Stable isotope ratios of interstitial fluids from ODP Leg 110 sites, supplement to: Vrolijk, Peter J; Chambers, Steven R; Gieskes, Joris M; O´Neil, J R (1990): Stable isotope ratios of interstitial fluids from the northern Barbados Accretionary Prism, ODP Leg 110. In: Moore, JC; Mascle, A; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 110, 189-205


Delta18O values of pore waters from the northern Barbados accretionary prism range from -0.3 to -3.6 per mil and reflect pervasive reaction of volcanic ash to form smectite within the sedimentary sequence and continued low temperature alteration of basalt in the underlying ocean crust with the overprint of diffusive exchange between water in the sediment pores and the open ocean. Delta D values of pore waters in sediments sampled seaward of the deformation front drop from +5 per mil at the sediment surface to -6 per mil at the deepest levels sampled. These changes may also be related to alteration processes but remain largely enigmatic. Sediment deformation caused by impingement of the Caribbean plate on the Atlantic plate has instigated migration of chemically and isotopically distinct fluid along faults and coarse-grained sedimentary beds; delta18O values of pore waters are also locally affected by thrust stacking which increases diffusive pathlengths and possibly modifies diagenetic reaction rates in Pleistocene sediments. Migrating fluids are distinguished by anomalous delta18O values that are as much as 1 per mil higher than those of surrounding fluids. Uncertainties in hydrogen isotope fractionation resulting from processes occurring under these conditions hinder identification of the hydrogen isotope composition of expelled fluid. Stable isotope analyses of pore waters help constrain the fluid migration history of the accretionary prism by limiting the source of fluids, the paths along which fluid flows, and the timing of faulting and subsequent fluid flow.

Metadata Access
Creator O´Neil, J R;Chambers, Steven R;Vrolijk, Peter J;Gieskes, Joris M
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 1990
Rights Creative Commons Attribution 3.0 Unported (CC-BY)
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Discipline Earth System Research
Spatial Coverage (16N-16N,59W-59W)
Temporal Point 1986-06-28T11:59:59Z