Filippelli, Gabriel M; Delaney, Margaret Lois (1995): Phosphorus geochemistry of eastern equatorial Pacific Ocean sediments. PANGAEA, https://doi.org/10.1594/PANGAEA.808983, Supplement to: Filippelli, GM; Delaney, ML (1995): Phosphorus geochemistry and accumulation rates in the eastern equatorial Pacific Ocean: results from Leg 138. In: Pisias, NG; Mayer, LA; Janecek, TR; Palmer-Julson, A; van Andel, TH (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 138, 757-767, https://doi.org/10.2973/odp.proc.sr.138.144.1995
Always quote citation above when using data! You can download the citation in several formats below.
We determined phosphorus (P) concentrations in Leg 138 sediment samples from Sites 844, 846, and 851, using a sequential extraction technique to identify the P associated with five sedimentary components. Total concentrations of P (sum of the five components) ranged from 4 to 35 µmol P/g sediment, with mean values relatively similar between the three sites (11, 14, and 12 for Sites 844,846, and 851, respectively). Authigenic/biogenic P was the most important component in terms of percentage of total P (about 75%), with iron-bound P (13%), adsorbed P (2%-9%), and organic P (4%) of secondary importance; detrital P was a minor P sink (1%) in these sediments. Profiles of adsorbed P and iron-bound P show decreasing concentrations with age, indicating that these components have been affected by diagenesis and reorganization of P. A peak in iron-bound P may reflect higher fluxes of hydrothermally derived Fe to eastern equatorial Pacific Ocean sediments from 11 to 8 Ma. Lower detrital P values for western Site 851 reflect a greater distance of this site from a terrigenous source area, compared to that of Sites 844 and 846.
Phosphorus mass accumulation rates (P-MARs; units of µmol P/cm**2/k.y.) were calculated using total P concentrations (not including the minor and oceanically unreactive detrital P component) and sedimentation rates and dry-bulk densities averaged over time intervals of 0.5 m.y. P-MARs generally decrease from 17 Ma to the present. Eastern transect Sites 844 and 846 display a decrease in P-MARs from about 30 to 10 in the interval from 17 to 8 Ma, while western transect Site 851 is highly variable during this interval. P-MARs increase to about 45 and stay relatively high from 8 to 6 Ma, then decrease toward the present to some of the lowest values of the record (about 10). The general trend of high P-MARs at about 6 Ma and decreasing values toward the present is correlated with other geochemical and sedimentary trends through this interval and may reflect (1) a change in net sediment and P burial, (2) a reorganization of fluxes with no change of net burial, or (3) a combination of the two.
Median Latitude: 2.532253 * Median Longitude: -97.290173 * South-bound Latitude: -3.094930 * West-bound Longitude: -110.571800 * North-bound Latitude: 7.921310 * East-bound Longitude: -90.480760
Date/Time Start: 1991-05-11T10:24:00 * Date/Time End: 1991-08-09T06:00:00
Datasets listed in this publication series
- Filippelli, GM; Delaney, ML (2013): (Table A1) Sedimentation rates, dry-bulk density and component P concentrations of ODP Hole 138-844B. https://doi.org/10.1594/PANGAEA.808980
- Filippelli, GM; Delaney, ML (2013): (Table A2) Sedimentation rates, dry-bulk density and component P concentrations of ODP Hole 138-846B. https://doi.org/10.1594/PANGAEA.808981
- Filippelli, GM; Delaney, ML (2013): (Table A3) Sedimentation rates, dry-bulk density and component P concentrations of ODP Hole 138-851B. https://doi.org/10.1594/PANGAEA.808982