This article has been retracted at the request of the editor as the authors have plagiarized part of papers that had already appeared in Chem. Geol. 209 (2004) 271–294, doi:10.1016/j.chemgeo.2004.06.012 and Geochim. Cosmochim. Acta 67 (2003) 2321–2339, doi:10.1016/S0016-7037(02)01413-8. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and has not appeared in a publication elsewhere. Re-use of any data should be appropriately cited. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and we apologize to readers of the journal that this was not detected during the submission process.