Paleoclimatic evolution of the Galician Continental Shelf (NW Spain) over the last 3000 years: from a storm regime to present condictions
16 pages, 8 figures, 1 table A multiproxy study of the sedimentary record carried out on gravity core CGPL00-1 retrieved from the outer Galician continental shelf (NW of Spain) has allowed us to establish the main climate fluctuations affecting the region during the Upper Holocene. Grain size, TOC,...
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Language: | English |
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2005
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Online Access: | http://hdl.handle.net/10261/277494 https://doi.org/10.1016/j.jmarsys.2004.07.015 |
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ftcsic:oai:digital.csic.es:10261/277494 2024-02-11T10:08:03+01:00 Paleoclimatic evolution of the Galician Continental Shelf (NW Spain) over the last 3000 years: from a storm regime to present condictions González-Álvarez, R. Bernárdez, Patricia Pena, Leopoldo Francés, Guillermo Prego, R. Diz, Paula Vilas, Federico 2005 http://hdl.handle.net/10261/277494 https://doi.org/10.1016/j.jmarsys.2004.07.015 en eng Elsevier https://doi.org/10.1016/j.jmarsys.2004.07.015 Sí Journal of Marine Systems 54(1-4): 245-260 (2005) 0924-7963 http://hdl.handle.net/10261/277494 doi:10.1016/j.jmarsys.2004.07.015 none Paleoclimatology Holocene Subboreal/Subatlantic transition Planktonic foraminifera Storminess Upwelling Galician continental shelf artículo 2005 ftcsic https://doi.org/10.1016/j.jmarsys.2004.07.015 2024-01-16T11:28:03Z 16 pages, 8 figures, 1 table A multiproxy study of the sedimentary record carried out on gravity core CGPL00-1 retrieved from the outer Galician continental shelf (NW of Spain) has allowed us to establish the main climate fluctuations affecting the region during the Upper Holocene. Grain size, TOC, C/N ratio, biogenic opal and planktonic foraminifera are the main analysed parameters. Lithology and grain size distribution lead to identify two sedimentary sequences: a lower half mainly composed by glauconitic sand and a muddy upper half. A chronology has been established based on three AMS radiocarbon ages, 907 cal. BC, 898 cal. BC and 1399 AD, and the aforementioned sedimentary sequences. The obtained radiocarbon ages are the first dated sediment samples for the Galician continental shelf. Geochemical markers show different trends in both sequences: low and/or fluctuating values in the sandy sequence and high and relatively constant values in the upper muddy sequence. The whole sandy interval is interpreted to be a nearly instantaneous deposit from a distal storm ebb current. The muddy interval was deposited in a stable and low-energy marine environment, similar to that found on the present outer shelf. The shift from a storm-dominated shelf to a low-energy environment took place synchronous with the Subboreal/Subatlantic transition, when an increase in storminess appears related to climatic instability. Transitional planktonic foraminiferal assemblage dominates the whole record, although a change to more abundant cold water species at 1420 AD, may relate to an intense upwelling pulse, probably reinforced by colder atmospheric temperatures during the Little Ice Age (LIA). Despite the presence of an upwelling regime since 1420 AD, lesser amount of opal has accumulated in the outer shelf due to enhanced offshore transport and stronger remineralization This work was funded by REN2000-1102 MAR, PGIDT00MAR30103PR and PGIDT00PXI30105PR Projects Peer reviewed Article in Journal/Newspaper Planktonic foraminifera Digital.CSIC (Spanish National Research Council) Journal of Marine Systems 54 1-4 245 260 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
Paleoclimatology Holocene Subboreal/Subatlantic transition Planktonic foraminifera Storminess Upwelling Galician continental shelf |
spellingShingle |
Paleoclimatology Holocene Subboreal/Subatlantic transition Planktonic foraminifera Storminess Upwelling Galician continental shelf González-Álvarez, R. Bernárdez, Patricia Pena, Leopoldo Francés, Guillermo Prego, R. Diz, Paula Vilas, Federico Paleoclimatic evolution of the Galician Continental Shelf (NW Spain) over the last 3000 years: from a storm regime to present condictions |
topic_facet |
Paleoclimatology Holocene Subboreal/Subatlantic transition Planktonic foraminifera Storminess Upwelling Galician continental shelf |
description |
16 pages, 8 figures, 1 table A multiproxy study of the sedimentary record carried out on gravity core CGPL00-1 retrieved from the outer Galician continental shelf (NW of Spain) has allowed us to establish the main climate fluctuations affecting the region during the Upper Holocene. Grain size, TOC, C/N ratio, biogenic opal and planktonic foraminifera are the main analysed parameters. Lithology and grain size distribution lead to identify two sedimentary sequences: a lower half mainly composed by glauconitic sand and a muddy upper half. A chronology has been established based on three AMS radiocarbon ages, 907 cal. BC, 898 cal. BC and 1399 AD, and the aforementioned sedimentary sequences. The obtained radiocarbon ages are the first dated sediment samples for the Galician continental shelf. Geochemical markers show different trends in both sequences: low and/or fluctuating values in the sandy sequence and high and relatively constant values in the upper muddy sequence. The whole sandy interval is interpreted to be a nearly instantaneous deposit from a distal storm ebb current. The muddy interval was deposited in a stable and low-energy marine environment, similar to that found on the present outer shelf. The shift from a storm-dominated shelf to a low-energy environment took place synchronous with the Subboreal/Subatlantic transition, when an increase in storminess appears related to climatic instability. Transitional planktonic foraminiferal assemblage dominates the whole record, although a change to more abundant cold water species at 1420 AD, may relate to an intense upwelling pulse, probably reinforced by colder atmospheric temperatures during the Little Ice Age (LIA). Despite the presence of an upwelling regime since 1420 AD, lesser amount of opal has accumulated in the outer shelf due to enhanced offshore transport and stronger remineralization This work was funded by REN2000-1102 MAR, PGIDT00MAR30103PR and PGIDT00PXI30105PR Projects Peer reviewed |
format |
Article in Journal/Newspaper |
author |
González-Álvarez, R. Bernárdez, Patricia Pena, Leopoldo Francés, Guillermo Prego, R. Diz, Paula Vilas, Federico |
author_facet |
González-Álvarez, R. Bernárdez, Patricia Pena, Leopoldo Francés, Guillermo Prego, R. Diz, Paula Vilas, Federico |
author_sort |
González-Álvarez, R. |
title |
Paleoclimatic evolution of the Galician Continental Shelf (NW Spain) over the last 3000 years: from a storm regime to present condictions |
title_short |
Paleoclimatic evolution of the Galician Continental Shelf (NW Spain) over the last 3000 years: from a storm regime to present condictions |
title_full |
Paleoclimatic evolution of the Galician Continental Shelf (NW Spain) over the last 3000 years: from a storm regime to present condictions |
title_fullStr |
Paleoclimatic evolution of the Galician Continental Shelf (NW Spain) over the last 3000 years: from a storm regime to present condictions |
title_full_unstemmed |
Paleoclimatic evolution of the Galician Continental Shelf (NW Spain) over the last 3000 years: from a storm regime to present condictions |
title_sort |
paleoclimatic evolution of the galician continental shelf (nw spain) over the last 3000 years: from a storm regime to present condictions |
publisher |
Elsevier |
publishDate |
2005 |
url |
http://hdl.handle.net/10261/277494 https://doi.org/10.1016/j.jmarsys.2004.07.015 |
genre |
Planktonic foraminifera |
genre_facet |
Planktonic foraminifera |
op_relation |
https://doi.org/10.1016/j.jmarsys.2004.07.015 Sí Journal of Marine Systems 54(1-4): 245-260 (2005) 0924-7963 http://hdl.handle.net/10261/277494 doi:10.1016/j.jmarsys.2004.07.015 |
op_rights |
none |
op_doi |
https://doi.org/10.1016/j.jmarsys.2004.07.015 |
container_title |
Journal of Marine Systems |
container_volume |
54 |
container_issue |
1-4 |
container_start_page |
245 |
op_container_end_page |
260 |
_version_ |
1790606991354232832 |