Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 16. 1993. (Budapest, 1993)

Bánat Region Bánat region is close to the southeastern border zone of the Great Hungarian Plain. Basalts in this volcanic region seem to be older (11 m.y.). Two occurrences of basalt lava flow have been analysed here (analyses 251-252). Lucaret = Lukácskő (LUC) lava is a mildly undersaturated basanite (ne 7.7%, mg 63.7), while the rock of Sanovita = Sziklás (SAN) is even less undersaturated (ne 0.6%, mg 64.8). The enrichment of LREE and incompatible elements is characteristic of alkali basalts and basanites (Table 2, 3). Similarly to Nógrád and Graz Basin basalts, Sr isotope ratio is low and that of Nd is high (Table 4). Persányi Mts. Basalt volcanoes of the Persányi Mts. are situated in a highly special tectonic environment at the eastern border zone of the Transylvanian Basin, close to the bend of the Carpathian arc. Several young alkali basalt volcanoes are known in this region ranging in age from 0.71 to 2.25 m. y. Rákos (RAK) is a moderately undersaturated primitive basanite (Table 1, analyses 244-245, mg 72.2, ne 6.3, S.I 8.12). The enrichment in incompatible elements is relatively low (Table 2). It is characterised by a very low Ce/Pb ratio and a negative Nb anomaly. The Sr isotope ratio is fairly high, Nd isotope ratio low (Table 4). This basalt plot at the high 207pb/204ph side of the NHRL of HART. All this features point to a high proportion of a subduction related lithospheric component in the liquid. Basalts of Comana de Sus = (Felsőkomana) (COM), Bare = Sáromberke (BAR), Sarata (SAR), Bogata (BOG) are similar to Rákos, but no Nb anomaly can be observed. ACKNOWLEDGEMENTS This work has been financially supported by the OTKA Grant No. 2026 (A EMBEY-ISZTIN and G. DOBOSI). REFERENCES BALOGH, K. (1984): A K/Ar földtani kormeghatározási módszer hazai bevezetése és alkalmazásának eredményei. - C. Sc. Thesis, Debrecen, 104 pp. EMBEY-ISZTIN, A. & SCHARBERT H. G. (1981): Bericht über geokemisch-petrologische Untersuchungen an Basalten vom Kovácsi-hegy und Uzsabánya (Tátika Gruppe, Ungarn). - Anzeiger d. math.-naturw. Klasse d. Österreichischen Akad. d. Wissenschaften, 5: 67-72. EMBEY-ISZTIN, A, SCHARBERT, H., DIETRICH, H. & POULTIDIS, CH. (1990): Mafic granulites and pyroxenite xenoliths from the Transdanubian Volcanic Region (Hungary): implications for the deep structure of the Pannonian Basin. - Mineralogical Magazine, 54: 463-483. EMBEY-ISZTIN, A, DOWNES, H., JAMES, D. E., UPTON, B. G. J., DOBOSI, G., INGRAM, G. A, HARMON, S. R. & SCHARBERT, H. G. (1993): The petrogenesis of Pliocene alkaline volcanic rocks from the Pannonian Basin, Eastern Central Europe. - Journal of Petrology, 34: 317-343.