Cold climate deglaciation prior to termination 2 implied by new evidence for high sea-levels at 132 KA

Conference · Wed Jan 01 00:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5690536

Johnson, R G ^[1]

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1. Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Geology and Geophysics

Radioisotope dating of corals from reefs and beaches suggests a high sea stand just prior to termination 2. Lack of precision in the ages, stratigraphic uncertainties, and possible diagenetic alterations in the corals have prevented a widespread acceptance of this sea stand. These disadvantages can be avoided by an approach that uses differential uplift measurements to determine the duration of the interval of generally high sea-levels. The last interglacial terrace on Barbados has features indicating two intervals of constant sea-level: an older wave-cut at the inshore edge of the terrace, and a younger cut formed near present eustatic sea-level, below the crest, and just before the earliest Wisconsin glacial buildup. The differential uplift between these two features, measured at five locations having uplift rates between 0.18 and 0.39m/ka, yields a eustatic sea-level differences of 5.4m and a minimal duration of 12.1 [+-] 0.6ka between the two still stands. The assigned age of the younger wave-cut is 120 [+-] 0.5ka, based on sea-level regression due to ice sheet buildup implied by a Little Ice Age analog and rapidly falling Milankovitch summer insolation. The resulting minimal age of the first high sea-stand is 132.1 [+-] 1.1ka, about 7ka before termination 2. This age implies a major early deglaciation caused by a deficit of moisture transported to the great ice sheets, and occurring under relatively cold climate conditions.

• OSTI ID: 5690536
• Report Number(s): CONF-921058-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
BARBADOS
PALEOCLIMATOLOGY
CORALS
ISOTOPE DATING
AGE ESTIMATION
CARBON 14
COASTAL REGIONS
FLUCTUATIONS
GLACIERS
ICE CAPS
SEA LEVEL
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBON ISOTOPES
CNIDARIA
COELENTERATA
EVEN-EVEN NUCLEI
ICE
INVERTEBRATES
ISLANDS
ISOTOPES
LESSER ANTILLES
LEVELS
LIGHT NUCLEI
NUCLEI
PALEONTOLOGY
RADIOISOTOPES
VARIATIONS
WEST INDIES
YEARS LIVING RADIOISOTOPES
580000* - Geosciences