Late Quaternary Development of a deep-water Carbonate Mound in the northeast Atlantic
Numerous carbonate mounds have been discovered along the NW European Continental Margin. Many of them are covered by thickets of the ahermatypic corals. To unravel the processes active on the mound, in a case study on Propeller Mound its carbonate budget has been assessed and the mound development h...
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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Universität Bremen
2003
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Online Access: | https://media.suub.uni-bremen.de/handle/elib/1937 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000006917 |
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ftsubbremen:oai:media.suub.uni-bremen.de:Publications/elib/1937 2023-05-15T17:41:24+02:00 Late Quaternary Development of a deep-water Carbonate Mound in the northeast Atlantic Spätquatäre Entwicklung eines ´Carbonate Mounds´ im nordöstlichen Atlantik Dorschel, Boris Hebbeln, Dierk Peckmann, Jörn 2003-09-25 application/pdf https://media.suub.uni-bremen.de/handle/elib/1937 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000006917 eng eng Universität Bremen FB5 Geowissenschaften https://media.suub.uni-bremen.de/handle/elib/1937 urn:nbn:de:gbv:46-diss000006917 info:eu-repo/semantics/openAccess Bitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY) CC-BY Carbonate Mound northeast Atlantic cold-water coral carbonate budget MOW slumping benthic foraminifera bottom currents 80 ddc:80 Dissertation doctoralThesis 2003 ftsubbremen 2022-11-09T07:09:42Z Numerous carbonate mounds have been discovered along the NW European Continental Margin. Many of them are covered by thickets of the ahermatypic corals. To unravel the processes active on the mound, in a case study on Propeller Mound its carbonate budget has been assessed and the mound development has been modelled. In addition benthic foraminiera assemblages have been analysed. Propeller Mound is a ~150m elevated mound in the Porcupine Seabight ca. 90 nautical miles west off South-Ireland. The carbonate budget shows that on Propeller Mound the sediments contain on average >50 wt.-% CaCO3 for the last 175kyrs. In contrast, the sediments from the reference sites off Propeller Mound contain <37 wt.-% CaCO3 for Holocene and <23 wt.-% CaCO3 for glacial sediments. The approximately 30 wt.-% difference between on- and off-mound locations represents the carbonate input due to aragonite added by the corals but extended hiatuses reduce the net long-term CaCO3 accumulation rates on Propeller Mound to ~5% of the off-mound signal. Stable oxygen isotope data, AMS 14C and U/Th ages show that glacial and interglacial sediments were either not deposited or were later eroded on the mound. Instead, almost exclusively interstadial sequences stabilised by loose coral frameworks have been preserved. These sedimentary patterns may be linked to the changing influence of Mediterranean Outflow Water at the mound location. Distinct similarities between benthic foraminiferal assemblages found on-mound with assemblages found in the Mediterranean Sea also point towards a link between MOW and the mound. This interactions result in a spatially and temporally complex sedimentary record on Propeller Mound, impossible to correlate.In contrast to on mound sediments, those deposited in the areas adjacent to Propeller Mound contain more or less continuous records. The discrepancy between on and off-mound sediments imply that at least for the last ~300kyrs Propeller Mound has been shrinking. Doctoral or Postdoctoral Thesis Northeast Atlantic Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) Atlantik Porcupine Seabight ENVELOPE(-13.000,-13.000,50.500,50.500) |
institution |
Open Polar |
collection |
Media SuUB Bremen (Staats- und Universitätsbibliothek Bremen) |
op_collection_id |
ftsubbremen |
language |
English |
topic |
Carbonate Mound northeast Atlantic cold-water coral carbonate budget MOW slumping benthic foraminifera bottom currents 80 ddc:80 |
spellingShingle |
Carbonate Mound northeast Atlantic cold-water coral carbonate budget MOW slumping benthic foraminifera bottom currents 80 ddc:80 Dorschel, Boris Late Quaternary Development of a deep-water Carbonate Mound in the northeast Atlantic |
topic_facet |
Carbonate Mound northeast Atlantic cold-water coral carbonate budget MOW slumping benthic foraminifera bottom currents 80 ddc:80 |
description |
Numerous carbonate mounds have been discovered along the NW European Continental Margin. Many of them are covered by thickets of the ahermatypic corals. To unravel the processes active on the mound, in a case study on Propeller Mound its carbonate budget has been assessed and the mound development has been modelled. In addition benthic foraminiera assemblages have been analysed. Propeller Mound is a ~150m elevated mound in the Porcupine Seabight ca. 90 nautical miles west off South-Ireland. The carbonate budget shows that on Propeller Mound the sediments contain on average >50 wt.-% CaCO3 for the last 175kyrs. In contrast, the sediments from the reference sites off Propeller Mound contain <37 wt.-% CaCO3 for Holocene and <23 wt.-% CaCO3 for glacial sediments. The approximately 30 wt.-% difference between on- and off-mound locations represents the carbonate input due to aragonite added by the corals but extended hiatuses reduce the net long-term CaCO3 accumulation rates on Propeller Mound to ~5% of the off-mound signal. Stable oxygen isotope data, AMS 14C and U/Th ages show that glacial and interglacial sediments were either not deposited or were later eroded on the mound. Instead, almost exclusively interstadial sequences stabilised by loose coral frameworks have been preserved. These sedimentary patterns may be linked to the changing influence of Mediterranean Outflow Water at the mound location. Distinct similarities between benthic foraminiferal assemblages found on-mound with assemblages found in the Mediterranean Sea also point towards a link between MOW and the mound. This interactions result in a spatially and temporally complex sedimentary record on Propeller Mound, impossible to correlate.In contrast to on mound sediments, those deposited in the areas adjacent to Propeller Mound contain more or less continuous records. The discrepancy between on and off-mound sediments imply that at least for the last ~300kyrs Propeller Mound has been shrinking. |
author2 |
Hebbeln, Dierk Peckmann, Jörn |
format |
Doctoral or Postdoctoral Thesis |
author |
Dorschel, Boris |
author_facet |
Dorschel, Boris |
author_sort |
Dorschel, Boris |
title |
Late Quaternary Development of a deep-water Carbonate Mound in the northeast Atlantic |
title_short |
Late Quaternary Development of a deep-water Carbonate Mound in the northeast Atlantic |
title_full |
Late Quaternary Development of a deep-water Carbonate Mound in the northeast Atlantic |
title_fullStr |
Late Quaternary Development of a deep-water Carbonate Mound in the northeast Atlantic |
title_full_unstemmed |
Late Quaternary Development of a deep-water Carbonate Mound in the northeast Atlantic |
title_sort |
late quaternary development of a deep-water carbonate mound in the northeast atlantic |
publisher |
Universität Bremen |
publishDate |
2003 |
url |
https://media.suub.uni-bremen.de/handle/elib/1937 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000006917 |
long_lat |
ENVELOPE(-13.000,-13.000,50.500,50.500) |
geographic |
Atlantik Porcupine Seabight |
geographic_facet |
Atlantik Porcupine Seabight |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_relation |
https://media.suub.uni-bremen.de/handle/elib/1937 urn:nbn:de:gbv:46-diss000006917 |
op_rights |
info:eu-repo/semantics/openAccess Bitte wählen Sie eine Lizenz aus: (Unsere Empfehlung: CC-BY) |
op_rightsnorm |
CC-BY |
_version_ |
1766142923981717504 |