Paleoceanographic implications of Eocene-Oligocene calcareous nannofossils from sites 711 and 748 in the Indian Ocean

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doi: 10.2973/odp.proc.sr.120.199.1992
Author(s): Wei, Wuchang; Villa, Giuliana; Wise, Sherwood W., Jr.
Author Affiliation(s): Primary:
Fla. State Univ., Dep. Geol., Tallahassee, FL, United States
Other:
Univ. Louis Pasteur, France
Ocean Drill. Program, United States
Univ. Claude Bernard, France
Woods Hole Oceanogr. Inst., United States
Rühr Univ. Bochum, Federal Republic of Germany
Britoil, United Kingdom
Bur. Mineral Resour., Geol. and Geophys., Australia
Ohio State Univ., United States
Univ. Toronto, Canada
Univ. Nebr., United States
Brown Univ., United States
Kobe Univ., Japan
EAWANG/ETH, Switzerland
Alfred Wegener Inst. Polar and Mar. Res., Federal Republic of Germany
Tohoku Univ., United States
Univ. R.I., United States
Aust. Antarct. Div., Australia
Lamont-Doherty Geol. Obs., United States
Mass. Inst. Technol., United States
Univ. Leicester, United Kingdom
Kyoto Univ., Japan
Univ. Parma, Italy
Volume Title: Proceedings of the Ocean Drilling Program, Central Kerguelen Plateau; covering Leg 120 of the cruises of the drilling vessel JOIDES Resolution, Fremantle, Australia, to Fremantle, Australia, sites 747-751, 20 February to 30 April 1988; Part 2
Volume Author(s): Wise, Sherwood W., Jr.; Schlich, Roland; Palmer Julson, Amanda A.; Aubry, Marie-Pierre; Berggren, William A.; Bitschene, Peter Rene; Blackburn, Neal A.; Breza, James R.; Coffin, Millard F.; Harwood, David M.; Heider, Franz; Holmes, Mary Anne; Howard, William R.; Inokuchi, Hiroo; Kelts, Kerry; Lazarus, David B.; Mackensen, Andreas; Maruyama, Toshiaki; Munschy, Marc; Pratson, Elizabeth Lewis; Quilty, Patrick G.; Rack, Frank R.; Salters, Vincent J. M.; Sevigny, James H.; Storey, Michael; Takemura, Atsushi; Watkins, David K.; Whitechurch, Hubert; Zachos, James; Barbu, Eva M.
Source: Proceedings of the Ocean Drilling Program, Central Kerguelen Plateau; covering Leg 120 of the cruises of the drilling vessel JOIDES Resolution, Fremantle, Australia, to Fremantle, Australia, sites 747-751, 20 February to 30 April 1988; Part 2, Sherwood W. Wise, Jr., Roland Schlich, Amanda A. Palmer Julson, Marie-Pierre Aubry, William A. Berggren, Peter Rene Bitschene, Neal A. Blackburn, James R. Breza, Millard F. Coffin, David M. Harwood, Franz Heider, Mary Anne Holmes, William R. Howard, Hiroo Inokuchi, Kerry Kelts, David B. Lazarus, Andreas Mackensen, Toshiaki Maruyama, Marc Munschy, Elizabeth Lewis Pratson, Patrick G. Quilty, Frank R. Rack, Vincent J. M. Salters, James H. Sevigny, Michael Storey, Atsushi Takemura, David K. Watkins, Hubert Whitechurch, James Zachos and Eva M. Barbu. Proceedings of the Ocean Drilling Program, Scientific Results, Vol.120, p.979-999. Publisher: Texas A & M University, Ocean Drilling Program, College Station, TX, United States. ISSN: 0884-5891
Note: In English. 101 refs.; illus. incl. 4 tables, sketch map
Summary: An Eocene-Oligocene calcareous nannofossil biostratigraphic framework for ODP Site 748 in the southern Indian Ocean is established, which provides a foundation for this and future quantitative biogeographic studies. This biostratigraphic analysis, together with quantitative nannofossil data, enables a reinterpretation of the preliminary magnetostratigraphy and a new placement for magnetic Subchron C13N in the lowermost Oligocene. Calcareous nannofossil species diversity is low at Site 748 relative to lower latitude sites, with about 13 taxa in the Middle Eocene, gradually decreasing to about 6 in the Late Oligocene. There is, however, no apparent mass extinction at any stratigraphic level. Similarly, no mass extinctions were recorded at or near the Eocene/Oligocene boundary at Site 711 in the equatorial Indian Ocean. Species diversity at the equatorial site is significantly higher than at Site 748, with a maximum of 39 species in the Middle Eocene and a minimum of 14 species in the Late Oligocene. The abundance patterns of nannofossil taxa are also quite different at the two sites. An abrupt increase in the abundance of cool-water taxa (from about 20 to over 90%) occurred from 36.3 to 35.9 Ma at high-latitude Site 748. Coincident with this event was a 1.0 per mill positive shift in the delta18O value of planktonic foraminifers and the occurrence of ice-rafted debris. (Auth. mod.)
Year of Publication: 1992
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 09 Paleontology, Paleobotany; Algae; Biostratigraphy; Cenozoic; Eocene; Indian Ocean; Kerguelen Plateau; Leg 115; Leg 120; Microfossils; Nannofossils; Neogene; ODP Site 711; ODP Site 748; Ocean Drilling Program; Paleo-oceanography; Paleogene; Plantae; Stratigraphy; Tertiary; Thallophytes
Coordinates: S024434 S024433 E0610947 E0610946
S582627 S582627 E0785854 E0785853
Record ID: 1992037062
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from the Antarctic Bibliography, United States