Shallow sediments from the Black Sea showed fatty acids to be present in large quantities, up to 4,200 µg per gram of dry sediment, comprising both saturated and unsaturated acids. Even-carbon saturated acids were dominant, and palmitic acid was the most abundant. Chlorin and porphyrin pigments also were abundant, totaling 1,600 µg/g; most of them were chlorin pigments. The sterol fraction contained a complex mixture of 15 or more compounds, two of which (cholesterol and campesterol) were identified. Mass spectra of the major sterol showed peaks at 428 and 430 amu, which may represent molecular ions, and major fragments at 287, 271, 316, and 229 amu. On the basis of gas chromatography, sterols totaled as much as 2,500 µg/g. A variety of carotenoid compou ds was present in substantially lower abundances--about 40 µg/g--and the principal pigment apparently was ß-carotene. Perylene appeared to be the dominant polycyclic aromatic among three general classes of aromatics totaling about 1 µg/g. No diagenetic transalkylation was evident in the aromatics.

The presence of the unusual sterols, the complexity of the chlorin pigments, and the disappearance of unsaturated fatty acids indicate considerable reduction, hydrolysis, and decarboxylation in the diagenesis of organic compounds in the Black Sea sediments.