Solid bitumens from the Seridhalivein, occurring in the Upper Cretaceous - Palaeocene Germav Formation, and five oils from different oilfields in SE Turkey, were investigated by a variety of organic geochemical methods. Based on biomarker distributions (pristane/phytane, carbon number preference (CPI), norhopane/hopane, extended hopane distribution, pregnanes/regular steranes), a marine carbonate depositional environment is inferred for the source of these oils. The oils are ＇＇early mature ＇＇, as indicated by their ethylcholestane 20S/20S+20R ratios, and the 17 alpha(H),21 beta(H)-bishomohopane 22S/22S+22R ratios. Differences in relative abundance of some compounds typical of higher salinities in the depositional environment (docosane, pregnane) suggest different sources or facies variations within a common source. No aromatic sulfur compounds were detected in the oils. The solid bitumens were characterized by a high abundance of dibenzothiophenes, naphthalenes, phenanthrenes and their alkyl-substituted homologues in the aromatic fractions, and an abundance of n-alkanes in the saturate fraction. The high maturity of the solid bitumen (epi-impsonite, R(o) %equiv. similar to 1.2) makes an interpretation on the origin of these substances difficult An origin due to biodegradation of sulfur-rich oil is excluded, sines the alkane and aromatic fractions do not show signs of a severe microbial degradation. The absence of sulfur compounds in the oil extracts and the pyrolysis products of the asphaltene fraction show genetic differences between the oils and solid bitumens of SE Turkey. Pyrolysis of the asphaltenes from the bitumen extracts and of the unextracted bitumens produced sulfur compounds similar to those found in the aromatic fraction.