Constraints on water transport and alteration in the oceanic crust from the isotopic composition of pore water

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doi: 10.1029/JB086iB09p07924
Author(s): Lawrence, J. R.; Gieskes, Joris M.
Author Affiliation(s): Primary:
Lamont-Doherty Geol. Obs., Palisades, NY, United States
Scripps Inst. Oceanogr., United States
Volume Title: Journal of Geophysical Research
Source: Journal of Geophysical Research, 86(B9), p.7924-7934. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0148-0227
Note: In English. Lamont-Doherty Geol. Obs.; Contrib. No. 3198. 36 refs.; illus. incl. 36 anals., 3 tables, sketch map
Summary: The oxygen isotopic compositions of pore fluids from sediments of older oceanic crust commonly de-crease with depth. Increases in calcium ion concentrations always accompany the 18O/16O decreases.These changes are attributed principally to the alteration of basalts or alteration of volcanic ash in the sediments. Oxygen isotope material balance calculations suggest that 5-20% of the upper kilometer of ba-salt is altered at the time of subduction of the oceanic crust. This corresponds to a flux of 18O into the oceanic crust of 2.3 × 1015 moles per million years. Evaluation of the oxygen and hydrogen isotope data from the pore fluids also suggests that the principal process of mass transfer in the sediments of older oceanic crust is diffusion. Convection of water in the basalts of the oceanic crust appears to continue until subduction.
Year of Publication: 1981
Research Program: DSDP Deep Sea Drilling Project
Key Words: 02 Geochemistry; Alkaline earth metals; Basalts; Calcium; Convection; Crust; D/H; Data; Deep Sea Drilling Project; Deuterium; Diffusion; Geochemistry; Hydrogen; Igneous rocks; Isotopes; Marine sediments; Mass transfer; Metals; O-18/O-16; Oceanic crust; Oxygen; Pore water; Processes; Sediments; Stable isotopes; Volcanic ash; Volcanic rocks; World ocean
Record ID: 1982015061
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.

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