VARIETIES OF SULFUR IN THE ALGINITE SEQUENCE OF KÖSSEN FACIES FROM THE BOREHOLE REZI RZT-1 (W-HUNGARY)

L. PÁPAY
Department of Mineralogy,
Geochemistry and Petrography
József Attila University
H-6701 Szeged, P.O. Box 651

During the Upper Triassic, in the western part of Hungary the paleogeographical conditions were favourable for the deposition of formations with high organic matter content. The best reference section of the Kössen Formation can be found in the Keszthely Mountains at Rezi Village: the borehole Rzt-1. The alginite sequence of the Kössen facies in the borehole Rzt-1 can be characterized by a moderate organic matter content (average Corg = 6.1 %), relatively high carbonate-rich mineral part (average Ccarb = 6.1 %) and relatively low total sulfur content (average Sat = 1.6 %). On the basis of comparison of the previous average values derived from the qualitative analysis of the alginite-bearing samples from the borehole Rzt-1 with others for other Hungarian and Slovakian alginites, it can be established that the carbonate carbon and total sulfur content is higher in the Rezi samples, than in the other Hungarian and Slovakian ones. Two changes can be observed in the distribution among the varieties of sulfur in the studied alginite samples from the borehole Rzt-1. Above the interval 181.9-199.6 m the following order: pyritic sulfur (Sap)   >   organic sulfur (Sat)   >   sulfate sulfur (SaSO4)  is characteristic. Between 199.6-233.3 m the order is Saorg   >   Sap sulfate sulfur (SaSO4)   >   and below 233.3 m repeatedly Sap   >   Saorg   >   SaSO4. According to the present and previous studies the alginite sequence of the Kössen facies may serve as a potential oil-source rock for petroleum found in the Zala basin. Presumably, the 20 %  of the sulfur content belonging to the Nagylengyel-type petroleum might have originated in the Kössen Formation.

Back