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

During the Upper Triassic, in the western part of Hungary the paleogeo graphical conditions were favourable for the deposition of formations with high organic matter content. The best reference section of the Ko ssen Formation can be found in the Keszthely Mountains at Rezi Village : the borehole Rzt-1. The alginite sequence of the Kossen facies in he borehole Rzt-1 can De characterized by a moderate organic matter cont ent (average C-org = 6.1%), relatively high carbonate-rich mineral par t (average C-carb = 6.1% and relatively low total sulphur content (ave rage S-t(a) = 1.6 %. On the basis of comparison of the previous averag e values derived from the qualitative analysis of the alginite-bearing samples from the borehole Rzt-1 with others for other Hungarian and S lovakian alginites, it can be established that the carbonate carbon an d total sulphur content is higher in the Rezi samples, than in the oth er Hungarian and Slovakian ones. Two changes can be observed in the di stribution among the varieties of sulphur in the studied alginite samp les from the borehole Rzt-1. Above the interval 181.9-199.6 m the foll owing order: pyritic sulphur (S-p(a)) > organic sulphur (S-org(a)) > s ulphate sulphur (S-SO4(a)) is characteristic. Between 199.6-233.3 m th e order is S-org(a) > S-p(a) > S-SO4(a) and below 233.3 m repeatedly S -p(a) > S-org(a) > S-SO4(a) . According to the present and previous st udies the alginite sequence of the Kossen facies may, serve as a poten tial oil-source rock for petroleum found in the Zala basin. Presumably , the greater than or equal to 20 % of the sulphur content belonging t o the Nagylengyel-type petroleum might have originated in the Kossen F ormation.