Acta Geologica 32. (1989)
1-2. szám - G. Császár: Transgressive Urgonian sequence with black "pebbles" from the Villány Mountains, Hungary
4 G. CSÁSZÁR Mountains and in the Királyerdő, here in several horizons (Dragastan et al., 1986). As to the considerations so far in the overlying strata of the formation of originally presumably also changing thickness (from several tens of meters to several hundreds of meters) silty marl is found with unconformity both in the Villány Mountains (Fülöp, J., 1966) and in the Királyerdő (Bleahu, M. et al., 1981): this is called Bisse Marl Formation in the Villány Mountains and Ecléja Marl Formation in the Királyerdő. The age of the former was put to Lower-Middle Albian, that of the latter to Upper Aptian. In harmony with the results of hydrocarbon exploration wells drilled in the Danube—Tisza Interfluve a gradual transition can be probabilized between the two formations. In the Villány Mountains of imbrication structure the Nagyharsány Limestone Formation is known only in the two outernmost imbrications, i.e. from that of Tenkes and of Villány (Fig. 2). The youngermost formation of the intermediate three imbrications is of Oxfordian age (Fülöp, J., 1966). The Cretaceous sequence of the two imbrications shows conspicuous differences. The Urgonian limestone with rudists and orbitolines in the Tenkes imbrication is 30 m thick and of Albian age is overlain with sharp boundary but with conformity by the Bisse Marl (Fülöp, J., 1966) while in the karstic cavities of the Barremian-Albian limestone of several hundred Fig. 1. Extension of Urgonian formations in the Villány zone. (Used maps: Fülöp, 3. and Dank, V., 1987; Bérczi-Makk, A., 1987). 1. Urgonian. limestone on the surface; 2. evidenced Urgonian limestone below the surface; 3. possible subsurface extension of the Urgonian limestone; 4. main tectonic lines