Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 83. (Budapest 1991)

Kvaček, Z. ; Hably, L.: Notes on the Egerian stratotype flora at Eger (Wind Brickyard), Hungary, Upper Oligocene

ped in marine faciès, which upwards gradually merging into near-shore, brackish and limnic environment. The Eger Formation of the Egerian age rests conformably without any break of sedimentation on the Kiscell Clay (Early Oligocène) as shown by a core made in the pit. Four members of the Eger Formation has been recognized at EW: 1 - Marine Glauconitic and Tuffitic Sandstone (without macroflora), 2 - Molluscan Clay (with rich deep littoral to bathyal fauna), 3 - Alternating Clays and Sandstones (With shallow marine fauna) and 4 - Coarse Sand with Intercalating Clays and Gravels (of brackish and limnic origin). All the units are exposed at present in the clay pit. Three levels of the macroflora occur in the section. The lower level flora (EWL) is situated in the upper part of unit 2 and includes the lower and higher horizons marked by LEGÁNYI as x 2 and x 1. The middle level flora (EWM) is connected with the middle part of unit 3 and also forms several thin horizons. The upper level flora (EWU) is bound to sandy clays of unit 4. The thickness of the members differs today from those given by BÁLDI (1973) due to progressed excavations. EWU and EWM come closer together. The plant remains in EWL are carbonized and occurred obviously sparsely so that only the long-term activities of F. LEGÁNYI could result in well-represented gatherings. Most of the plant fossils come from EWU, where thicker leaf beds packed with impressions occurred. At present this horizon is exhausted and not well accessible. We have found best opportunity to collect isolated leaf impressions mainly in EWM. The stratigraphical position of EWL and EWM is fixed by planktonic index fossils. Contrary to the original interpretation (in BÁLDI & SENES 1975) it has become clear that only the lower part of the Egerian is exposed at EW. According to A NAGYMAROSY (letter of 13. 1. 1989): "the profile covers the lower part of the stage (Egerian), i.e. the foraminifera zone G. opima opima and the nannoplankton zones NP 24 (upper part) - NP 25 zone (lower part). Near this locality (EW) is the stratotype (parastratotype) Novaj-Nyárjas, where the zones NP 24 and NP 25 were proved. Unfortunately Mrs. BÁLDI some years ago has misdetermined a fossil from this section (Sphenolithus belemnos, NN 1) and she published it. Her new revision (and also my revision) proved that the fossil is not S. belemnos so this very young age is not valid in that profile." We cannot expect a long-time gap between EWM and EWU and thus the whole flora reflects conditions of deeper parts of the Egarian only. The situation in the clay pit is shown in the Fig. 1. The outline in broken line shows the profile in the 1960s (according to BÁLDI 1966), the full line indicates the present state of 1990. Fig. 1. Geological profile at the Wind's brickyard with the levels of macroflora (broken line - after BÁLDI 1966, full line - actual situation in 1990), 1 = Glauconitic sand, 2 = clays, 3 = sand