Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa
Seismic profiling in the equatorial Atlantic reveals deep-water (> 4500 m) sediment bodies formed by current-controlled deposition near the intersection of large-offset fracture zones with the African margin. A 600 km-long drift accumulation, the Ivory Coast Rise, lies north of the St Paul Transf...
Main Authors: | , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
Elsevier
2006
|
Subjects: | |
Online Access: | http://discovery.ucl.ac.uk/8806/ |
id |
ftucl:oai:eprints.ucl.ac.uk.OAI2:8806 |
---|---|
record_format |
openpolar |
spelling |
ftucl:oai:eprints.ucl.ac.uk.OAI2:8806 2023-05-15T13:58:24+02:00 Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa Jones, EJ Okada, H 2006-01-01 http://discovery.ucl.ac.uk/8806/ unknown Elsevier Marine Geology , 232 pp. 49-61. (2006) Atlantic seismic reflection profiles drift deposits paleocirculation Antarctic Bottom Water fracture zones Article 2006 ftucl 2017-04-06T22:11:36Z Seismic profiling in the equatorial Atlantic reveals deep-water (> 4500 m) sediment bodies formed by current-controlled deposition near the intersection of large-offset fracture zones with the African margin. A 600 km-long drift accumulation, the Ivory Coast Rise, lies north of the St Paul Transform near 3° N. A smaller drift deposit has been identified along the northern side of the Guinea Transform at 10° N. Antarctic Bottom Water (AABW), which presently enters the eastern Atlantic basins through the Romanche and Vema Fracture Zones, probably played an important role in the development of these features. Proto-AABW may have reached the equatorial region as early as mid-Eocene time, before the establishment of permanent ice sheets in Antarctica. The Ivory Coast Rise existed as a distinct sedimentary drift by the mid-Eocene as a result of deposition from bottom water moving southwards along the African margin and westwards parallel to the St Paul Fracture Zone. This early flow pattern is in the opposite sense to the present movement of deep water in the Sierra Leone Basin. A reversal in abyssal circulation may have been caused by the northward passage of the region across the paleoequator during the Cenozoic. Article in Journal/Newspaper Antarc* Antarctic Antarctica University College London: UCL Discovery Antarctic |
institution |
Open Polar |
collection |
University College London: UCL Discovery |
op_collection_id |
ftucl |
language |
unknown |
topic |
Atlantic seismic reflection profiles drift deposits paleocirculation Antarctic Bottom Water fracture zones |
spellingShingle |
Atlantic seismic reflection profiles drift deposits paleocirculation Antarctic Bottom Water fracture zones Jones, EJ Okada, H Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa |
topic_facet |
Atlantic seismic reflection profiles drift deposits paleocirculation Antarctic Bottom Water fracture zones |
description |
Seismic profiling in the equatorial Atlantic reveals deep-water (> 4500 m) sediment bodies formed by current-controlled deposition near the intersection of large-offset fracture zones with the African margin. A 600 km-long drift accumulation, the Ivory Coast Rise, lies north of the St Paul Transform near 3° N. A smaller drift deposit has been identified along the northern side of the Guinea Transform at 10° N. Antarctic Bottom Water (AABW), which presently enters the eastern Atlantic basins through the Romanche and Vema Fracture Zones, probably played an important role in the development of these features. Proto-AABW may have reached the equatorial region as early as mid-Eocene time, before the establishment of permanent ice sheets in Antarctica. The Ivory Coast Rise existed as a distinct sedimentary drift by the mid-Eocene as a result of deposition from bottom water moving southwards along the African margin and westwards parallel to the St Paul Fracture Zone. This early flow pattern is in the opposite sense to the present movement of deep water in the Sierra Leone Basin. A reversal in abyssal circulation may have been caused by the northward passage of the region across the paleoequator during the Cenozoic. |
format |
Article in Journal/Newspaper |
author |
Jones, EJ Okada, H |
author_facet |
Jones, EJ Okada, H |
author_sort |
Jones, EJ |
title |
Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa |
title_short |
Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa |
title_full |
Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa |
title_fullStr |
Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa |
title_full_unstemmed |
Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa |
title_sort |
abyssal circulation change in the equatorial atlantic: evidence from cenozoic sedimentary drifts off west africa |
publisher |
Elsevier |
publishDate |
2006 |
url |
http://discovery.ucl.ac.uk/8806/ |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
Marine Geology , 232 pp. 49-61. (2006) |
_version_ |
1766266662251659264 |