Huang, Kuo-Fang et al. (2005): Geochemistry of major constituents, boron and boron isotopes in pore waters from ODP Site 1202, Okinawa Trough

ODP 195
ODP 195 1202

Huang, Kuo-Fang
National Cheng Kung University, Department of Earth Sciences, Tainan, Taiwan

You, Chen-Feng
National Taiwan Normal University, Taiwan

She, Min-Lin
National Cheng Kung University, Taiwan

Lin, Hui-Ling
National Sun Yat-Sen University, Taiwan

Geochemistry of major constituents, boron and boron isotopes in pore waters from ODP Site 1202, Okinawa Trough
In: Wei, Kuo-Yen (editor), Mii, Horng-Sheng (editor), Huang, Chi-Yue (editor), Okinawa Trough; sedimentary processes and paleoenvironment
Institute of Earth Sciences Academia Sinica, Taipei, Taiwan
Forty-one interstitial water samples recovered from ODP Site 1202, Okinawa Trough, were analyzed for major constituents, B and delta (super 11) B. The geochemical results show that major constituents and boron content varied largely in pore fluids and possibly were affected by sulfate reduction, re-crystallization of biogenic carbonate or silica, ash alteration, and organic matter degradation. Mixing of fluids along high-porosity sandy layers or fracture zones also changes the pore water chemical compositions significantly. The down-core distribution of B and delta (super 11) B in the pore waters are sensitive tracers for assessing fluid migration and water/sediment interaction at various depths. Pore water B content at Site 1202 falls in a range between 0.25 and 1.16 mM compared to that of 0.42 mM in seawater. The delta (super 11) B values, however, vary considerably from approximately 32.7 to 50.9 per mil relative to the seawater value of 39.5 per mil. The delta (super 11) B vs. 1/B plot indicates that sedimentary B released from clays is the most important source to pore waters, resulting in elevated B with low delta (super 11) B. Other processes including precipitation of calcium carbonate, fluid advection through high-porosity permeable sandy horizons, interaction with terrigenous sediments and/or ash alteration may also modify the B and delta (super 11) B distributions.
Coverage:Geographic coordinates:
West:122.3000East: 122.3100

General geochemistry; B-11/B-10; boron; chemical composition; geochemistry; isotopes; Leg 195; lithostratigraphy; marine sediments; North Pacific; Northwest Pacific; Ocean Drilling Program; ODP Site 1202; Okinawa Trough; Pacific Ocean; pore water; sediments; stable isotopes; West Pacific;