Strontium and its isotopic composition in interstitial waters of marine carbonate sediments

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doi: 10.1016/0012-821X(86)90163-9
Author(s): Gieskes, J. M.; Elderfield, H.; Palmer, M. R.
Author Affiliation(s): Primary:
Scripps Inst. Oceanogr., La Jolla, CA, United States
Other:
Univ. Cambridge, Dep. Earth Sci., United Kingdom
Univ. Leeds, Dep. Earth Sci., United Kingdom
Volume Title: Earth and Planetary Science Letters
Source: Earth and Planetary Science Letters, 77(2), p.229-235. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X CODEN: EPSLA2
Note: In English. 26 refs.; illus. incl. 1 table
Summary: The concentrations and isotopic compositions of Sr in interstitial waters from several DSDP sites, where sediments consist chiefly of carbonate oozes and chalks, are used as indicators of carbonate diagenesis by reference to expected variations in the 87Sr/86Sr ratio of sea-water with time. Carbonate sediments of the Walvis Ridge show increases in interstitial Sr2+ concentrations in the upper carbonate-ooze sections, with the highest concentrations near the ooze-chalk boundary, where the maximum rates of carbonate recrystallization occur. Below this, in-situ production of Sr2+ diminishes and there is a diffusive flux of Sr to an underlying sink, presumably volcanogenic sediments or basalts, leading to Sr isotopic disequilibrium between carbonates and interstitial waters. In some other sites there is no apparent Sr sink at depth and isotopic equilibrium is retained. Overall, diffusive smoothing of profiles exerts an important control on the 87Sr/86Sr ratios, although lower ratios than contemporaneous sea-water values in the carbonate oozes often correlate with zones of Mg2+ loss and reflect a combination of a flux of Sr2+ from the zone of maximum recrystallization rates, together with a contribution from the in-situ alteration of volcanic matter. Ca, Mg, Sr and 87Sr/86Sr in interstitial waters of DSDP sites 315, 357, 525 and 528 are presented.
Year of Publication: 1986
Research Program: DSDP Deep Sea Drilling Project
Key Words: 02 Geochemistry; Alkaline earth metals; Alteration; Atlantic Ocean; Barbados Ridge; Carbonate sediments; Composition; Deep Sea Drilling Project; Diagenesis; Geochemistry; Isotopes; Metals; North Atlantic; Pore water; Recrystallization; Sediments; South Atlantic; Sr-87/Sr-86; Stable isotopes; Strontium; Walvis Ridge
Record ID: 1986046252
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom

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