Siliceous components of Pliocene-Holocene sediments of the South Atlantic
The Pliocene-Holocene sediments recovered on ODP Leg 114 from Holes 699A, 701C, and 704B are the subject of a detailed investigation to interpret changes in the Oceanographic environment of the South Atlantic in the vicinity of the Polar Front Zone (PFZ). The cores sample sediments at shallow (Hole...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.754904 2023-05-15T13:42:10+02:00 Siliceous components of Pliocene-Holocene sediments of the South Atlantic Westall, Francis Fenner, Juliane M MEDIAN LATITUDE: -50.469000 * MEDIAN LONGITUDE: -15.489400 * SOUTH-BOUND LATITUDE: -52.985000 * WEST-BOUND LONGITUDE: -30.677000 * NORTH-BOUND LATITUDE: -46.880000 * EAST-BOUND LONGITUDE: 7.420500 * DATE/TIME START: 1987-03-20T10:45:00 * DATE/TIME END: 1987-05-03T10:14:00 1991-12-09 application/zip, 12 datasets https://doi.pangaea.de/10.1594/PANGAEA.754904 https://doi.org/10.1594/PANGAEA.754904 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.754904 https://doi.org/10.1594/PANGAEA.754904 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Westall, Francis; Fenner, Juliane M (1991): Pliocene-Holocene polar front zone in the South Atlantic: changes in its position and sediment-accumulation rates from Holes 699A, 701C, and 704B (synthesis). In: Ciesielski, PF; Kristoffersen, Y; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 114, 609-646, https://doi.org/10.2973/odp.proc.sr.114.175.1991 114-699A 114-701C 114-704B DRILL Drilling/drill rig Joides Resolution Leg114 Ocean Drilling Program ODP South Atlantic Ocean Dataset 1991 ftpangaea https://doi.org/10.1594/PANGAEA.754904 https://doi.org/10.2973/odp.proc.sr.114.175.1991 2023-01-20T07:31:59Z The Pliocene-Holocene sediments recovered on ODP Leg 114 from Holes 699A, 701C, and 704B are the subject of a detailed investigation to interpret changes in the Oceanographic environment of the South Atlantic in the vicinity of the Polar Front Zone (PFZ). The cores sample sediments at shallow (Hole 704B, 2532 m), intermediate (Hole 699A, 3716 m), and basinal (Hole 701C, 4647 m) depths. Sites 699 and 704 come under the influence of the Antarctic Circumpolar Current (ACC) and Circumpolar Deep Water. It is possible that the upper reaches of Antarctic Bottom Water (AABW) may also affect Hole 699A. Site 701 is influenced by AABW. Closely spaced samples were analyzed for grain-size distribution, sand fraction components, biosiliceous microfossils, organic carbon, and water content. PFZ migrations are traced using changes in bulk sedimentaccumulation rates and the abundance of the diatoms Actiniscus ssp. and Genus et species indet. 1 Fenner (1991), as well as changes in sediment grain size and composition. Diatomaceous sediments of Gilbert age in Hole 699A indicate that the PFZ was positioned over this site, but during the Gauss it migrated north, bringing in less productive Antarctic Surface Water. All cores document a very gradual southerly movement of the PFZ throughout the Matuyama (with some sharp fluctuations of the northen PFZ border over Site 704 between 1.45 and 1.83 m.y.). This regressive shift culminated in the late Matuyama. The latest Matuyama to earliest Brunhes record in Hole 699A has been removed by a hiatus lasting from 1.0 to 0.6 m.y., which was probably caused by intensification of the deep-reaching ACC. The corresponding interval in Hole 704B, the shallowest core, contains evidence of winnowing. Sharp fluctuations of large amplitude and high frequency in the lithology of the sediments from Hole 704B in the eastern South Atlantic, starting at about 0.75 m.y. and characterizing the whole Brunhes Epoch, record the rapid movement of the northern border of the PFZ over the site. These reflect strong ... Dataset Antarc* Antarctic South Atlantic Ocean PANGAEA - Data Publisher for Earth & Environmental Science Antarctic The Antarctic ENVELOPE(-30.677000,7.420500,-46.880000,-52.985000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
114-699A 114-701C 114-704B DRILL Drilling/drill rig Joides Resolution Leg114 Ocean Drilling Program ODP South Atlantic Ocean |
spellingShingle |
114-699A 114-701C 114-704B DRILL Drilling/drill rig Joides Resolution Leg114 Ocean Drilling Program ODP South Atlantic Ocean Westall, Francis Fenner, Juliane M Siliceous components of Pliocene-Holocene sediments of the South Atlantic |
topic_facet |
114-699A 114-701C 114-704B DRILL Drilling/drill rig Joides Resolution Leg114 Ocean Drilling Program ODP South Atlantic Ocean |
description |
The Pliocene-Holocene sediments recovered on ODP Leg 114 from Holes 699A, 701C, and 704B are the subject of a detailed investigation to interpret changes in the Oceanographic environment of the South Atlantic in the vicinity of the Polar Front Zone (PFZ). The cores sample sediments at shallow (Hole 704B, 2532 m), intermediate (Hole 699A, 3716 m), and basinal (Hole 701C, 4647 m) depths. Sites 699 and 704 come under the influence of the Antarctic Circumpolar Current (ACC) and Circumpolar Deep Water. It is possible that the upper reaches of Antarctic Bottom Water (AABW) may also affect Hole 699A. Site 701 is influenced by AABW. Closely spaced samples were analyzed for grain-size distribution, sand fraction components, biosiliceous microfossils, organic carbon, and water content. PFZ migrations are traced using changes in bulk sedimentaccumulation rates and the abundance of the diatoms Actiniscus ssp. and Genus et species indet. 1 Fenner (1991), as well as changes in sediment grain size and composition. Diatomaceous sediments of Gilbert age in Hole 699A indicate that the PFZ was positioned over this site, but during the Gauss it migrated north, bringing in less productive Antarctic Surface Water. All cores document a very gradual southerly movement of the PFZ throughout the Matuyama (with some sharp fluctuations of the northen PFZ border over Site 704 between 1.45 and 1.83 m.y.). This regressive shift culminated in the late Matuyama. The latest Matuyama to earliest Brunhes record in Hole 699A has been removed by a hiatus lasting from 1.0 to 0.6 m.y., which was probably caused by intensification of the deep-reaching ACC. The corresponding interval in Hole 704B, the shallowest core, contains evidence of winnowing. Sharp fluctuations of large amplitude and high frequency in the lithology of the sediments from Hole 704B in the eastern South Atlantic, starting at about 0.75 m.y. and characterizing the whole Brunhes Epoch, record the rapid movement of the northern border of the PFZ over the site. These reflect strong ... |
format |
Dataset |
author |
Westall, Francis Fenner, Juliane M |
author_facet |
Westall, Francis Fenner, Juliane M |
author_sort |
Westall, Francis |
title |
Siliceous components of Pliocene-Holocene sediments of the South Atlantic |
title_short |
Siliceous components of Pliocene-Holocene sediments of the South Atlantic |
title_full |
Siliceous components of Pliocene-Holocene sediments of the South Atlantic |
title_fullStr |
Siliceous components of Pliocene-Holocene sediments of the South Atlantic |
title_full_unstemmed |
Siliceous components of Pliocene-Holocene sediments of the South Atlantic |
title_sort |
siliceous components of pliocene-holocene sediments of the south atlantic |
publisher |
PANGAEA |
publishDate |
1991 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.754904 https://doi.org/10.1594/PANGAEA.754904 |
op_coverage |
MEDIAN LATITUDE: -50.469000 * MEDIAN LONGITUDE: -15.489400 * SOUTH-BOUND LATITUDE: -52.985000 * WEST-BOUND LONGITUDE: -30.677000 * NORTH-BOUND LATITUDE: -46.880000 * EAST-BOUND LONGITUDE: 7.420500 * DATE/TIME START: 1987-03-20T10:45:00 * DATE/TIME END: 1987-05-03T10:14:00 |
long_lat |
ENVELOPE(-30.677000,7.420500,-46.880000,-52.985000) |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic South Atlantic Ocean |
genre_facet |
Antarc* Antarctic South Atlantic Ocean |
op_source |
Supplement to: Westall, Francis; Fenner, Juliane M (1991): Pliocene-Holocene polar front zone in the South Atlantic: changes in its position and sediment-accumulation rates from Holes 699A, 701C, and 704B (synthesis). In: Ciesielski, PF; Kristoffersen, Y; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 114, 609-646, https://doi.org/10.2973/odp.proc.sr.114.175.1991 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.754904 https://doi.org/10.1594/PANGAEA.754904 |
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.754904 https://doi.org/10.2973/odp.proc.sr.114.175.1991 |
_version_ |
1766163937091387392 |