Isotope ratios of smectites, calcites and whole rocks from DSDP Legs 51 and 52, Atlantic Ocean
Delta180 and 87Sr/86Sr isotopic data from smectites, calcites, and whole rocks, together with published isotopic age determinations, alkali element concentration data and petrographic observations suggest a sequential model of ocean floor alteration. The early stage lasts about 3 m.y. and is charact...
Main Authors: | , , , |
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Format: | Dataset |
Language: | English |
Published: |
PANGAEA
1981
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Subjects: | |
Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.667373 https://doi.org/10.1594/PANGAEA.667373 |
Summary: | Delta180 and 87Sr/86Sr isotopic data from smectites, calcites, and whole rocks, together with published isotopic age determinations, alkali element concentration data and petrographic observations suggest a sequential model of ocean floor alteration. The early stage lasts about 3 m.y. and is characterized by palagonite and smectite formation, and solutions with a large basaltic component, increasing with temperature which varies from 15° to 80° C at DSDP site 418A. Most carbonates are deposited after this stage from solutions with a negligible basaltic Sr component and temperatures of 15° to 40° C. Water of seawater Sr and O isotopic composition is shown to percolate to at least 500 m into the basaltic basement. No evidence was found for continuing exchange of strontium or oxygen after 3 m.y. |
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