The quantitative distribution of carotenoids in sediments of Pleistocene to Miocene age from the Peru upwelling area is reported. Major pigments include beta-carotene, diatoxanthin, caroteno-3,3'-diols from phytoplankton, astaxanthin and canthaxanthin from crustaceans, and spheroidenone from bacteria. beta-carotene epoxides are major consituents, representing transformation products in the degradation of beta-carotene to low molecular weight compounds. The absolute abundance of carotenoids reflects bottom-water oxicity at the time of deposition; highest concentrations of carotenoids were observed in laminated muds deposited within the oxygen-minimum zone, with reduced or negligible concentrations of pigments observed in bioturbated sequences deposited during periods of well-oxygenated bottom water. beta-carotene, the most abundant pigment in recently deposited sediments, slowly degrades through a sequence of transformation reactions initiated by epoxidation. The 4,4' dioxo-carotenoids, which are unable to form 5,6-epoxides, have been preferentially preserved in these sediments.

Supplement to: Repeta, Daniel J (1990): Carotenoid diagenesis in Pleistocene to Miocene sediments from the Peru Margin. In: Suess, E; von Huene, R; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 112, 567-572