Dolny karbon w Jaroszowcu koło Olkusza

Abstract

LOWER CARBONIFEROUS AT JAROSZOWIEC, NEAR OLKUSZSummaryLower- Carboniferous clay-sandy deposits (Fig. 2) have been found to occur under the dolomitic formations of Roethian age, as shown by bore hole Jaroszowiec BJ-46, situated in the Olkusz region (Fig. 1). On the·basis of lithological features the section of these deposits may be subdivided into three parts. Both the lower and upper parts of the section are characterized by the predominance of siltstones, whereas in the middle part claystones prevail. The Lower Carboniferous deposits are dark-grey and grey in colour, except for the top portion of the section, where they are variegated. Along the entire section, the dip of strata ranges from 20 to 30°.Index forms like Posidonia becheri B r n n. and (?)Goniatites crenistria intermedius K o b o l d (Table 1 and Plate I) allow the deposits in study to be referred to the Upper Visean. It should be emphasized here that the form (?) Goniatites crenistria itntermedius more precisely determines the age of the deposits considered, which may correspond to the subzone Goa4, i.e. to the lower part of the Upper Visean.Floristic (Table 2) and microfloristic (Table 3) studies do not exclude – in the case of flora – but confirm – in the case of microflora – the Upper Visean age of the deposits considered.On lithologic-palaeontolgical evidences the Lower Carboiniferous deposits have been compared with those of the IV sedimentary zone Wieliczka-Woźniki (K. Bojkowski and S. Bukowy, 1966). Their similarity to the deposits of the II facial zone (S. Bukowy, 1964) allowed the author to refer them to the Słomniki syncline.