1996/11/01 by Caroline P. Slomp, Eric H. G. Epping, Eric Epping +4 · 2 citations
Chemistry · Earth and Planetary Sciences · #Geochemistry and Elemental Analysis #Groundwater and Isotope Geochemistry #Radioactive element chemistry and processing
paper · doi:10.1357/0022240963213745
crossref issued 1996/11/01 · crossref published 1996/11/01 · crossref published-print 1996/11/01 · openalex publication_date 1996/11/01 · crossref created 2005/03/05 · crossref deposited 2011/08/20 · openalex created_date 2025/10/10 · crossref indexed 2026/07/27 · openalex updated_date 2026/08/01
A combination of pore water and solid phase analysis was used to determine whether authigenic carbonate fluorapatite (CFA) is currently forming in the sediment at two locations (OMEX I and II) on the North Atlantic continental platform Goban Spur (southwest of Ireland). Results of selective P extractions suggest that an early diagenetic redistribution of Fe-bound P to an authigenic P phase may be occurring at both stations. A steady-state diagenetic model describing the depth profiles of pore water HPO 4 2- and three solid phase forms of P (organic P, Fe-bound P and authigenic P) was developed and applied to the data of station OMEX-I. The model results indicate that CFA formation can account for the observed increase of authigenic P with depth at this station. Furthermore, the results show that an intense cycling of P between Fe-bound P and pore water HPO 4 2- at the redox interface can create conditions beneficial for CFA formation. This internal P cycle is driven by downward, bioturbational transport of mainly in-situ-formed Fe-bound P into the reduced sediment zone. Losses from the internal P cycle due to CFA formation and HPO 4 2- diffusion are compensated for by sorption of HPO 4 2- released from organic matter to Fe oxides in the oxidized surface sediment. Fe-bound P thus acts as an intermediate between organic P and CFA. CFA can account for between 25 and 70% of the total burial flux of reactive P at station OMEX-I and thus may act as an important sink for P in this low sedimentation, continental margin environment.