Late Neogene sediment composition and accumulation rates of ODP Hole 120-751A
Through scanning electron microscope analysis of sediment microfabric, we 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 fro...
Main Authors: | , |
---|---|
Format: | Dataset |
Language: | English |
Published: |
PANGAEA
1992
|
Subjects: | |
Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.760173 https://doi.org/10.1594/PANGAEA.760173 |
id |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.760173 |
---|---|
record_format |
openpolar |
spelling |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.760173 2023-05-15T13:42:10+02:00 Late Neogene sediment composition and accumulation rates of ODP Hole 120-751A Rack, Frank R Palmer-Julson, Amanda LATITUDE: -57.726000 * LONGITUDE: 79.814800 * DATE/TIME START: 1988-04-18T20:00:00 * DATE/TIME END: 1988-04-19T23:30:00 1992-05-10 application/zip, 3 datasets https://doi.pangaea.de/10.1594/PANGAEA.760173 https://doi.org/10.1594/PANGAEA.760173 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.760173 https://doi.org/10.1594/PANGAEA.760173 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Rack, Frank R; Palmer-Julson, Amanda (1992): Sediment microfabric and physical properties record of late Neogene Polar Front migration, Site 751. In: Wise, SW; Schlich, R; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 120, 179-205, https://doi.org/10.2973/odp.proc.sr.120.145.1992 120-751A DRILL Drilling/drill rig Joides Resolution Leg120 Ocean Drilling Program ODP South Indian Ridge South Indian Ocean Dataset 1992 ftpangaea https://doi.org/10.1594/PANGAEA.760173 https://doi.org/10.2973/odp.proc.sr.120.145.1992 2023-01-20T07:32:10Z Through scanning electron microscope analysis of sediment microfabric, we 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. Trends in geotechnical properties with depth at Site 751 allowed us to subdivide the sedimentary column into a number of geotechnical units that reflect changes in depositional and postdepositional processes with time. Geotechnical properties are sensitive to changing sedimentary inputs of primarily siliceous and calcareous microfossils. This allows us to study the physical nature of biostratigraphically-identified hiatuses and variations in environmental conditions linked to the migration of the Polar Front across this region. The analysis of geotechnical properties permits a more detailed division of the sedimentary column than is possible from shipboard lithologic descriptions alone. Our 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 ... Dataset Antarc* Antarctic PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Indian Kerguelen ENVELOPE(79.814800,79.814800,-57.726000,-57.726000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
120-751A DRILL Drilling/drill rig Joides Resolution Leg120 Ocean Drilling Program ODP South Indian Ridge South Indian Ocean |
spellingShingle |
120-751A DRILL Drilling/drill rig Joides Resolution Leg120 Ocean Drilling Program ODP South Indian Ridge South Indian Ocean Rack, Frank R Palmer-Julson, Amanda Late Neogene sediment composition and accumulation rates of ODP Hole 120-751A |
topic_facet |
120-751A DRILL Drilling/drill rig Joides Resolution Leg120 Ocean Drilling Program ODP South Indian Ridge South Indian Ocean |
description |
Through scanning electron microscope analysis of sediment microfabric, we 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. Trends in geotechnical properties with depth at Site 751 allowed us to subdivide the sedimentary column into a number of geotechnical units that reflect changes in depositional and postdepositional processes with time. Geotechnical properties are sensitive to changing sedimentary inputs of primarily siliceous and calcareous microfossils. This allows us to study the physical nature of biostratigraphically-identified hiatuses and variations in environmental conditions linked to the migration of the Polar Front across this region. The analysis of geotechnical properties permits a more detailed division of the sedimentary column than is possible from shipboard lithologic descriptions alone. Our 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 ... |
format |
Dataset |
author |
Rack, Frank R Palmer-Julson, Amanda |
author_facet |
Rack, Frank R Palmer-Julson, Amanda |
author_sort |
Rack, Frank R |
title |
Late Neogene sediment composition and accumulation rates of ODP Hole 120-751A |
title_short |
Late Neogene sediment composition and accumulation rates of ODP Hole 120-751A |
title_full |
Late Neogene sediment composition and accumulation rates of ODP Hole 120-751A |
title_fullStr |
Late Neogene sediment composition and accumulation rates of ODP Hole 120-751A |
title_full_unstemmed |
Late Neogene sediment composition and accumulation rates of ODP Hole 120-751A |
title_sort |
late neogene sediment composition and accumulation rates of odp hole 120-751a |
publisher |
PANGAEA |
publishDate |
1992 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.760173 https://doi.org/10.1594/PANGAEA.760173 |
op_coverage |
LATITUDE: -57.726000 * LONGITUDE: 79.814800 * DATE/TIME START: 1988-04-18T20:00:00 * DATE/TIME END: 1988-04-19T23:30:00 |
long_lat |
ENVELOPE(79.814800,79.814800,-57.726000,-57.726000) |
geographic |
Antarctic Indian Kerguelen |
geographic_facet |
Antarctic Indian Kerguelen |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Supplement to: Rack, Frank R; Palmer-Julson, Amanda (1992): Sediment microfabric and physical properties record of late Neogene Polar Front migration, Site 751. In: Wise, SW; Schlich, R; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 120, 179-205, https://doi.org/10.2973/odp.proc.sr.120.145.1992 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.760173 https://doi.org/10.1594/PANGAEA.760173 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.760173 https://doi.org/10.2973/odp.proc.sr.120.145.1992 |
_version_ |
1766164057055821824 |