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Stable isotope composition and ice rafted debris in early Late Pliocene sediments from Maud Rise, South Atlantic

Listed in PANGAEA and DataCite — shown once because both records carry DOI 10.1594/pangaea.681724

We have conducted an integrated study of ice-rafted debris (IRD) and oxygen isotopes (measured on Cibicides, Globigerina bulloides, and Neogloboquadrina pachyderma, using identical samples).

Description

We used samples from the early Late Pliocene Gauss Chron from ODP Site 114-704 on the Meteor Rise in the subantarctic South Atlantic. During the early Gauss Chron, the oxygen isotopic ratios are generally up to 0.5‰-0.6‰ less than their respective Holocene values.

The lowest values in this record can accommodate a warming of about 2.5°C or a sea-level rise of about 50 m, but not both, and probably result from some warming and a small reduction in global ice volume. Starting with isotope stage MG2 [ 3.23 Ma on the Berggren et al. ( 1985) time scale; 3.38 on the Shackleton et al. ( 1995b) time scale] oxygen-isotopic values generally increase (and oscillate about a Holocene mean). The first significant IRD appears at the same time.

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There is a subsequent increase in IRD amounts upsection. In order to reach the site, this material must have been transported by large, tabular icebergs derived from Antarctic ice shelves or ice tongues, similar to occasional, large modern icebergs. This combined record suggests strongly that the Antarctic ice sheet was essentially intact; some warming at the drill site is indicated, but not a major reduction in ice-volume on Antarctica.

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Inferred from text
Isotope geochemistry 76% · Tabular 75%
Provenance · 2 source records, 9 field assertions
SourceKeyLast seenRaw
PANGAEAoai:pangaea.de:doi:10.1594/PANGAEA.68172412 d agoJSON v1
DataCite10.1594/pangaea.68172412 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · PANGAEAconnector:pangaea@1.0.0
concepts[field].anzsrc:field:370303enrichment · DataCitetaxonomy-embedding@1.1.0title+keywords+description (76%)
concepts[field].local:field:earth-environmentalmapping · PANGAEAconnector:pangaea@1.0.0
concepts[modality].local:modality:tabularenrichment · PANGAEAkeyword-concept-rules@1.0.0title+description (75%)
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titlesource · PANGAEAconnector:pangaea@1.0.0/metadata/dc/title