Marine Polyphosphate: A Key Player in Geologic Phosphorus Sequestration
Julia Diaz,1
Ellery Ingall,1*
Claudia Benitez-Nelson,2
David Paterson,3
Martin D. de Jonge,3
Ian McNulty,3
Jay A. Brandes4
The in situ or authigenic formation of calcium phosphate minerals in marine sediments is a major sink for the vital nutrient phosphorus. However, because typical sediment chemistry is not kinetically conducive to the precipitation of these minerals, the mechanism behind their formation has remained a fundamental mystery. Here, we present evidence from high-sensitivity x-ray and electrodialysis techniques to describe a mechanism by which abundant diatom-derived polyphosphates play a critical role in the formation of calcium phosphate minerals in marine sediments. This mechanism can explain the puzzlingly dispersed distribution of calcium phosphate minerals observed in marine sediments worldwide.
1 School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332-0340, USA.
2 Marine Science Program and Department of Geological Sciences, University of South Carolina, Columbia, SC 29208, USA.
3 Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA.
4 Skidaway Institute of Oceanography, 10 Ocean Science Circle, Savannah, GA 31411, USA.
Present address: Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia.
* To whom correspondence should be addressed. E-mail: ingall{at}eas.gatech.edu
