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Jellyfish Lake, Palau: Regeneration of C, N, Si, and P in anoxic marine lake sediments
Author(s) -
Lyons W. Berry,
Lent Robert M.,
Burnett William C.,
Chin Philip,
Landing William M.,
Orem William H.,
McArthur John M.
Publication year - 1996
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1996.41.7.1394
Subject(s) - authigenic , anoxic waters , alkalinity , pore water pressure , carbonate , sediment , seawater , geology , environmental chemistry , mineralogy , terrigenous sediment , oceanography , diagenesis , chemistry , geomorphology , geotechnical engineering , organic chemistry
Sediment cores from Jellyfish Lake were processed under an inert atmosphere and the pore waters extracted and analyzed for the following parameters: pH, titration alkalinity (TA), Cl − , H 4 SiO 4 , PO 4 3− , NH 4 + , Ca 2+ , Mg 2+ , SO 4 2− , and H 2 S. Additionally, in one set of pore‐water samples (core 10), the δ 13 C of the ∑CO 2 was also determined. The TA, H 4 SiO 4 , PO 4 3− , NH 4 + , and H 2 S increased with depth in the pore waters above anoxic bottom‐water values. H 2 S values increased to 3.8 M. In one case, both H 4 SiO 4 and PO 4 3− concentrations increased to a maximum value and then decreased with depth, suggesting removal into solid phases. The H 4 SiO 4 concentrations are equal to or greater than pore‐water value observed in sediments underlying upwelling areas. PO 4 3− concentrations are, in general, lower than pore‐water values from terrigenous nearshore areas but higher than nearshore carbonate pore‐water values from Florida Bay or Bermuda. The Ca 2+ , Cl − , and Mg 2+ : Cl − ratios show slight decreases in the top 15–20 cm, suggesting that authigenic carbonate may be forming. This suggestion is supported by the fact that the pore waters are saturated with respect to CaCO 3 due to the very high TAs. The δ 13 C measurements of the pore‐water ∑CO 2 are from a shorter core. These measurements reach their most negative concentration at 72 cm and then become slightly heavier. This change is accompanied by a decrease in TA, suggesting the onset of methanogenesis at this location in this core.