Tentative correlation of midcontinent glacial sequence with marine chronology

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6653642

Dube, T E

A tentative glacial-interglacial 3-million-year chronology is synthesized by regional correlation of Midcontinent tills and paleosols to marine paleotemperature/eustatic cycles and oxygen isotope stages. The paleotemperature curves of Beard et al. (1982), based on planktonic foraminiferal abundances, correspond directly with eustatic cycles during the last 3 Ma. These generalized curves are shown to correlate reasonably well with standard oxygen isotope stages at least for the past 900 ka. This indicates that paleotemperature and Vail-type eustatic cycles have been glacially induced during the last 3 Ma. The chronology developed here utilizes both paleotemperature and oxygen isotope stages; however, below the Jaramillo magnetic subchron, isotope curves are more variable and only paleotemperature stages are used. Tills and paleosols at type localities in the Midcontinent area of the US are correlated to the SPECMAP oxygen isotope time scale. Because mid-Brunhes events are poorly constrained by radiometric dates, alternative correlations are possible. The oldest known Midcontinent tills correlate to the first Plio-Pleistocene cold paleotemperature stage and drop in sea level at 2.4 Ma. This Late Pliocene event also corresponds to the first major isotopic enrichment and the onset of late Cenozoic ice-rafting in the North Atlantic region.

• Research Organization: Univ. of Washington, Seattle (USA)
• OSTI ID: 6653642
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
580400 -- Geochemistry-- (-1989)
AGE ESTIMATION
ANIMALS
AQUATIC ORGANISMS
CENOZOIC ERA
CHEMISTRY
CORRELATIONS
DEPOSITION
FEDERAL REGION VIII
FORAMINIFERA
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GLACIERS
INVERTEBRATES
ISOTOPE RATIO
ISOTOPES
MICROORGANISMS
MORAINES
NORTH AMERICA
OXYGEN ISOTOPES
PALEOCLIMATOLOGY
PALEONTOLOGY
PALEOTEMPERATURE
PLANKTON
PROTOZOA
SARCODINA
SEDIMENTATION
SEDIMENTS
SOILS
USA