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Sr, C and O isotope ratios of Neogene sediments from DSDP Hole 38-341, Voring Plateau

Listed in PANGAEA and DataCite — shown once because both records carry DOI 10.1594/pangaea.714252

The Neogene sediments from DSDP site 341 on the Voring Plateau, Norwegian Sea, contain a thin glauconitic pellet-bearing subunit, which separates underlying pelagic clays from overlying glacial-marine sediments.

Description

Oxygen isotope measurements of benthic foraminifera show a delta18O shift of + 1 per mil during deposition of this subunit, probably a combined effect of a drop in bottom water temperature and a rise in seawater delta18O.

The chronology of this sedimentological and O isotope transition is, however, poorly constrained by fossil evidence. Rb-Sr dating of glauconitic pellets indicates that the lower part of the glauconitic subunit was deposited 11.6 +/- 0.2 Ma ago. Further geochronological evidence, derived from the Sr and C isotopic compositions of foraminifera compared with known seawater-time variations, indicates that the lower pelagic clays are early to middle Miocene, deposited at a mean rate of ~15 m/Ma.

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The glauconitic subunit contains part of the middle Miocene and probably all of the late Miocene in a condensed sequence with a very low mean depositional rate (~0.2 m/Ma). The overlying glacial marine sediments are probably Pliocene, with a high mean rate of deposition, ~45 m/Ma. This is the first application of C, O and Sr isotopic stratigraphy combined with Rb-Sr dating of glauconitic minerals, and it illustrates the applications of this integrated approach in geochronology.

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Provenance · 2 source records, 7 field assertions
SourceKeyLast seenRaw
PANGAEAoai:pangaea.de:doi:10.1594/PANGAEA.71425213 d agoJSON v1
DataCite10.1594/pangaea.71425213 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · PANGAEAconnector:pangaea@1.0.0
concepts[field].local:field:earth-environmentalmapping · PANGAEAconnector:pangaea@1.0.0
descriptionsource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/description
licensesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/rights
publication_datesource · PANGAEAconnector:pangaea@1.0.0
spatialsource · PANGAEAconnector:pangaea@1.0.0
titlesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/title