This study investigates the δ18O of pore waters from Sites 1003 through 1007, drilled along the western margin of the Great Bahama Bank during Leg 166 of the Ocean Drilling Program. These pore waters generally show a positive correlation between δ18O and the concentration of chloride. The exception to this trend is Site 1006, where the pore waters exhibit nonlinear behavior with respect to chloride. The correlation between the concentration of Cl- and δ18O at most of the sites appears to be a coincidence because although the increase in Cl- is a result of diffusion from an underlying source, the increases in δ18O result from the recrystallization of metastable carbonates in the presence of a geothermal gradient. The difference in behavior in the δ18O of the pore water at Site 1006 is probably a result of the relative reduced rate of carbonate recrystallization at this site. The δ18O of the pore waters in the upper portion of the cores shows a pattern similar to the concentration of chloride in that there is an interval of 30-50 m in which neither the δ18O nor the concentration of Cl- changes. This interval is consistent with either an interval of very rapid deposition of sediment or the advection of fluid through the platform. Both the δ18O and the concentration of Cl- increase toward the platform, suggesting an input of saline and isotopically heavy water from the platform surface.
|Original language||English (US)|
|Number of pages||8|
|Journal||Proceedings of the Ocean Drilling Program: Scientific Results|
|State||Published - Jan 1 2000|
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