Stable and radiogenic isotope ratios in pore waters from ODP Leg 127 sites


Autoria(s): Brumsack, Hans-Jürgen; Zuleger, Evelyn; Gohn, E; Murray, Richard W
Cobertura

MEDIAN LATITUDE: 41.410500 * MEDIAN LONGITUDE: 137.786325 * SOUTH-BOUND LATITUDE: 38.616000 * WEST-BOUND LONGITUDE: 134.536000 * NORTH-BOUND LATITUDE: 43.987000 * EAST-BOUND LONGITUDE: 139.414000 * DATE/TIME START: 1989-06-26T15:15:00 * DATE/TIME END: 1989-08-04T17:00:00

Data(s)

19/01/1992

Resumo

Interstitial waters from four sites of the Japan Sea (794 to 797) have been analyzed for stable isotopes (delta D, delta11B, delta18O, and delta34S) and 87Sr/86Sr, besides major and minor ions. The isotopic composition is dominated by organic matter degradation, alteration of ash layers and volcaniclastic sands, silica transformation (opal A/CT), and basement alteration. Organic matter degradation and corresponding sulfate reduction leads to 32S depletion and is dependent upon sedimentation rate. The remaining sulfate reservoir is characterized by very "heavy" delta34S ratios, up to +93 ? (rel. CDT = Canyon Diabolo Troilite). "Barite fronts," which may develop in such sediments, should also be characterized by very "heavy" sulfur isotopes. The alteration of volcaniclastic material in the Quaternary sections influences the delta18O (-1.5 ? shift) and delta11B (desorption and later adsorption of "labile"11B). A pronounced positive delta11B anomaly at Site 795 represents the depth range of preferential 10B uptake by alteration products of the ash layers. At Site 796 delta D, delta11B, and 87Sr/86Sr are severely affected by alteration processes of volcaniclastic sands. The opal A/CT transformation may influence the oxygen isotopes and serves as a potential source for B, which is liberated at this interval at Site 795. This positive B anomaly is not reflected in the delta11B profile. Basement alteration processes dominate the sedimentary sequence below the opal A/CT transition, which serves as a chemical and physical boundary. The decreases in delta D and delta18O are probably related to a "paleo ocean water reservoir" situated in the permeable Layer II of the oceanic crust, as is indicated by the positive correlation between these two parameters. Besides Mg, alkalies and delta18O basement rocks also serve as a sink for 11 B (Site 795) and are the source for the Ca and Sr increases, as is documented by the less radiogenic 87Sr/86Sr ratio. 87Sr/86Sr ratios for the lowermost pore waters from Site 795 (0.70529) are comparable to those from volcaniclastic rocks from the "Green Tuff' region (0.704 to 0.706) and oil field brines from the Niigata Oil Field.

Formato

application/zip, 8 datasets

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.711481

doi:10.1594/PANGAEA.711481

Idioma(s)

en

Publicador

PANGAEA

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Brumsack, Hans-Jürgen; Zuleger, Evelyn; Gohn, E; Murray, Richard W (1992): Stable and radiogenic isotopes in pore waters from Leg 127, Japan Sea. In: Pisciotto, KA; Ingle, JCJr.; von Breymann, MT; Barron, J; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 127/128(1), 635-650, doi:10.2973/odp.proc.sr.127128-1.165.1992

Palavras-Chave #[SO4]2-; 127-794A; 127-794B; 127-795A; 127-795B; 127-796A; 127-796B; 127-797B; 87Sr/86Sr; B; Boron; d11B; d18O H2O; d34S; dD; delta 11B; delta 18O, water; delta 34S; delta Deuterium; Depth; DEPTH, sediment/rock; DRILL; Drilling/drill rig; Event; ICP-AES, Inductively coupled plasma - atomic emission spectroscopy; Japan Sea; Joides Resolution; Label; Leg127; Mass spectrometer Finnigan MAT 251; Mass spectrometer Finnigan MAT 261; Ocean Drilling Program; ODP; ODP sample designation; Sample code/label; Sr; Strontium; Strontium 87/Strontium 86 ratio; Sulphate
Tipo

Dataset