Synchronous variations in the content of magnetic minerals and planktonic-foraminiferal δ13C in deep-sea sediments

A correlation between magnetic mineral contents and δ13C was obtained using two deep-sea sediment cores having distinctly different sedimentation rates, taken from the western equatorial Pacific. It was inferred that the fluctuations in the content of magnetic minerals, predominantly of bacterial origin, are caused mostly by variations in CaCO3 dissolution. The correlation seems to originate from changes in the vertical distribution of nutrients and carbon with isotopic fractionation.