PLEISTOCENE EVOLUTION: NORTHERN HEMISPHERE ICE SHEETS AND NORTH ATLANTIC OCEAN

被引:642
作者
Ruddiman, W. F. [1 ]
Raymo, M. E. [1 ]
Martinson, D. G. [1 ]
Clement, B. M. [2 ]
Backman, J. [3 ]
机构
[1] Columbia Univ, Lamont Doherty Geol Observ, Palisades, NY 10964 USA
[2] Texas A&M Univ, Ocean Drilling Program, College Stn, TX USA
[3] Univ Stockholm, Dept Geol, S-10691 Stockholm, Sweden
来源
PALEOCEANOGRAPHY | 1989年 / 4卷 / 04期
基金
美国国家科学基金会;
关键词
D O I
10.1029/PA004i004p00353
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
We analyze five high-resolution time series spanning the last 1.65 m.y.: benthic foraminiferal delta O-18 and delta C-13, percent CaCO3, and estimated sea surface temperature (SST) at North Atlantic Deep Sea Drilling Project site 607 and percent CaCO3 at site 609. Each record is a multicore composite verified for continuity by splicing among multiple holes. These climatic indices portray changes in northern hemisphere ice sheet size and in North Atlantic surface and deep circulation. By tuning obliquity and precession component in the delta O-18 record to orbital variations, we have devised a time scale (TP607) for the entire Pleistocene that agrees in age with all K/Ar-dated magnetic reversals to within 1.5%. The Brunhes time scale is taken from Imbrie et al. [1984], except for differences near the stage 17/16 transition (0.70 to 0.64 Ma). All indicators show a similar evolution from the Matuyama to the Brunhes chrons: orbital eccentricity and precession responses increased in amplitude; those at orbital obliquity decreased The change in dominance from obliquity to eccentricity occurred over several hundred thousand years, with fastest changes around 0.7 to 0.6 Ma. The coherent, in-phase responses of delta O-18, delta C-13, CaCO3 and SST at these rhythms indicate that northern hemisphere ice volume changes have controlled most of the North Atlantic surface-ocean and deep-ocean responses for the last 1.6 m.y. The delta C-13, percent CaCo3, and SST records at site 607 also show prominent changes at low frequencies, including a prominent long-wavelength oscillation toward glacial conditions that is centered between 0.9 and 0.6 Ma. These changes appear to be associated neither with orbital forcing nor with changes in ice volume.
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页码:353 / 412
页数:60
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