Contourite drifts on distal margins as indicators of established lithospheric breakup
The Albian–Cenomanian breakup sequence (BS) offshore Northwest Iberia is mapped, described and characterised for the first time in terms of its seismic and depositional facies. The interpreted dataset comprises a large grid of regional (2D) seismic-reflection profiles, complemented by Industry and O...
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:59102 2023-05-15T17:35:12+02:00 Contourite drifts on distal margins as indicators of established lithospheric breakup Soares, Duarte M. Alves, Tiago M. Terrinha, Pedro 2014-09-01 https://orca.cardiff.ac.uk/id/eprint/59102/ https://doi.org/10.1016/j.epsl.2014.06.001 unknown Elsevier Soares, Duarte M. https://orca.cardiff.ac.uk/view/cardiffauthors/A172289W.html, Alves, Tiago M. https://orca.cardiff.ac.uk/view/cardiffauthors/A106896T.html orcid:0000-0002-2765-3760 orcid:0000-0002-2765-3760 and Terrinha, Pedro 2014. Contourite drifts on distal margins as indicators of established lithospheric breakup. Earth and Planetary Science Letters 401 , pp. 116-131. 10.1016/j.epsl.2014.06.001 https://doi.org/10.1016/j.epsl.2014.06.001 doi:10.1016/j.epsl.2014.06.001 GC Oceanography QE Geology Article PeerReviewed 2014 ftunivcardiff https://doi.org/10.1016/j.epsl.2014.06.001 2022-10-27T22:38:34Z The Albian–Cenomanian breakup sequence (BS) offshore Northwest Iberia is mapped, described and characterised for the first time in terms of its seismic and depositional facies. The interpreted dataset comprises a large grid of regional (2D) seismic-reflection profiles, complemented by Industry and ODP/DSDP borehole data. Within the BS are observed distinct seismic facies that reflect the presence of: (a) black shales and fine-grained turbidites, (b) mass-transport deposits (MTDs) and coarse-grained turbidites, and (c) contourite drifts. Borehole data show that these depositional systems developed as mixed carbonate–siliciclastic sediments proximally, and as organic-carbon-rich mudstones (black shales) distally on the Northwest Iberia margin. MTDs and turbidites tend to occur on the continental slope, frequently in association with large-scale olistostromes. Distally, these change into interbedded fine-grained turbidites and black shales showing widespread evidence of deep-water current activity towards the top of the BS. Current activity is expressed by intra-BS erosional surfaces and sediment drifts. The results in this paper are important as they demonstrate that contourite drifts are ubiquitous features in the study area after Aptian–Albian lithospheric breakup. Therefore, we interpret the recognition of contourite drifts in Northwest Iberia as having significant palaeogeographic implications. Contourite drifts materialise the onset of important deep-water circulation marking the establishment of oceanic gateways between two fully separated continental margins. As a corollary, we postulate the generation of deep-water geostrophic currents to have had significant impact on North Atlantic climate and ocean circulation during the Albian–Cenomanian, with the record of such impacts being preserved in the contourite drifts analysed in this work. Article in Journal/Newspaper North Atlantic Cardiff University: ORCA (Online Research @ Cardiff) Earth and Planetary Science Letters 401 116 131 |
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Cardiff University: ORCA (Online Research @ Cardiff) |
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ftunivcardiff |
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topic |
GC Oceanography QE Geology |
spellingShingle |
GC Oceanography QE Geology Soares, Duarte M. Alves, Tiago M. Terrinha, Pedro Contourite drifts on distal margins as indicators of established lithospheric breakup |
topic_facet |
GC Oceanography QE Geology |
description |
The Albian–Cenomanian breakup sequence (BS) offshore Northwest Iberia is mapped, described and characterised for the first time in terms of its seismic and depositional facies. The interpreted dataset comprises a large grid of regional (2D) seismic-reflection profiles, complemented by Industry and ODP/DSDP borehole data. Within the BS are observed distinct seismic facies that reflect the presence of: (a) black shales and fine-grained turbidites, (b) mass-transport deposits (MTDs) and coarse-grained turbidites, and (c) contourite drifts. Borehole data show that these depositional systems developed as mixed carbonate–siliciclastic sediments proximally, and as organic-carbon-rich mudstones (black shales) distally on the Northwest Iberia margin. MTDs and turbidites tend to occur on the continental slope, frequently in association with large-scale olistostromes. Distally, these change into interbedded fine-grained turbidites and black shales showing widespread evidence of deep-water current activity towards the top of the BS. Current activity is expressed by intra-BS erosional surfaces and sediment drifts. The results in this paper are important as they demonstrate that contourite drifts are ubiquitous features in the study area after Aptian–Albian lithospheric breakup. Therefore, we interpret the recognition of contourite drifts in Northwest Iberia as having significant palaeogeographic implications. Contourite drifts materialise the onset of important deep-water circulation marking the establishment of oceanic gateways between two fully separated continental margins. As a corollary, we postulate the generation of deep-water geostrophic currents to have had significant impact on North Atlantic climate and ocean circulation during the Albian–Cenomanian, with the record of such impacts being preserved in the contourite drifts analysed in this work. |
format |
Article in Journal/Newspaper |
author |
Soares, Duarte M. Alves, Tiago M. Terrinha, Pedro |
author_facet |
Soares, Duarte M. Alves, Tiago M. Terrinha, Pedro |
author_sort |
Soares, Duarte M. |
title |
Contourite drifts on distal margins as indicators of established lithospheric breakup |
title_short |
Contourite drifts on distal margins as indicators of established lithospheric breakup |
title_full |
Contourite drifts on distal margins as indicators of established lithospheric breakup |
title_fullStr |
Contourite drifts on distal margins as indicators of established lithospheric breakup |
title_full_unstemmed |
Contourite drifts on distal margins as indicators of established lithospheric breakup |
title_sort |
contourite drifts on distal margins as indicators of established lithospheric breakup |
publisher |
Elsevier |
publishDate |
2014 |
url |
https://orca.cardiff.ac.uk/id/eprint/59102/ https://doi.org/10.1016/j.epsl.2014.06.001 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
Soares, Duarte M. https://orca.cardiff.ac.uk/view/cardiffauthors/A172289W.html, Alves, Tiago M. https://orca.cardiff.ac.uk/view/cardiffauthors/A106896T.html orcid:0000-0002-2765-3760 orcid:0000-0002-2765-3760 and Terrinha, Pedro 2014. Contourite drifts on distal margins as indicators of established lithospheric breakup. Earth and Planetary Science Letters 401 , pp. 116-131. 10.1016/j.epsl.2014.06.001 https://doi.org/10.1016/j.epsl.2014.06.001 doi:10.1016/j.epsl.2014.06.001 |
op_doi |
https://doi.org/10.1016/j.epsl.2014.06.001 |
container_title |
Earth and Planetary Science Letters |
container_volume |
401 |
container_start_page |
116 |
op_container_end_page |
131 |
_version_ |
1766134275052142592 |