The Isotopic Distribution of Hafnium in Seawater

ABSTRACT

OCE-0117437

A researcher from Cornell University plans to measure the hafnium (Hf) isotopic composition (176Hf/177Hf) and eHf values (isotopic composition of Hf normalized to CHUR, a chondrite with a 176Hf/177Hf ratio of 0.282772) of seawater samples recovered from both the Atlantic (North Atlantic Deep Water, Arctic Intermediate Water, Mediterranean Outflow Water and modified Antarctic Intermediate and Deep Water) and Pacific Ocean (Equatorial Water, Arctic Intermediate Water, North Central Pacific Water and Ocean Common Water). In addition, the PI will analyze hydrothermal fluids from 9'N on the East Pacific Rise and metalliferous sediments collected from the Nazca Plate. The goal of these measurements is to provide new insights into the geochemistry of this element and ascertain that ferromanganese crusts indeed record the composition of Hf in seawater. If ferromanganese crust record seawater Hf concentrations, then the PI contends that the isotopic composition of Hf can be used as a paleo indicator of weathering intensity.