Imperial College London
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Dr Susan H. Little

Faculty of Engineering, Department of Earth Science & Engineering

Honorary Research Fellow
 
 
 
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s.little CV

 
 
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Location

 

Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Little:2013:10.1016/j.gca.2013.07.046,
author = {Little, SH and Vance, D and Walker-Brown, C and Landing, WM},
doi = {10.1016/j.gca.2013.07.046},
journal = {Geochimica et Cosmochimica Acta},
pages = {673--693},
title = {The oceanic mass balance of copper and zinc isotopes, investigated by analysis of their inputs, and outputs to ferromanganese oxide sediments},
url = {http://dx.doi.org/10.1016/j.gca.2013.07.046},
volume = {125},
year = {2013}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The oceanic biogeochemical cycles of the transition metals have been eliciting considerable attention for some time. Manyof them have isotope systems that are fractionated by key biological and chemical processes so that significant informationabout such processes may be gleaned from them. However, for many of these nascent isotopic systems we currently know toolittle of their modern oceanic mass balance, making the application of such systems to the past speculative, at best. Here weinvestigate the biogeochemical cycling of copper (Cu) and zinc (Zn) isotopes in the ocean. We present estimates for the isotopiccomposition of Cu and Zn inputs to the oceans based on new data presented here and published data. The bulk isotopiccomposition of dissolved Cu and Zn in the oceans (d65Cu +0.9&, d66Zn +0.5&) is in both cases heavier than their respectiveinputs (at around d65Cu = +0.6& and d66Zn = +0.3&, respectively), implying a marine process that fractionates themand a resulting isotopically light sedimentary output. For the better-known molybdenum isotope system this is achieved bysorption to Fe–Mn oxides, and this light isotopic composition is recorded in Fe–Mn crusts. Hence, we present isotopic datafor Cu and Zn in three Fe–Mn crusts from the major ocean basins, which yield d65Cu = 0.44 ± 0.23& (mean and 2SD) andd66Zn = 1.04 ± 0.21&. Thus for Cu isotopes output to particulate Fe–Mn oxides can explain the heavy isotopic compositionof the oceans, while for Zn it cannot. The heavy Zn in Fe–Mn crusts (and in all other authigenic marine sediments measuredso far) implies that a missing light sink is still to be located. These observations are some of the first to place constraints on themodern oceanic mass balance of Cu and Zn isotopes.
AU  - Little,SH
AU  - Vance,D
AU  - Walker-Brown,C
AU  - Landing,WM
DO  - 10.1016/j.gca.2013.07.046
EP  - 693
PY  - 2013///
SN  - 1872-9533
SP  - 673
TI  - The oceanic mass balance of copper and zinc isotopes, investigated by analysis of their inputs, and outputs to ferromanganese oxide sediments
T2  - Geochimica et Cosmochimica Acta
UR  - http://dx.doi.org/10.1016/j.gca.2013.07.046
UR  - http://hdl.handle.net/10044/1/26491
VL  - 125
ER  -
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