Abstract
Metalliferous sediments from the Atlantis II Deep, Red Sea, exhibit significant vertical variations in the composition and distribution of the mineral phases. Although the sediment facies classified earlier can be recognized in the core, some fluctuations exist due to the elemental migration, external mineral contribution and diagenetic processes. The carbonate minerals constitute considerably thick layers in the sediments and need to be characterized as a separate facies. Sulfate-sulfide, sulfate-oxide, sulfate-carbonate and carbonate-sulfide associations are considered to have been developed due to mixing of different mineral phases formed under specific conditions either during deposition or after burial.