Abstract
The SEDEX method, a sequential extraction scheme for sedimentary phosphorus phases, was tested for use on eastern Mediterranean sediments using two in-house reference sediments. In addition a 2 M NH4Cl and a 0.1 M NaOH extraction were tested to extract CaCO3-associated and iron-bound P respectively. These methods were then applied to samples of a sediment core from the eastern Mediterranean (ABC26). The sum of extracted P phases of the reference sediments (and core ABC26) was not significantly different from total P and precision of each extraction was better then 17% (1s), except for detrital P and iron-bound P (extracted by CDB). The NaOH extraction dissolved only iron-oxides associated with the surface of minerals, while the CDB extraction dissolved a much larger fraction. In core ABC26, P produced in the sapropel layer (S1) appeared to have diffused both upwards and downwards. This P is now found as exchangeable+loosely bound P and as iron oxide bound P in the adjacent oxic sediments. There was evidence that P was released from CaCO3 P in the 'burn-down' zone which was affected by sulfide oxidation. The organic C/P molar ratio was ~400:1 in the sapropel while it was indeterminate for the oxic layers.
Original language | English |
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Pages (from-to) | 147-155 |
Number of pages | 9 |
Journal | Marine Geology |
Volume | 139 |
Issue number | 1-4 |
DOIs | |
State | Published - Jun 1997 |
Externally published | Yes |
Keywords
- Eastern Mediterranean
- Phosphorus
- Sapropel
- Sequential extraction
ASJC Scopus subject areas
- Oceanography
- Geology
- Geochemistry and Petrology