Journal ArticleDOI
Oxygen isotopic evidence for the development of the psychrosphere 38 Myr ago
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In this article, a deep-sea palaeo-temperature record has been established for the past 54 Myr based on DSDP sites in the sub-Antarctic; detailed arguments give evidence that the Antarctic ice sheet developed during the Middle Miocene.Abstract:
THREE major elements were involved in the evolution of oceanic circulation during the Cainozoic. The first of these was the diminishing role of oceanic meridional circulation in equatorial areas, the second was the development of circum-Antarctic circulation and the third involves the development of the present-day system of bottom waters of the world ocean, the ‘psychrosphere’1,2. Because deep bottom waters are mostly derived from the polar regions, their characteristics, such as temperature, reflect surface conditions at high latitudes3. Past temperature changes of deep oceanic waters, and thus of polar surface waters, can be determined from the oxygen isotopic composition of deep-dwelling benthonic microfossils3,4. A deep-sea palaeo-temperature record has been established4 for the past 54 Myr based on DSDP sites in the sub-Antarctic; detailed arguments4 give evidence that the Antarctic ice sheet developed during the Middle Miocene. Previous to this, however, a significant 5 °C decline in bottom-water temperature is recorded close to the Eocene–Oligocene boundary and is considered4 to represent the onset of Antarctic bottom-water formation at temperatures close to freezing. This heralds the beginning of the modern thermo-haline circulation and is thus one of the most important palaeo-oceanographic events in the Cainozoic. We examine here in more detail the palaeotemperature event near the Eocene-Oligocene boundary, the latter having an age of 38 Myr (ref. 5).read more
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Abrupt deep-sea warming, palaeoceanographic changes and benthic extinctions at the end of the Palaeocene
James P. Kennett,Lowell D. Stott +1 more
TL;DR: A remarkable oxygen and carbon isotope excursion occurred in Antarctic waters near the end of the Palaeocene (~57.33 Myr ago), indicating rapid global warming and oceanographic changes that caused one of the largest deep-sea benthic extinctions of the past 90 million years.
Journal ArticleDOI
Cenozoic evolution of Antarctic glaciation the Circum-Antarctic Ocean and their impact on global paleoceanography
TL;DR: Deep-sea drilling in the Antarctic region (Deep-Sea Drilling Project legs 28, 29, 35, and 36) has provided many new data about the development of circum-Antarctic circulation and closely related glacial evolution of Antarctica as discussed by the authors.
Journal ArticleDOI
Tertiary oxygen isotope synthesis, sea level history, and continental margin erosion
TL;DR: Tertiary benthic and planktonic foraminiferal oxygen isotope records are correlated to a standard geomagnetic polarity time scale, making use of improved chronostratigraphic control and additional Oligocene isotope data as discussed by the authors.
Journal ArticleDOI
Unlocking the Ice House: Oligocene‐Miocene oxygen isotopes, eustasy, and margin erosion
TL;DR: In this article, the authors improved Oligocene to Miocene correlations of δ18O records and erected eight oxygen isotope zones (Oi1-Oi2, Mi1-Mi6).
Journal ArticleDOI
Cenozoic deep-sea temperatures and global ice volumes from Mg/Ca in benthic foraminiferal calcite
TL;DR: A deep-sea temperature record for the past 50 million years has been produced from the magnesium/calcium ratio (Mg/Ca) in benthic foraminiferal calcite as discussed by the authors.
References
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Journal ArticleDOI
Tertiary marine paleotemperatures
TL;DR: Oxygen isotopic compositions of the tests of planktonic foraminifera from several Deep Sea Drilling Project sites provide a general picture of low-latitude marine temperatures from Maastrichtian time to the present.
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A Cenozoic time‐scale — some implications for regional geology and paleobiogeography
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The origin of the psychrosphere as recorded in changes of deep-sea ostracode assemblages
TL;DR: In this paper, the Deep Sea Drilling Project (DSDP) collected 425 core samples from 77 sites of the first 14 Legs of its survey of the world ocean floor and analyzed 80 species from 27 composite planktic-foraminiferal time zones representing the last 75 million years of deep-sea faunal development.