2. Paleo-watermass mixing and circulation

As well as proxies for salinity and temperature, the geochemical and isotopic signatures recorded in foraminifera are used to reconstruct ocean circulation and water mass mixing in the past. The most prominent example is the radiogenic isotope signature of the rare earth element (REE) neodymium (Nd). Similar to other trace metals, neodymium is supplied to the oceans via weathering of continental material and is then distributed via ocean currents. The radiogenic isotope signature of Nd (143Nd/144Nd) in a water mass depends on the composition of the continental rocks close to the area of water mass formation and can vary widely. As Nd has a relatively long residence time in the ocean of at least 100 years, the Nd-isotope signal of seawater can be used as a quasi-conservative tracer and mixing proxy for water masses. In order to reconstruct the isotope signature of surface and deep waters from ocean sediments, benthic and planktonic foraminifera undergo an extensive cleaning process prior to analysis.

MOW Reconstruction
Indonesian Throughflow
Arctic-Atlantic Exchange
Hf-Nd Isotopes in the Arctic Ocean
Pliocene Circulation of the Atlantic
Circulation in the Cretaceous
Bering Sea
Unraveling the Onset and Spread of Cretaceous Anoxia
Reconstruction of watermass circulation in the Labrador Sea

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