Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic
A high-resolution (10-20 kyr) record of variations in CaCO3 content and dissolution was established for latest Cretaceous (last 0.7 Myr) deep-sea sediments from the South Atlantic Ocean (DSDP Site 516 from the Rio Grande Rise, and sites 525 and 527 from the Walvis Ridge). The degree of fragmentation...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.703254 2023-05-15T18:00:50+02:00 Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic Kucera, Michal Malmgren, Bjorn Sturesson, U MEDIAN LATITUDE: -28.857550 * MEDIAN LONGITUDE: -7.193275 * SOUTH-BOUND LATITUDE: -30.276500 * WEST-BOUND LONGITUDE: -35.285000 * NORTH-BOUND LATITUDE: -28.041500 * EAST-BOUND LONGITUDE: 2.985300 * DATE/TIME START: 1980-03-11T00:00:00 * DATE/TIME END: 1980-06-28T00:00:00 1997-09-09 application/zip, 4 datasets https://doi.pangaea.de/10.1594/PANGAEA.703254 https://doi.org/10.1594/PANGAEA.703254 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.703254 https://doi.org/10.1594/PANGAEA.703254 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Kucera, Michal; Malmgren, Bjorn; Sturesson, U (1997): Foraminiferal dissolution at shallow depths of the Walvis Ridge and Rio Grande Rise during the latest Cretaceous: Inferences for deep-water circulation in the South Atlantic. Palaeogeography, Palaeoclimatology, Palaeoecology, 129(3-4), 195-212, https://doi.org/10.1016/S0031-0182(96)00133-2 72-516F 74-525A 74-527 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 Leg74 South Atlantic South Atlantic/CONT RISE South Atlantic/CREST Dataset 1997 ftpangaea https://doi.org/10.1594/PANGAEA.703254 https://doi.org/10.1016/S0031-0182(96)00133-2 2023-01-20T07:31:13Z A high-resolution (10-20 kyr) record of variations in CaCO3 content and dissolution was established for latest Cretaceous (last 0.7 Myr) deep-sea sediments from the South Atlantic Ocean (DSDP Site 516 from the Rio Grande Rise, and sites 525 and 527 from the Walvis Ridge). The degree of fragmentation of planktonic foraminifera (DFP) was used as a measure of calcite dissolution. High negative correlations between DFP and other independent measures of carbonate dissolution (percentage of sand fraction, absolute abundance of planktonic foraminifera, and planktonic/benthic foraminiferal ratio) validate its use as a sensitive index of calcite dissolution in upper Maastrichtian deep-sea sediments. Very high DFP and a significant negative correlation between DFP and CaCO 3 content suggest that Site 516 was located below the foraminiferal lysocline during the entire interval studied. Such a shallow position of the lysocline (paleodepth of Site 516 was 1.2 km) may be explained by "upwelling" of corrosive deep waters along the southern margin of the Rio Grande Rise. Sites 525 and 527 were located above the foraminiferal lysocline; however, three short periods of enhanced dissolution were recognised at Site 525 (paleodepth 1 km) and one interval of strong dissolution was identified at Site 527 (paleodepth 2.7 km). The lack of correspondence between the dissolution regimes at sites from the Walvis Ridge suggests limited deep-water communication across this physiographic barrier. Two of the dissolution maxima recognised at Site 525 correspond to carbonate maxima at Site 527. Variations in "upwelling" intensity along the Walvis Ridge, resulting in fluctuations in primary productivity in this area, may be the proximal cause of both carbonate cycles at Site 527 and dissolution cycles at Site 525. We suggest that development of the bottom Ekman layer between a hypothetical westward geostrophic current and the topographical height of the Rio Grande Rise-Walvis Ridge system may be a plausible hydrodynamical explanation for the ... Dataset Planktonic foraminifera South Atlantic Ocean PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-35.285000,2.985300,-28.041500,-30.276500) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
72-516F 74-525A 74-527 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 Leg74 South Atlantic South Atlantic/CONT RISE South Atlantic/CREST |
spellingShingle |
72-516F 74-525A 74-527 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 Leg74 South Atlantic South Atlantic/CONT RISE South Atlantic/CREST Kucera, Michal Malmgren, Bjorn Sturesson, U Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic |
topic_facet |
72-516F 74-525A 74-527 Deep Sea Drilling Project DRILL Drilling/drill rig DSDP Glomar Challenger Leg72 Leg74 South Atlantic South Atlantic/CONT RISE South Atlantic/CREST |
description |
A high-resolution (10-20 kyr) record of variations in CaCO3 content and dissolution was established for latest Cretaceous (last 0.7 Myr) deep-sea sediments from the South Atlantic Ocean (DSDP Site 516 from the Rio Grande Rise, and sites 525 and 527 from the Walvis Ridge). The degree of fragmentation of planktonic foraminifera (DFP) was used as a measure of calcite dissolution. High negative correlations between DFP and other independent measures of carbonate dissolution (percentage of sand fraction, absolute abundance of planktonic foraminifera, and planktonic/benthic foraminiferal ratio) validate its use as a sensitive index of calcite dissolution in upper Maastrichtian deep-sea sediments. Very high DFP and a significant negative correlation between DFP and CaCO 3 content suggest that Site 516 was located below the foraminiferal lysocline during the entire interval studied. Such a shallow position of the lysocline (paleodepth of Site 516 was 1.2 km) may be explained by "upwelling" of corrosive deep waters along the southern margin of the Rio Grande Rise. Sites 525 and 527 were located above the foraminiferal lysocline; however, three short periods of enhanced dissolution were recognised at Site 525 (paleodepth 1 km) and one interval of strong dissolution was identified at Site 527 (paleodepth 2.7 km). The lack of correspondence between the dissolution regimes at sites from the Walvis Ridge suggests limited deep-water communication across this physiographic barrier. Two of the dissolution maxima recognised at Site 525 correspond to carbonate maxima at Site 527. Variations in "upwelling" intensity along the Walvis Ridge, resulting in fluctuations in primary productivity in this area, may be the proximal cause of both carbonate cycles at Site 527 and dissolution cycles at Site 525. We suggest that development of the bottom Ekman layer between a hypothetical westward geostrophic current and the topographical height of the Rio Grande Rise-Walvis Ridge system may be a plausible hydrodynamical explanation for the ... |
format |
Dataset |
author |
Kucera, Michal Malmgren, Bjorn Sturesson, U |
author_facet |
Kucera, Michal Malmgren, Bjorn Sturesson, U |
author_sort |
Kucera, Michal |
title |
Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic |
title_short |
Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic |
title_full |
Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic |
title_fullStr |
Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic |
title_full_unstemmed |
Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic |
title_sort |
sedimentology and planktonic foraminiferal dissolution during the latest cretaceous in the south atlantic |
publisher |
PANGAEA |
publishDate |
1997 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.703254 https://doi.org/10.1594/PANGAEA.703254 |
op_coverage |
MEDIAN LATITUDE: -28.857550 * MEDIAN LONGITUDE: -7.193275 * SOUTH-BOUND LATITUDE: -30.276500 * WEST-BOUND LONGITUDE: -35.285000 * NORTH-BOUND LATITUDE: -28.041500 * EAST-BOUND LONGITUDE: 2.985300 * DATE/TIME START: 1980-03-11T00:00:00 * DATE/TIME END: 1980-06-28T00:00:00 |
long_lat |
ENVELOPE(-35.285000,2.985300,-28.041500,-30.276500) |
genre |
Planktonic foraminifera South Atlantic Ocean |
genre_facet |
Planktonic foraminifera South Atlantic Ocean |
op_source |
Supplement to: Kucera, Michal; Malmgren, Bjorn; Sturesson, U (1997): Foraminiferal dissolution at shallow depths of the Walvis Ridge and Rio Grande Rise during the latest Cretaceous: Inferences for deep-water circulation in the South Atlantic. Palaeogeography, Palaeoclimatology, Palaeoecology, 129(3-4), 195-212, https://doi.org/10.1016/S0031-0182(96)00133-2 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.703254 https://doi.org/10.1594/PANGAEA.703254 |
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.703254 https://doi.org/10.1016/S0031-0182(96)00133-2 |
_version_ |
1766170101746237440 |