Profil i mikrofauna najwyższej części warstw krośnieńskich w Kluczowej koło Jasła

Abstract

PROFILE AND MICROFAUNA OF THE UPPERMOST PART OF THE KROSNO BEDS AT KLUCZOWA, NEAR JASŁO Summary The authors give a detailed lithological description of the Krosno beds building up the northern limb of the Podzamcze fold and particularly stress their uppermost part, which occurs in a contact with the formations of the Magura sheet of Kluczowa. In this profile the uppermost part of the Krosno beds is developed in the shaly facies. Near the contact with the nappe, there occur in these shales numerous pebbles of shales and of Magura sandstones, proving the erosion of the front of the Magura nappe during the final period of sedimentation of the Krosno beds in this area. The collected samples from the Krosno beds near the contact area with the Kluczowa sheet contain rich microfauna, particularly planctonic one. On this basis the age of the uppermost part of the Krosno beds was determined to be the Oligocene. Two assemblages of microfauna were distinguished there: an assemblage with the Oligocene microfauna and another one with an admixture of the upper Eocene microfauna. As a result of the investigation, an assumption was made that the microfauna of the second assemblage was carried down, together with clayey-marly mud and pebbles of grey shales, from the southern sublittoral zone into the deeper parts of the Silesian basin.