U-Series and Amino-acde Racemization Geochronology of Bermuda - Implications for Eustatic Sea-Llevel Fluctuation Over the Past 250,000 Years

Russell S. Harmon, Richard M. Mitterer, Nivat Kriausakul, Lynton S. Land, Henry P. Schwarcz, Peter Garrett, Grahame J. Larson, H. L. Vacher, Mark Rowe

Research output: Contribution to journalArticlepeer-review

Abstract

Bermuda is a stable, mid-oceanic carbonate platform for which a particularly complete record of Late Pleistocene eustatic sea-level fluctuation has been reconstructed from a detailed study of geological field relationships combined with an extensive programme of U-series and amino-acid racemization geochronology. Only twice in the past 250,000 yr. has sea level in Bermuda been above its present level, once at approximately 200 k.y. when it stood at about + 2 m and most recently at 125 ± 4 k.y. when it stood at 5 ± 1 m. These times of interglacial high sea level are characterized by the development of patch reefs and marine calcarenites at elevations above present sea level. Episodes of lower sea stand onto the Bermuda platform at elevations higher than −20 m are observed within the two interglacial periods and are characterized by the deposition of eolianites. By contrast glacial periods are times of residual soil formation and deposition of speleothems in caves at elevations below present sea level. Excellent correlation is observed between the Bermuda glacio-eustatic sea-level record and other marine and terrestrial paleoclimate records.

Original languageAmerican English
JournalPalaeogeography, Palaeoclimatology, Palaeoecology
Volume44
DOIs
StatePublished - Nov 1 1983
Externally publishedYes

Disciplines

  • Earth Sciences
  • Geology
  • Physical Sciences and Mathematics

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