Folia Historico-Naturalia Musei Matraensis - A Mátra Múzeum Természetrajzi Közleményei 17. (1992)
Bužek, Č.–László, J.: Contribution to the Upper Pannonian flora from Visonta, northern Hungary
Fol. Hist.-nat Mus Matr., 17: 47-78, 1992 Contribution to the Upper Pannonian flora from Visonta, northern Hungary Cestmir BÚZEK - József LÁSZLÓ ABSTRACT:îhe first brown coal mine at Visonta in the southern piedmont area of the Mátra Mts. in NE Hungary, was opened in 1969. The mine yielded very interesting flora remains the leaf material of which was studied by I. PÄLFALVY and L. RÁKOSI (1979) while the leaf and fruit remains were described by 3. LÄSZL0* (1989a, b., 1991e, b). In this paper the authors givp the presentational discussion of seed and fruit remains. The development of the series with brown coal seams belonging to the Bükkalja Brown Coal Formation may be put into the Dacián and Roumanian periods of the (s.l.) Pannonian. Ouring the studies made on the seed and fruit remains numerous taxa had been recorded and determined which were not recognized in the leaf material because they were not fossilized. Thus we had a chance to make florlstic and environmental reconstruction of the flora of a Glyptostrobus swamp with considerably richer and more complex plant remains than before. The first large-scale open-cast brown-coal mine (Thorez mine) of the Mátra Piedmont area (N. Hungary) was opened in 1969 near Visonta (Fig. 1.). First paleobotanlcal collections at this locality were made in 1977. PÄLFALVY, I. and RÄK0SI, I. had studied the leaf material of these collections (1979). Till 1983, when the mine had been closed down continuous collections yielded very interesting flora remains the study of which has been already started by LÁSZLÓ, 3. (1989) and BÖZEK, С and LÁSZLÓ, 3. (in print). According to JÁMBOR, A. et al. (1988) the geological position of brown-coal bearing series at the southern Piedmont areas of the Mátra and Bükk Mountains within the (s.l.) Pannonian formation« in Hungary is the following: The formations summarized under the name BUkkalja Brown-Coal Formation are a part of the Heves Formation Group of the Transdanubian Main formation Group. They have been developed during the Dacián and Roumanian phases of the (s.l.) Pannonian. The results of geological researches and mining operations are summarized by RADÓCZ, Gy. (1985). Technological and geological investigations in the Thorez mine (Fig. 2.) demonstrated the presence of three, main brown-coal layers. In the geological profile made in 1979 (LA5ZLÓ, 3. 1989a) , already a divergence of the lowermost (III.) layer can be observed (Fig. 3.). Cleyey layers below the II. brown-coal layer yielded only leaf remains while the clayey layers above this brown-coal seam yielded macrofloral, palynofloral remains and also some fruits, seeds, needles and other remains of reproductive and vegetative organs. The remains were segregated from the emplis by washing and then cleared by HF (40 S) and HCL (30 4). After drying they were handpicked an separated under a binocular preparation microscope according to morphotypes. Their Identification is based on the morphological and anatomical comparison with fossil and recent material and respective literature. The material is Inventorized in the Paleobotanlcal collection of the Hungarian Geological Survey under Inv. Nos. BK.-5449 - BK.-5595. 47
