Szabó János szerk.: Fragmenta Mineralogica Et Palaentologica 21. 2003. (Budapest, 2003)

Comparing the two representative palaeocommunities, the following statements can be made. At Somlóvásárhely, JV. millecaput'is almost the unique Nummulites species (78 %), accompanied by only five, mosdy striate species. At Balinka, the dominance of N. millecaput h slightly higher (81 %), but eight different (punctuate, reticulate and striate) taxa are also present. Accordingly, the species spectrum of the community is wider and much more varied. The scarce presence of N. perforatus and N. brongniarti (2 % each) is noteworthy, because of the considerable size of the specimens. The generic picture of the communities is rather monotonous: they consist of four genera only. The eastward decrease of the dominant Nummulites (from 71 to 62 %) is an important feature, complemented by the increase of Discocyclina: 15 % at Somlóvásárhely and 36 % at Balinka. Assilina species are present up to 11 % in the Southwestern Bakony. The Operculina species are subordinate (2—3 %). Flgoire 5 — Geographic extension and stratigraphie position of the NummiiHtes communities of the Bartonian Nummulites mtZ/ecapuf Zone. Nummulites faibanii Zone (Figure 6) — In the Halimba and Balinka Basins, part of the Priabonian sediments has escaped erosion. That is why the representative section has been chosen from these areas. Core 552.2 m of borehole Sv. 1. is a tuffitic, sandy marl. Its Nummulites community is considerable (abundance index 3—4), but it is of low diversity. The subdominant species is the zone marker reticulate N. fabianii (42 %). It is closely followed by the striate N. incrassatus (AO %). The other species (JV. chavannesi, N. pulchellus, N. stellatus) combined constitute 15 %. Since also these are striate, this group became dominant (55 %). The generic composition is the following. There is absolute predominance of Nummulites (70 %), followed by Operculina (18 %) and discocyclinids (10 %). Scarce specimens of two more genera have also been found: communities Chapmanina and Gyroidina (1—1 % each). The other representative core is sandy limestone from the interval 368.1-375.4 m of borehole Balinka 219. Its Nummulites community is not very rich (abundance index = 3) and of low diversity. The main element is, also in this case, N. fabianii (49 %). The same percentage is reached by the three striate species combined: N. incrassatus (28 %), JV. chavannesi (14 %) and JV. pulchellus (9 %). A peculiar species of the community is JV. aff. preshvichianus, which is, however, very rare (1 %). Comparing the two communities, the following statements can be made. The species composition of the two communities is essentially identical. The difference mean only a single species: JV. stellatus is present in borehole Sv. 1., while JV. aff. preshinchianus in Ba. 219, respectively. The diversity is low, there are only five taxa present, and abundance is