Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean
The upper Miocene to Pleistocene sediments recovered at ODP Sites 745 and 746 in the Australian-Antarctic Basin are characterized by cyclic facies changes. Sedimentological investigations of a detailed Quaternary section reveal that facies A is dominated by a high content of siliceous microfossils,...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.587844 2024-09-15T17:46:35+00:00 Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean Ehrmann, Werner Grobe, Hannes LATITUDE: -59.595000 * LONGITUDE: 85.854200 * DATE/TIME START: 1988-02-09T15:30:00 * DATE/TIME END: 1988-02-10T17:15:00 1991 application/zip, 5 datasets https://doi.pangaea.de/10.1594/PANGAEA.587844 https://doi.org/10.1594/PANGAEA.587844 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.587844 https://doi.org/10.1594/PANGAEA.587844 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess Supplement to: Ehrmann, Werner; Grobe, Hannes (1991): Cyclic sedimentation at sites 745 and 746. In: Barron, J; Larsen, B; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 119, 225-237, https://doi.org/10.2973/odp.proc.sr.119.123.1991 119-745B DRILL Drilling/drill rig Indian Ocean Joides Resolution Leg119 Ocean Drilling Program ODP dataset publication series 1991 ftpangaea https://doi.org/10.1594/PANGAEA.58784410.2973/odp.proc.sr.119.123.1991 2024-07-24T02:31:42Z The upper Miocene to Pleistocene sediments recovered at ODP Sites 745 and 746 in the Australian-Antarctic Basin are characterized by cyclic facies changes. Sedimentological investigations of a detailed Quaternary section reveal that facies A is dominated by a high content of siliceous microfossils, a relatively low terrigenous sediment content, an ice-rafted component, low concentrations of fine sediment particles, and a relatively high smectite content. This facies corresponds to interglacial sedimentary conditions. Facies B, in contrast, is characteristic of glacial conditions and is dominated by a large amount of terrigenous material and a smaller opaline component. There is also a prominent ice-rafted component. The microfossils commonly are reworked and broken. The clay mineral assemblages show higher proportions of glacially derived illite and chlorite. A combination of four different processes, attributed to glacial-interglacial cycles, was responsible for the cyclic facies changes during Quaternary time: transport by gravity, ice, and current and changes in primary productivity. Of great importance was the movement of the grounding line of the ice shelves, which directly influenced the intensity of ice rafting and of gravitational sediment transport to the deep sea. The extension of the ice shelves was also responsible for the generation of cold and erosive Antarctic Bottom Water, which controlled the grain-size distribution, particularly of the fine fraction, in the investigated area. Other/Unknown Material Antarc* Antarctic Ice Shelves Southern Ocean PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(85.854200,85.854200,-59.595000,-59.595000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
119-745B DRILL Drilling/drill rig Indian Ocean Joides Resolution Leg119 Ocean Drilling Program ODP |
spellingShingle |
119-745B DRILL Drilling/drill rig Indian Ocean Joides Resolution Leg119 Ocean Drilling Program ODP Ehrmann, Werner Grobe, Hannes Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean |
topic_facet |
119-745B DRILL Drilling/drill rig Indian Ocean Joides Resolution Leg119 Ocean Drilling Program ODP |
description |
The upper Miocene to Pleistocene sediments recovered at ODP Sites 745 and 746 in the Australian-Antarctic Basin are characterized by cyclic facies changes. Sedimentological investigations of a detailed Quaternary section reveal that facies A is dominated by a high content of siliceous microfossils, a relatively low terrigenous sediment content, an ice-rafted component, low concentrations of fine sediment particles, and a relatively high smectite content. This facies corresponds to interglacial sedimentary conditions. Facies B, in contrast, is characteristic of glacial conditions and is dominated by a large amount of terrigenous material and a smaller opaline component. There is also a prominent ice-rafted component. The microfossils commonly are reworked and broken. The clay mineral assemblages show higher proportions of glacially derived illite and chlorite. A combination of four different processes, attributed to glacial-interglacial cycles, was responsible for the cyclic facies changes during Quaternary time: transport by gravity, ice, and current and changes in primary productivity. Of great importance was the movement of the grounding line of the ice shelves, which directly influenced the intensity of ice rafting and of gravitational sediment transport to the deep sea. The extension of the ice shelves was also responsible for the generation of cold and erosive Antarctic Bottom Water, which controlled the grain-size distribution, particularly of the fine fraction, in the investigated area. |
format |
Other/Unknown Material |
author |
Ehrmann, Werner Grobe, Hannes |
author_facet |
Ehrmann, Werner Grobe, Hannes |
author_sort |
Ehrmann, Werner |
title |
Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean |
title_short |
Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean |
title_full |
Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean |
title_fullStr |
Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean |
title_full_unstemmed |
Mineralogical and grain size analysis of ODP Hole 119-745B from the Southern Ocean |
title_sort |
mineralogical and grain size analysis of odp hole 119-745b from the southern ocean |
publisher |
PANGAEA |
publishDate |
1991 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.587844 https://doi.org/10.1594/PANGAEA.587844 |
op_coverage |
LATITUDE: -59.595000 * LONGITUDE: 85.854200 * DATE/TIME START: 1988-02-09T15:30:00 * DATE/TIME END: 1988-02-10T17:15:00 |
long_lat |
ENVELOPE(85.854200,85.854200,-59.595000,-59.595000) |
genre |
Antarc* Antarctic Ice Shelves Southern Ocean |
genre_facet |
Antarc* Antarctic Ice Shelves Southern Ocean |
op_source |
Supplement to: Ehrmann, Werner; Grobe, Hannes (1991): Cyclic sedimentation at sites 745 and 746. In: Barron, J; Larsen, B; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 119, 225-237, https://doi.org/10.2973/odp.proc.sr.119.123.1991 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.587844 https://doi.org/10.1594/PANGAEA.587844 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1594/PANGAEA.58784410.2973/odp.proc.sr.119.123.1991 |
_version_ |
1810494859771904000 |