A geochemical study of dolomite in the Monterey Formation, California.
Monterey sections with dolomites with low trace-element contents contain higher percentages of dolomite and have lower sedimentation rates and lower detrital mineral contents than sections with dolomites with high trace-element contents. Differences in iron and manganese contents of dolomites from different sections are probably attributable to variation in the amount of readily available iron and possible manganese oxide coatings on detrital minerals. Whether a dolomite forms in or below the zone of organic-matter oxidation by microbial sulfate reduction also may affect the availability of iron and manganese. In the zone of sulfate reduction, reduced iron, and possibly manganese, may be precipitated as sulfide minerals rather than be incorporated into dolomite. -from Authors
