Diagenetic migration of sulfides in sediments accumulated in different sedimentation settings

摘要

Migration and accumulation of sulfides at the contact of lithologically and geochemically different layers are considered. The possible mechanisms (gravitational, diffusion, elision, and electrogeochemical) for sulfide transportation during diagenesis are discussed. Data are presented to explain the localization of sulfide minerals at the boundary of reduced and oxidized sediments. The paper considers examples of stratiform sulfide concentrations of not only ore grade, but also lower grade, which, however, are of great significance for understanding the formation conditions of some geochemical anomalies. Link between the diagenetic migration of sulfides and the formation of iridium anomaly is substantiated. [PUBLICATION ABSTRACT]