L. Hably szerk.: Studia Botanica Hungarica 22. 1990 (Budapest, 1990)
The layers comprising Pectunculus are situated within this unit. At some places, there are micaceous seams of clay. Unit 'C is replaced by unit 'D', lasting till the end of the trench, extending over approx. 112 m. It is comprising a loose, rough grained sandstone with occasional intercalations of clay lenses. After the first 17 metres of unit 'D' we find a rich Molluscan fauna. A fault line is situated here, on the northern part of which we find the Molluscan layers, while on the southern parts the layers with coal seams can be spotted. The angle of dip of the fault line is 310/20 . Considering the dip and the direction of the layer with coal seams, it can be identified with the beds containing the plant remains. The Molluscan fauna was determined by BÁLDI (1976). The fauna is dominated by Upper Oligocène species, including species encountered in the Lower Oligocène and the Miocene as well. The species Ampullina crassatina Lamarck and Globularia sp. became extinct by the end of the Oligocène, thus we cannot deal with a Miocene sequence here. On the other hand, the species Oivalinga ornata Agassiz appears first in the Upper Oligocène, thu,s excluding the Lower Oligocène age. The nannoplankton studies on the layer containing the leafprints revealed that the bed in question belongs to zone NP 24-25 (p.c. of A. NAGYMAROSY), i.e. the Egerian stage. Taking into consideration the single uncertain specimen of Coccolithus orangensis Bukry , the age of the sample can be restricted to zone NP 25, that is, the end of the Oligocène. The nannoplankton flora, however, is extremely poor, characterized by small individual number and small diversity. The nannoplankton assemblage determined denote an euhaline sea water, which is not saying that our layers were necessarily deposited in euhaline waters, because the nannoflora could have been drifted there by single wavedrifts as well. The Molluscan remains denote uneven, changing salinity, anyways, surpassing 10%o. The presence of Tympanotonus and Ampullina denote near-shore or lagoon facies. Lithological remains as well as the macroflora denote the same environmental conditions. The Upper Oligocène flora of Vértesszőlős used to live, seemingly, along the sea-shore. THE MATERIAL ELABORATED AND METHODS OF INVESTIGATION The palaeobotanical remains, mainly leaf prints, were preserved in argillaceous sandstone. The platy layers with muscovite denote an undisturbed sedimentation, supported by the leafprints found in good state of preservation. The surface of the bedding planes are crowded with leafprints, many times making the determination and recognition of the remains difficult. In most cases, only the prints of the leaves were preserved, though in some cases remains of the epidermis can be spotted in small patches, oxidized and fragmented. The rock itself was saturated with ferreous solutions. Most of the prints can be characterized by the same rusty colour. The state of preservation of the finds depends considerably on the rock containing more sandy or clayey particles. As in our case most of the finds were preserved in sandstone, mainly the margin of the leaves and the teeth are injured, sometimes the complete margin is missing. The rock samples containing leaf prints encountered in the public collections contain, in most cases, several leafprints, thus the inventory number of different species described from the same hand specimen can be identical. Thus the sum of the inventory numbers does not equal with those of the individual remains. Therefore, when listing the inventory number, the number of prints of a given species is also marked. Thus different species can have equal inventory number as well. The inventory number consists of three parts. The first part is the same in case of all remains, i.e., 76, which stands for the year of inventorization . The next number is the serial number itself, while the third number denoted if the piece consists of one rock piece only or if it has a counterpart. In this case, the last figure of the inventory number is 2. Thus on the 337 inventory items there were nearly 600 leafprints determined, as well as several indetermined pieces and log fragments visible. 5
