sea. The continent of that period was an alimentation area for the conglomerates of the zone Słomniki - Łobzów. The continent constituted here a threshold connected, probably, with the prolongation of the Puszcza dislocation (Fig. 1).These phenomena depend upon the epeirogenic movements that have been responsible for the longitudinal and transversal dislocation, as well. These dislocations cut the Skalbmierz anticline in to several blocks displaced to each other.