The geochemical facies of Hungarian thermal waters were the object of this study. Samples were separated into groups by relative ages (δ18O values). Mature and immature subgroups were formed on the basis of dissolved (semi)volatile organic compounds. The oldest (connate) waters form one group with a small number of samples. The subgroups containing different small molecular-sized soluble aromatics differ sharply in their chemical features (sodium, hydrogen carbonate, iodine, ammonium etc. content). The origin of the organic matter may differ in the subgroups as inferred by their different δ18O values and ten times greater halogen contents.
Our results show that the decomposition of organic matter produces small molecular-sized aromatic compounds and also influences the amounts of inorganic components in thermal waters, through the increase of feldspar hydrolysis and carbonate dissolution.
Deák, J. 1995: A felszín alatti vizek utánpótlódásának meghatározása izotópos módszerekkel az Alföldön (Determination of recharge of groundwater on the Great Hungarian Plain by isotope techniques). — VITUKI Zárójelentés, pp. 28. (In Hungarian.).
R. Fuge C. Johnson 1986 The geochemistry of iodine — a review Environmental Geochemistry and Health 8/ 2 31 35.
Kárpáti, Z., Cs. Sajgó, I. Vető, G. Klopp, I. Horváth 1995: Identification of various organics in thermal waters in the Pannonian Basin. Preliminary reports. — In: Grimalt, J.O., C. Dorronsoro (eds): Organic Geochemistry Developments and applications to energy, climate, environment and human history. A. I. G.O. A. Donostia-San Sebastian, pp. 594–596.
Z. Kárpáti I. Vető Cs. Sajgó 1996 Organic microcomponent composition of thermal waters in Hungary Egészségtudomány 60/ 4 356 364.
Kárpáti, Z., I. Vető, Cs. Sajgó 1996b: A hazai termálvizek szerves mikrokomponens vizsgálatainak újabb eredményei (New results on organic micro-components of Hungarian thermal waters)? — In: Dudinszky L.-né (ed.) A víz és a vÍzi környezetvédelem a Kárpát-medencében. — Magyar Hidrológiai Társaság, pp. 811–843. (In Hungarian.).
Z. Kárpáti Cs. Sajgó I. Vető G. Klopp I. Horváth 1999 Organic matter in thermal waters of the Pannonian Basin — A preliminary report on aromatic compounds Organic Geochemistry 30 701 712.
M. Stute J. Deák 1989 Environmental isotope study (14C, 13C, 18O, D, noble gases) on deep groundwater circulation systems in Hungary with reference to paleoclimate Radiocarbon 31/ 3 902 918.
J. Tóth I. Almási 2001 Interpretation of observed fluid potential patterns in a deep sedimentary basin under tectonic compression: Hungarian Great Plain, Pannonian Basin Geofluids 1 11 36.
I. Varsányi L. Ó. Kovács Z. Kárpáti J.M. Matray 2002 Carbon forms in formation waters from the Pannonian Basin, Hungary Chemical Geology 189/ 3–4 165 182.
I. Varsányi L. Ó. Kovács 2009 Origin, chemical and isotopic evolution of formation water in geopressured zones in the Pannonian Basin, Hungary Chemical Geology 264 187 196.
I. Vető I. Futó I. Horváth Zs. Szántó 2004 Late and deep fermentative methanogenesis as reflected in the H-C-O-S isotopy of the methane-water system in deep aquifers of the Pannonian Basin (SE Hungary) Organic Geochemistry 35/ 6 713 723.
I. Vető I. Horváth Gy. Tóth 2004 Outlines of the geochemistry of Hungarian Thermal Waters Hungarian Journal of Chemistry 109–110 199 203.