Nowe stanowisko fauny numulitowej serii podśląskiej w Porębie k. Myślenic

Abstract

Opisano nowe stanowisko z bogatą fauną paleogeńskich dużych otwornic z Poręby k. Myślenie, ok. 30 km na południe od Krakowa. Duże otwornice, głównie dyskocykliny i numulity, pochodzą ze żwirowca mulastego znajdującego się w pozycji łupków menilitowych osadów fliszowych jednostki pod śląskiej.A NEW LOCALITY OF NUMMULlTES FAUNA IN THE SUBSILESIAN NAPPE AT PORĘBA NEAR MYŚLENICE The described locality of larger foraminifers is situated at the bank of the Trzemeśnianka Creek at Poręba. In that locality, strata of the Subsilesian nappe crop out form beneath those of the Silesian nappe, in a tectonic window in the foreland of the Magura nappe. The Subsilesian nappe is here represented by gray shales (Middle·- Upper Eocene), underlain by gray shales with gypsum (Paleocene - Lower Eocene), shales with glauconitic sandstones (Paleocene - Lower Eocene) and light-green shales (Paleocene - Lower Eocene). The strata are discordantly overlain by paddly mudstone, dated at the Lower-Middle Eocene on the basis of microfauna found in randomly taken samples. The paddly mud stone is black at the top and brownish at the base and characterized by mass occurrences of tests of larger foraminifers, quartz grains, siderites and fragments of sandstones. The black mudstone passes upwards into gray shales with spherosiderites, and the brownish is underlain by medium-grained conglomerate, built of quartz, phyllitic shales. fragments marts, and larger foraminifers. The above described strata are not similar to typical hierogyhp beds nor menillite shales. The paddly mudstone from Poręba is here treated as an equivalent of menillite shales as the neighboring, more complete section of the latter also displays paddly mud stones with rich fauna of larger foraminifers. Incomplete development of the strata in the studied section may be explained as due to tectonic activity.and some disturbances in sedimentation.