Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic)
The deep-water sedimentary processes and morphological features offshore Madeira Island, located in the Central-NE Atlantic have been scantly studied. The analysis of new multibeam bathymetry, echo-sounder profiles and few multichannel seismic reflection profiles allowed us to identify the main geom...
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Format: | Article in Journal/Newspaper |
Language: | Portuguese |
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Marine Geology
2022
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Online Access: | http://hdl.handle.net/10174/32730 https://doi.org/10.1016/j.margeo.2021.106675 |
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ftunivevora:oai:dspace.uevora.pt:10174/32730 2023-09-05T13:13:37+02:00 Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic) Roque, Cristina Hernándes-Molina, Javier Madureira, Pedro Quartau, Rui Magalhães, Vitor Brito, Pedro Vásquez, Tomás Somoza, Luís 2022 http://hdl.handle.net/10174/32730 https://doi.org/10.1016/j.margeo.2021.106675 por por Marine Geology http://hdl.handle.net/10174/32730 cristina.roque@emepc.mm.gov.pt nd pedro@uevora.pt 247 https://doi.org/10.1016/j.margeo.2021.106675 openAccess Central Atlantic Madeira Island Bottom currents Countourite drift field AABW Turbidity currents article 2022 ftunivevora https://doi.org/10.1016/j.margeo.2021.106675 2023-08-14T17:50:10Z The deep-water sedimentary processes and morphological features offshore Madeira Island, located in the Central-NE Atlantic have been scantly studied. The analysis of new multibeam bathymetry, echo-sounder profiles and few multichannel seismic reflection profiles allowed us to identify the main geomorphologies, geomorphic processes and their interplay. Several types of features were identified below 3800 m water depth, shaped mainly by i) the interplay between northward-flowing Antarctic Bottom Water (AABW) and turbidity currents and ii) interaction of the AABW with oceanic reliefs and the Madeira lower slope. Subordinate and localized geomorphic processes consist of tectono-magmatic, slope instability, turbidity currents and fluid migration. The distribution of the morphological features defines three regional geomorphological sectors. Sector 1 represents a deep- seafloor with its abyssal hills, basement highs and seamounts inherited from Early Cretaceous seafloor spreading. Sector 2 is exclusively shaped by turbidity current flows that formed channels and associated levees. Sector 3 presents a more complex morphology dominated by widespread depositional and erosional features formed by AABW circulation, and localized mixed contourite system developed by the interplay between the AABW circulation and WNW-ESE-flowing turbidite currents. The interaction of the AABW with abyssal hills, seamounts and basement ridges leads to the formation of several types of contourites: patch drifts, double-crest mounded bodies, and elongated, mounded and separated drifts. The patch drifts formed downstream of abyssal hills defining an previously unknown field of relatively small contourites. We suggest they may be a result of localized vortexes that formed when the AABW’s flow impinges these oceanic reliefs producing the erosional scours that bound these features. The bottom currents in the area are known to be too weak (1–2 cm s-1)to produce the patch drifts and scours. Therefore, we suggest that these features could be relics ... Article in Journal/Newspaper Antarc* Antarctic Repositório Científico da Universidade de Évora Antarctic Marine Geology 443 106675 |
institution |
Open Polar |
collection |
Repositório Científico da Universidade de Évora |
op_collection_id |
ftunivevora |
language |
Portuguese |
topic |
Central Atlantic Madeira Island Bottom currents Countourite drift field AABW Turbidity currents |
spellingShingle |
Central Atlantic Madeira Island Bottom currents Countourite drift field AABW Turbidity currents Roque, Cristina Hernándes-Molina, Javier Madureira, Pedro Quartau, Rui Magalhães, Vitor Brito, Pedro Vásquez, Tomás Somoza, Luís Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic) |
topic_facet |
Central Atlantic Madeira Island Bottom currents Countourite drift field AABW Turbidity currents |
description |
The deep-water sedimentary processes and morphological features offshore Madeira Island, located in the Central-NE Atlantic have been scantly studied. The analysis of new multibeam bathymetry, echo-sounder profiles and few multichannel seismic reflection profiles allowed us to identify the main geomorphologies, geomorphic processes and their interplay. Several types of features were identified below 3800 m water depth, shaped mainly by i) the interplay between northward-flowing Antarctic Bottom Water (AABW) and turbidity currents and ii) interaction of the AABW with oceanic reliefs and the Madeira lower slope. Subordinate and localized geomorphic processes consist of tectono-magmatic, slope instability, turbidity currents and fluid migration. The distribution of the morphological features defines three regional geomorphological sectors. Sector 1 represents a deep- seafloor with its abyssal hills, basement highs and seamounts inherited from Early Cretaceous seafloor spreading. Sector 2 is exclusively shaped by turbidity current flows that formed channels and associated levees. Sector 3 presents a more complex morphology dominated by widespread depositional and erosional features formed by AABW circulation, and localized mixed contourite system developed by the interplay between the AABW circulation and WNW-ESE-flowing turbidite currents. The interaction of the AABW with abyssal hills, seamounts and basement ridges leads to the formation of several types of contourites: patch drifts, double-crest mounded bodies, and elongated, mounded and separated drifts. The patch drifts formed downstream of abyssal hills defining an previously unknown field of relatively small contourites. We suggest they may be a result of localized vortexes that formed when the AABW’s flow impinges these oceanic reliefs producing the erosional scours that bound these features. The bottom currents in the area are known to be too weak (1–2 cm s-1)to produce the patch drifts and scours. Therefore, we suggest that these features could be relics ... |
format |
Article in Journal/Newspaper |
author |
Roque, Cristina Hernándes-Molina, Javier Madureira, Pedro Quartau, Rui Magalhães, Vitor Brito, Pedro Vásquez, Tomás Somoza, Luís |
author_facet |
Roque, Cristina Hernándes-Molina, Javier Madureira, Pedro Quartau, Rui Magalhães, Vitor Brito, Pedro Vásquez, Tomás Somoza, Luís |
author_sort |
Roque, Cristina |
title |
Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic) |
title_short |
Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic) |
title_full |
Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic) |
title_fullStr |
Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic) |
title_full_unstemmed |
Interplay of deep-marine sedimentary processes with seafloor morphology offshore Madeira Island (Central NE-Atlantic) |
title_sort |
interplay of deep-marine sedimentary processes with seafloor morphology offshore madeira island (central ne-atlantic) |
publisher |
Marine Geology |
publishDate |
2022 |
url |
http://hdl.handle.net/10174/32730 https://doi.org/10.1016/j.margeo.2021.106675 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
http://hdl.handle.net/10174/32730 cristina.roque@emepc.mm.gov.pt nd pedro@uevora.pt 247 https://doi.org/10.1016/j.margeo.2021.106675 |
op_rights |
openAccess |
op_doi |
https://doi.org/10.1016/j.margeo.2021.106675 |
container_title |
Marine Geology |
container_volume |
443 |
container_start_page |
106675 |
_version_ |
1776204831081365504 |