Strontium isotopic composition of interstitial waters from DSDP sites 25-245 and 38-336

Measurements of 87Sr/86Sr ratios of interstitial waters from leg 25, site 245 and leg 38, site 336 of the Deep Sea Drilling Project show that the enrichment of Sr[2+] with depth is caused both by the alteration of volcanic material and by the introduction of strontium derived from calcium carbonate....

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Bibliographic Details
Main Authors: Hawkesworth, Chris J, Elderfield, Henry
Format: Dataset
Language:English
Published: PANGAEA 1978
Subjects:
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.710844
https://doi.org/10.1594/PANGAEA.710844
Description
Summary:Measurements of 87Sr/86Sr ratios of interstitial waters from leg 25, site 245 and leg 38, site 336 of the Deep Sea Drilling Project show that the enrichment of Sr[2+] with depth is caused both by the alteration of volcanic material and by the introduction of strontium derived from calcium carbonate. 87Sr/86 Sr ratios range from 0.70913 to 0.70794 at site 245 and from 0.70916 to 0.70694 at site 336. The low ratios compared with contemporaneous seawater reflect the release of Sr from a volcanic source having, according to material-balance calculations, a 87Sr/86 Sr ratio of about 0.7034 at site 336. At this site the source appears to be volcanic ash and not basaltic basement which acts as a sink for Sr[2+] during in situ low-temperature weathering. The volcanic contribution to the strontium enrichment in the basal interstitial waters varies from <10% at site 245 to >50% at site 336. The remaining Sr[2+] is derived from Sr-rich biogenic carbonate during diagenetic recrystallization to form Sr-poor calcite.