Liu Zhifei et al. (2004): Deep-water earliest Oligocene glacial maximum (EOGM) in South Atlantic

Leg/Site/Hole:
ODP 208
ODP 208 1262
ODP 208 1265
Identifier:
2005-045586
georefid

10.1360/04wd0228
doi

Creator:
Liu Zhifei
Tongji University, Laboratory of Marine Geology, Shanghai, China
author

Tuo Shouting
author

Zhao Quanhong
author

Cheng Xinrong
author

Huang Wei
author

Identification:
Deep-water earliest Oligocene glacial maximum (EOGM) in South Atlantic
2004
Chinese Science Bulletin
Science Press, Beijing, China
49
20
2190-2197
The most prominent cooling event of the Earth surface during Cenozoic in the long-term transition from a non-glaciated planet, or "green-house world", to a polar, glaciated planet, or "ice-house world", is the Earliest Oligocene Glacial Maximum (EOGM) above the Eocene/Oligocene boundary at about 33.7 Ma. Planktonic and benthic foraminiferal oxygen and carbon isotopes, carbonate content, and coarse fraction, along with high-resolution color reflectance and magnetic susceptibility records during 35-30 Ma, from deep-water Sites 1262 and 1265, Ocean Drilling Program (ODP) Leg 208 in South Atlantic, reveal the global cooling event occurring in both surface and deep oceans. The results show that the earliest Oligocene delta (super 18) O values during 33.5-33.1 Ma represent the magnitude of continental ice sheets on east Antarctica and indicate the large decrease in both surface and deep water temperatures of worldwide oceans. The delta (super 13) C records show the large excursion during the period of EOGM event and indicate some types of shift in global carbon reservoir, probably demonstrating the sudden increase in organic carbon burial rates and the changes in the distribution and timing of production. At the same time, lithologic composition, carbonate content, color reflectance, and coarse fraction brought about significant changes close to the Eocene/Oligocene boundary, reflecting the abrupt deepening in the carbonate compensation depth (CCD). Changes in carbonate content were revealed from the color reflectance identify periodicities associated with eccentricity of the Earth's orbit (100 and 400 ka), further indicating orbitally forced global climate variations in the Early Oligocene.
English
Serial
Coverage:Geographic coordinates:
North:-20.0000
West:-5.0000East: 5.0000
South:-30.0000

Stratigraphy; ancient ice ages; Atlantic Ocean; bathymetry; bottom features; C-13/C-12; carbon; Cenozoic; climate change; deep-water environment; depositional environment; dissolved materials; Eocene; Foraminifera; high-resolution methods; Invertebrata; isotope ratios; isotopes; last glacial maximum; Leg 208; magnetic properties; magnetic susceptibility; marine environment; microfossils; O-18/O-16; Ocean Drilling Program; ocean floors; ODP Site 1262; ODP Site 1265; Oligocene; oxygen; paleoclimatology; Paleogene; paleomagnetism; planktonic taxa; Protista; reflectance; South Atlantic; stable isotopes; stratigraphic boundary; Tertiary; Walvis Ridge;

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