Based on maximum pyrolysis degradation temperatures of not more than 420 degrees C, all the shale samples are classified as immature, corresponding to a vitrinite reflectance of less than 0.45% R(r) and a lignite to sub-bituminous coal stage. This is confirmed by relatively high isoprenoid to n-alkane ratios as well as by high biomarker contents. According to this maturity stage, and both total organic carbon contents of 6-41% and hydrogen indices of 255-708 mg HC/g TOC, the Cenomanian-Turonian black shales exhibit fair to excellent source rock potential with mixed Type II and Type I kerogen. Relatively high isoprenoid to n-alkane ratios may indicate at least partial (bio-) degradation/evaporation/waterwashing and selective modification of the lipid composition due to the nature of the outcrop. However, very similar unimodal n-alkane distributions in the gas chromatograms of four selected shale samples, with a predominance in the C(16) to C(17) region, clearly point to a significant contribution of algal and/or bacterial type organic matter with low terrigenous organic input. C(27), C(28) and C(29) steranes in shales from both formations have similar distributions (C(29)> C(27)> C(28)). High C(31) R homohopane / C(30) hopane ratios indicate a marine depositional environment. This is confirmed by the presence of gammacerane in all the black shales investigated which in general indicates salinity. Pregnanes in one sample (BA-6) may point to hypersaline conditions.