10.1594/PANGAEA.757151
Pedersen, Thomas F
Thomas F
Pedersen
Shimmield, Graham
Graham
Shimmield
Chemistry of interstitial waters of ODP Leg 117 samples (Table 1)
PANGAEA
1991
Event label
Sample code/label
DEPTH, sediment/rock
pH
Alkalinity, total
Salinity
Magnesium
Calcium
Chloride
Sulfate
Phosphate
Ammonium
Silicon dioxide
Magnesium/Calcium ratio
Carbon, organic, dissolved
Drilling/drill rig
Composite Core
DSDP/ODP/IODP sample designation
Leg117
Joides Resolution
Ocean Drilling Program (ODP)
1987-08-29T11:15:00/1987-10-09T16:45:00
en
Supplementary Dataset
10.2973/odp.proc.sr.117.152.1991
2195 data points
text/tab-separated-values
Creative Commons Attribution 3.0 Unported
Interstitial water analyses made at 12 sites during Leg 117 are used to define the nature of diagenetic reactions in organic-rich sediments on the Owen Ridge and Oman Margin. Minor variations in chloride concentration profiles are ascribed to past changes in bottom water salinity at two mid-depth margin sites and to upward migration of low salinity water at another. There is no evidence for subsurface brine movement, unlike the case on the Peru Margin. Dolomitization is widespread and accounts for the depletions of magnesium observed in pore waters at variable depths at nearly all sites. The mineral occurs both as disseminated euhedral limpid crystals and, in at least one location, in massive stringers. Formation of the latter is suggested to reflect precipitation during sea level transgressions when the sedimentation rate was low, but when productivity was high. Authigenic carbonate fluorapatite is also widespread, the phosphorus being derived from the breakdown of organic matter. Sulfate is quantitatively depleted at depth at most locations but the rate of depletion is markedly less than that observed on the Peru Margin where sedimentation is also similarly influenced by high rates of upwelling. The reason for this contrast is not clear and merits further investigation.
Supplement to: Pedersen, Thomas F; Shimmield, Graham (1991): Interstitial water chemistry, Leg 117: contrasts with the Peru margin. In: Prell, WL; Niitsuma, N; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 117, 499-513
57.3715
60.744
16.1307
18.4873
Arabian Sea