Horyzont podmenilitowych margli globigerynowych polskich Karpat zewnętrznych a zagadnienie granicy eocen-oligocen

Abstract

ON THE SUB-MENILLITE GLOBIGERINA MARLS HORIZON IN THE POLISH OUTER CARPATHIANS AND THE QUESTION OF THE EOCENE-OLIGOCENE BOUNDARY Summary Flysch rocks of the Polish Outer Carpathians display a few characteristic lithostratigraphic horizons, including that of so-called "Sub-menillite Globigerina Marls", closing Upper Cretaceous-Paleogene stage in evolution of the Flysch geosyncline. Biostratigraphic and geochronological studies showed that the Globigerina Marls originated at the turn of the Eocene and Oligocene. Within that horizon, it is possible to trace moments of appearance and disappearance of some foraminifer species (First Appearance Datum, FAO, and Last Appearance Datum, LAD). The moments, so-called "datum events", are discussed on the example of randomly selected section of the Sub- menillite Globigerina Marls at Skawinki SW of Cracow. The moments recorded here include : l) First Appearance Datum (FAD) of the species Turborotalia liverorskae (Bykova) , 2) FAD of the species Turharotafia increbescens (Bandy). 3 ) FAD of the species Globigerina ampliapertura Bolli, 4) FAD of the species Turborotalia permicra Blow et Banner, 5) Last Appearance Daturn (LAD) ofthe species Turborotalia increbescens (Bandy), 6) F AD ofthe species Turborotalia brevispira (Subbotina), 7) LAD of the species Acarinina rugosoaculeata Subbotina, 8) FAD of the species Globigerina tapuriensis Blow et Banner, 9) FAD of the species Globigerina brevis Jenkins, and 10) LAD of the species Globigerina eocaena Guembel. The phenomena recorded here are analogous as those found in foraminifer faunas in epicontinental and oceanic deposits from the turn of the Eocene and Oligocene in several other areas. Taking this into account it is suggested that the Sub-menillite Globigerina Marls of the Polish Outer Carpathians should be covered by works tarried out within the frame of the IGCP Project no. 174, Eocene-Oligocene boundary events, and IUGS Working Group on the Eocene-Oligocene boundary.