Barium Isotopes

In the modern marine environment barium isotope (138Ba) variations are primarily driven by barite cyclingbarite incorporates ''light'' Ba isotopes from solution rendering the residual Ba reservoir enriched in ''heavy'' Ba isotopes by a complementary amount. Since the processes of barite precipitation and dissolution are vertically segregated and spatially heterogeneous barite cycling drives systematic variations in the barium isotope composition of seawater and sediments. This Element examines these variations; evaluates their global regional local and geological controls; and explores how 138Ba can be exploited to constrain the origin of enigmatic sedimentary sulfates and to study marine biogeochemistry over Earth''s history.