Late Cretaceous benthic foraminiferal assemblages from Demerara Rise, western tropical Atlantic
This paper is based on Santonian–Campanian sediments of Ocean Drilling Program Sites 1257 (2951 mbsl) and 1259 (2353 mbsl) from Demerara Rise (Leg 207, western tropical Atlantic, off Surinam). According to its position, Demerara Rise should have been influenced by the early opening of the Equatorial...
Main Authors: | , |
---|---|
Format: | Dataset |
Language: | English |
Published: |
PANGAEA
2006
|
Subjects: | |
Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.746960 https://doi.org/10.1594/PANGAEA.746960 |
id |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.746960 |
---|---|
record_format |
openpolar |
spelling |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.746960 2023-05-15T17:36:39+02:00 Late Cretaceous benthic foraminiferal assemblages from Demerara Rise, western tropical Atlantic Friedrich, Oliver Erbacher, Jochen MEDIAN LATITUDE: 9.377215 * MEDIAN LONGITUDE: -54.270620 * SOUTH-BOUND LATITUDE: 9.300400 * WEST-BOUND LONGITUDE: -54.341960 * NORTH-BOUND LATITUDE: 9.453830 * EAST-BOUND LONGITUDE: -54.199080 * DATE/TIME START: 2003-01-15T14:30:00 * DATE/TIME END: 2003-02-16T13:15:00 2006-10-25 application/zip, 2 datasets https://doi.pangaea.de/10.1594/PANGAEA.746960 https://doi.org/10.1594/PANGAEA.746960 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.746960 https://doi.org/10.1594/PANGAEA.746960 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Friedrich, Oliver; Erbacher, Jochen (2006): Benthic foraminiferal assemblages from Demerara Rise (ODP Leg 207, western tropical Atlantic): possible evidence for a progressive opening of the Equatorial Atlantic Gateway. Cretaceous Research, 27(3), 377-397, https://doi.org/10.1016/j.cretres.2005.07.006 207-1257A 207-1259B 207-1259C DRILL Drilling/drill rig Joides Resolution Leg207 North Atlantic Ocean Ocean Drilling Program ODP Dataset 2006 ftpangaea https://doi.org/10.1594/PANGAEA.746960 https://doi.org/10.1016/j.cretres.2005.07.006 2023-01-20T07:31:57Z This paper is based on Santonian–Campanian sediments of Ocean Drilling Program Sites 1257 (2951 mbsl) and 1259 (2353 mbsl) from Demerara Rise (Leg 207, western tropical Atlantic, off Surinam). According to its position, Demerara Rise should have been influenced by the early opening of the Equatorial Atlantic Gateway and the establishment of a bottom-water connection between the central and South Atlantic Oceans during the Late Cretaceous. The investigated benthic foraminiferal faunas demonstrate strong fluctuations in bottom-water oxygenation and organic-matter flux to the sea-floor. The Santonian–earliest Campanian interval is characterised by laminated black shales without benthic foraminifera in the lowermost part, followed by an increasing number of benthic foraminifera. These are indicative of anoxic to dysoxic bottom waters, high organic-matter fluxes and a position within the oxygen minimum zone. At the shallower Site 1259, benthic foraminifera occurred earlier (Santonian) than at the deeper Site 1257 (Early Campanian). This suggests that the shallower site was characterised by fluctuations in the oxygen minimum zone and that a re-oxygenation of the sea-floor started considerably earlier at shallower water-depths. We speculate that this re-oxygenation was related to the ongoing opening of the Equatorial Atlantic Gateway. A condensed glauconitic chalk interval of Early Campanian age (Nannofossil Zone CC18 of Sissingh) overlies the laminated shales at both sites. This interval contains benthic foraminiferal faunas reflecting increasing bottom-water oxygenation and reduced organic-matter flux. This glauconitic chalk is strongly condensed and contains most of the Lower and mid-Campanian. Benthic foraminiferal species indicative of well-oxygenated and more oligotrophic environments characterise the overlying mid- to Upper Campanian nannofossil chalk. During deposition of the nannofossil chalk, a permanent deep-water connection between the central and South Atlantic Oceans is proposed, leading to ventilated and ... Dataset North Atlantic PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-54.341960,-54.199080,9.453830,9.300400) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
207-1257A 207-1259B 207-1259C DRILL Drilling/drill rig Joides Resolution Leg207 North Atlantic Ocean Ocean Drilling Program ODP |
spellingShingle |
207-1257A 207-1259B 207-1259C DRILL Drilling/drill rig Joides Resolution Leg207 North Atlantic Ocean Ocean Drilling Program ODP Friedrich, Oliver Erbacher, Jochen Late Cretaceous benthic foraminiferal assemblages from Demerara Rise, western tropical Atlantic |
topic_facet |
207-1257A 207-1259B 207-1259C DRILL Drilling/drill rig Joides Resolution Leg207 North Atlantic Ocean Ocean Drilling Program ODP |
description |
This paper is based on Santonian–Campanian sediments of Ocean Drilling Program Sites 1257 (2951 mbsl) and 1259 (2353 mbsl) from Demerara Rise (Leg 207, western tropical Atlantic, off Surinam). According to its position, Demerara Rise should have been influenced by the early opening of the Equatorial Atlantic Gateway and the establishment of a bottom-water connection between the central and South Atlantic Oceans during the Late Cretaceous. The investigated benthic foraminiferal faunas demonstrate strong fluctuations in bottom-water oxygenation and organic-matter flux to the sea-floor. The Santonian–earliest Campanian interval is characterised by laminated black shales without benthic foraminifera in the lowermost part, followed by an increasing number of benthic foraminifera. These are indicative of anoxic to dysoxic bottom waters, high organic-matter fluxes and a position within the oxygen minimum zone. At the shallower Site 1259, benthic foraminifera occurred earlier (Santonian) than at the deeper Site 1257 (Early Campanian). This suggests that the shallower site was characterised by fluctuations in the oxygen minimum zone and that a re-oxygenation of the sea-floor started considerably earlier at shallower water-depths. We speculate that this re-oxygenation was related to the ongoing opening of the Equatorial Atlantic Gateway. A condensed glauconitic chalk interval of Early Campanian age (Nannofossil Zone CC18 of Sissingh) overlies the laminated shales at both sites. This interval contains benthic foraminiferal faunas reflecting increasing bottom-water oxygenation and reduced organic-matter flux. This glauconitic chalk is strongly condensed and contains most of the Lower and mid-Campanian. Benthic foraminiferal species indicative of well-oxygenated and more oligotrophic environments characterise the overlying mid- to Upper Campanian nannofossil chalk. During deposition of the nannofossil chalk, a permanent deep-water connection between the central and South Atlantic Oceans is proposed, leading to ventilated and ... |
format |
Dataset |
author |
Friedrich, Oliver Erbacher, Jochen |
author_facet |
Friedrich, Oliver Erbacher, Jochen |
author_sort |
Friedrich, Oliver |
title |
Late Cretaceous benthic foraminiferal assemblages from Demerara Rise, western tropical Atlantic |
title_short |
Late Cretaceous benthic foraminiferal assemblages from Demerara Rise, western tropical Atlantic |
title_full |
Late Cretaceous benthic foraminiferal assemblages from Demerara Rise, western tropical Atlantic |
title_fullStr |
Late Cretaceous benthic foraminiferal assemblages from Demerara Rise, western tropical Atlantic |
title_full_unstemmed |
Late Cretaceous benthic foraminiferal assemblages from Demerara Rise, western tropical Atlantic |
title_sort |
late cretaceous benthic foraminiferal assemblages from demerara rise, western tropical atlantic |
publisher |
PANGAEA |
publishDate |
2006 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.746960 https://doi.org/10.1594/PANGAEA.746960 |
op_coverage |
MEDIAN LATITUDE: 9.377215 * MEDIAN LONGITUDE: -54.270620 * SOUTH-BOUND LATITUDE: 9.300400 * WEST-BOUND LONGITUDE: -54.341960 * NORTH-BOUND LATITUDE: 9.453830 * EAST-BOUND LONGITUDE: -54.199080 * DATE/TIME START: 2003-01-15T14:30:00 * DATE/TIME END: 2003-02-16T13:15:00 |
long_lat |
ENVELOPE(-54.341960,-54.199080,9.453830,9.300400) |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Supplement to: Friedrich, Oliver; Erbacher, Jochen (2006): Benthic foraminiferal assemblages from Demerara Rise (ODP Leg 207, western tropical Atlantic): possible evidence for a progressive opening of the Equatorial Atlantic Gateway. Cretaceous Research, 27(3), 377-397, https://doi.org/10.1016/j.cretres.2005.07.006 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.746960 https://doi.org/10.1594/PANGAEA.746960 |
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.746960 https://doi.org/10.1016/j.cretres.2005.07.006 |
_version_ |
1766136213165572096 |