Digital Object Identifier (DOI)
Oceanic iron inputs must be traced and quantified to learn how they affect primary productivity and climate. Chemical reduction of iron in continental margin sediments provides a substantial dissolved flux to the oceans, which is isotopically lighter than the crust, and so may be distinguished in seawater from other sources, such as wind-blown dust. However, heavy iron isotopes measured in seawater have recently led to the proposition of another source of dissolved iron from ‘non-reductive’ dissolution of continental margins. Here we present the first pore water iron isotope data from a passive-tectonic and semi-arid ocean margin (South Africa), which reveals a smaller and isotopically heavier flux of dissolved iron to seawater than active-tectonic and dysoxic continental margins. These data provide in situ evidence of non-reductive iron dissolution from a continental margin, and further show that geological and hydro-climatic factors may affect the amount and isotopic composition of iron entering the ocean.
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Citation / Publisher Attribution
Nature Communications, v. 4, art. 2143
Scholar Commons Citation
Homoky, William B.; John, Seth G.; Conway, Tim M.; and Mills, Rachel A., "Distinct Iron Isotopic Signatures and Supply from Marine Sediment Dissolution" (2013). School of Geosciences Faculty and Staff Publications. 1546.