Rare earth element phase distributions in a deep-sea carbonate sediment

Northeastern Atlantic sedimentary rare earth element (REE) (La, Ce, Nd, Sm, Eu, Tb, Yb and Lu) phase associations among CaCO₃, authigenic and lithogenic material are estimated from total sediment REE, Al, Ca, Si, Mn and Co abundances using a linear correlation technique. Phase associations were also determined using a selective chemical leaching technique specific for CaCO₃+exchangeable cation, easily reducible oxyhydroxide and residual material. Results suggest that 25–50% of the REE associated with the clay material are exchangeable cations and 20–35% of the total 3+REE and 4% of the total Ce reside in coatings on the CaCO₃ tests.