87Sr/88Sr and 18O/16O ratios, interstitial water chemistry and diagenesis in deep-sea carbonate sediments of the Ontong Java Plateau

Online Access: Get full text
doi: 10.1016/0016-7037(82)90199-5
Author(s): Elderfield, Henry; Gieskes, Joris M.; Baker, Paul A.; Oldfield, R. K.; Hawkesworth, C. J.; Miller, R.
Author Affiliation(s): Primary:
Univ. Leeds, Dep. Earth Sci., Leeds, United Kingdom
Other:
Scripps Inst. Oceanogr., United States
Volume Title: Geochimica et Cosmochimica Acta
Source: Geochimica et Cosmochimica Acta, 46(11), p.2259-2268. Publisher: Pergamon, Oxford, International. ISSN: 0016-7037 CODEN: GCACAK
Note: In English
Summary: Sr/Ca ratios are species-dependent in unaltered foraminifera from DSDP Site 289 and atom ratios (1.2-1.6 X 10-3) exceed those predicted by distribution coefficient data (approx 0.4 X 10-3). During diagenesis Sr/Ca ratios of carbonates decrease and reach the theoretical distribution at a depth which is identical to the depth of Sr-isotopic equilibration. Mg/Ca ratios in the carbonates do not increase with depth as found in some other DSDP sites. Interstitial 18O/16O ratios increase with depth at site 289 to delta 18O = 0.67per mille (SMOW), reflecting carbonate recrystallization at elevated T (= or >20°C). Interstitial Sr2+ concentrations reach high levels, up to 1 mM, chiefly because of carbonate recrystallization. However, 87Sr/86Sr ratios decrease from 0.7092 to <0.7078, lower than for contemporaneous sea-water, showing that there is a volcanic input of Sr at depth. This volcanic component is recorded in the Sr- isotopic composition of recrystallized calcites. Isotopic compositions of the unrecrystallized calcites suggests that the rate of increase of the 87Sr/86Sr ratio of sea-water with time has been faster since 3 m.y. ago than in the preceding 13 m.y.
Year of Publication: 1982
Research Program: DSDP Deep Sea Drilling Project
Key Words: 02 Geochemistry; Alkaline earth metals; Carbonate sediments; DSDP Site 288; DSDP Site 289; Deep Sea Drilling Project; Deep-sea environment; Diagenesis; Foraminifera; Geochemistry; Invertebrata; Isotopes; Leg 30; Marine environment; Marine sediments; Metals; Microfossils; O-18/O-16; Oxygen; Pacific Ocean; Pore water; Protista; Ratios; Sediments; Sr-87/Sr-86; Stable isotopes; Strontium; Volcanism; West Pacific
Coordinates: S100000 S000000 E1650000 E1550000
Record ID: 1983015906
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom