Sediment microfabric and physical properties record of late Neogene polar front migration, Site 751

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doi: 10.2973/odp.proc.sr.120.145.1992
Author(s): Rack, Frank R.; Palmer Julson, Amanda A.
Author Affiliation(s): Primary:
Ocean Drilling Program, College Station, TX, United States
Other:
Univ. Louis Pasteur, France
Ocean Drilling 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. Nebraska, United States
Brown Univ., United States
Kobe Univ., Japan
EAWAG/ETH, Switzerland
Alfred Wegener Inst. Polar and Mar. Res., Federal Republic of Germany
Tohoku Univ., United States
Lamont-Doherty Geol. Obs., United States
Australian Antarctic Division, Australia
Massachusetts Institute of Technology, United States
Univ. Leicester, United Kingdom
Kyoto Univ., Japan
Univ. R. I., United States
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 1
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; 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 1, 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 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.179-205. Publisher: Texas A & M University, Ocean Drilling Program, College Station, TX, United States. ISSN: 0884-5891
Note: In English. 52 refs.; illus. incl. 3 tables, 5 plates, sketch map
Summary: Through scanning electron microscope analysis of sediment microfabric, the authors have evaluated variations in high-resolution shipboard physical properties (index properties and shear strength), sediment components (smear slide determinations), and shore-based calcium carbonate and biogenic silica data from Site 751 (Kerguelen Plateau). The stratigraphic section at this site records a change in biogenic ooze composition from predominantly calcareous (nannofossil) to siliceous (diatom) ooze from 23 Ma to the present, reflecting expansion of antarctic water masses during the Late Neogene. The profound change in physical properties and sediment character at 40.1 mbsf (5-6 Ma) evidently records the northward movement of the Polar Front and a change in absolute accumulation rates of sediment at this site. The study of the sedimentary microfabric indicates that randomly oriented, elongate pennate diatom valves compose the sediments with highest porosity and water content values, and the lowest density values (wet bulk, dry bulk, and grain density). Conversely, sediments composed of nannofossils and disassociated nannofossil crystallites and little or no siliceous remains have the lowest porosity and water content values, and the highest density values. Samples of mixed siliceous/calcareous composition have intermediate physical property values, but these vary according to the nature of the sedimentary matrix and the state of preservation of individual skeletal elements. (Auth. mod.)
Year of Publication: 1992
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Biogenic processes; Cenozoic; Clastic sediments; Diatoms; Fabric; Indian Ocean; Kerguelen Plateau; Leg 120; Microfossils; Movement; Nannofossils; Neogene; ODP Site 751; Ocean Drilling Program; Ooze; Paleoenvironment; Physical properties; Plantae; Properties; Sediments; Stratigraphy; Tertiary; Textures; Thallophytes
Coordinates: S574334 S574334 E0794853 E0794853
Record ID: 1992037349
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from the Antarctic Bibliography, United States