Preliminary organic geochemical investigation of Upper-Jurassic dolomites of Plješvica (Yugoslavia)

Abstract The amounts and compositions of the total and soluble organic matter were determined in 17 samples of Upper Jurassic dolomites from the slopes of the mountain Pljesivica (Lika, Yugoslavia; locations Vrelo-Mrsinj Grad, Vrelo-Draga Zubovica and Zavalje-Bela Greda). The content of the total organic matter was found to vary from 0.06 to 6.57%, with the exception of sample 8, containing a markedly higher amount of organic matter, 68.42%. The quantity of soluble organic matter in most of the samples, especially those from Zavalje, was higher than 10% of the total organic matter. The proportions of saturated and aromatic hydrocarbons and NSO constituents in the soluble organic matter were determined. In the n alkane fractions homologous series members from C 22 to C 28 predominated with the CPIs being around 1. Antibiotic effects of some bitumen constituents of smaple 8 were observed.