Clay mineralogy of sediment cores from the South-East Atlantic off Namibia
Independent proxies were assessed in two Late Quaternary sediment cores from the eastern South Atlantic to compare deep-water changes during the last 400 kyr. Two cores were recovered from beneath North Atlantic Deep Water (NADW) at approximately 3 000 m depth. Late Quaternary presence of NADW is in...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.730462 2023-05-15T17:13:49+02:00 Clay mineralogy of sediment cores from the South-East Atlantic off Namibia Gingele, Franz Schmiedl, Gerhard MEDIAN LATITUDE: -23.344167 * MEDIAN LONGITUDE: 12.253333 * SOUTH-BOUND LATITUDE: -23.431667 * WEST-BOUND LONGITUDE: 11.698333 * NORTH-BOUND LATITUDE: -23.256667 * EAST-BOUND LONGITUDE: 12.808333 * DATE/TIME START: 1992-01-11T00:00:00 * DATE/TIME END: 1992-01-12T00:00:00 1999-01-14 application/zip, 2 datasets https://doi.pangaea.de/10.1594/PANGAEA.730462 https://doi.org/10.1594/PANGAEA.730462 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.730462 https://doi.org/10.1594/PANGAEA.730462 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Gingele, Franz; Schmiedl, Gerhard (1999): Comparison of independant proxies on deep water advection in the southeast Atlantic off Namibia. South African Journal of Marine Science, 21, 181-190, https://doi.org/10.2989/025776199784126079 GeoB GeoB1710-3 GeoB1712-4 Geosciences University of Bremen Gravity corer (Kiel type) M20/2 Meteor (1986) Namibia continental slope SL Dataset 1999 ftpangaea https://doi.org/10.1594/PANGAEA.730462 https://doi.org/10.2989/025776199784126079 2023-01-20T07:31:37Z Independent proxies were assessed in two Late Quaternary sediment cores from the eastern South Atlantic to compare deep-water changes during the last 400 kyr. Two cores were recovered from beneath North Atlantic Deep Water (NADW) at approximately 3 000 m depth. Late Quaternary presence of NADW is indicated by the Cibicidoides wuellerstorfi assemblage on the Walvis Ridge (Core GeoB 1214) and the Bulimina alazanensis assemblage on the Namibian continental slope (Core GeoB 1710). The propagation of NADW is exclusively observed during interglacials, with maximum factor loadings in Stages 1, 5, 7, 9 and 11. These maxima are consistent with peaks in kaolinite/chlorite ratios and maxima of poorly crystalline smectite in the clay-mineral record. Kaolinite and poorly crystalline smectite are products of intense chemical weathering. They are injected into the NADW at low latitudes, north of the study area, and advected south. Chlorite, which is stable under cold weathering regimes, is a characteristic mineral of water masses of southern origin. During glacial stages, it is advected north with Southern Component Water (SCW). Above the NADW/SCW depths, kaolinite/chlorite ratios vary only slightly without a significant glacial-interglacial pattern, as measured in a core (GeoB 1712) from 1 000 m deep on the same profile of the Namibian continental slope off Walvis Bay. Dataset NADW North Atlantic Deep Water North Atlantic PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(11.698333,12.808333,-23.256667,-23.431667) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
GeoB GeoB1710-3 GeoB1712-4 Geosciences University of Bremen Gravity corer (Kiel type) M20/2 Meteor (1986) Namibia continental slope SL |
spellingShingle |
GeoB GeoB1710-3 GeoB1712-4 Geosciences University of Bremen Gravity corer (Kiel type) M20/2 Meteor (1986) Namibia continental slope SL Gingele, Franz Schmiedl, Gerhard Clay mineralogy of sediment cores from the South-East Atlantic off Namibia |
topic_facet |
GeoB GeoB1710-3 GeoB1712-4 Geosciences University of Bremen Gravity corer (Kiel type) M20/2 Meteor (1986) Namibia continental slope SL |
description |
Independent proxies were assessed in two Late Quaternary sediment cores from the eastern South Atlantic to compare deep-water changes during the last 400 kyr. Two cores were recovered from beneath North Atlantic Deep Water (NADW) at approximately 3 000 m depth. Late Quaternary presence of NADW is indicated by the Cibicidoides wuellerstorfi assemblage on the Walvis Ridge (Core GeoB 1214) and the Bulimina alazanensis assemblage on the Namibian continental slope (Core GeoB 1710). The propagation of NADW is exclusively observed during interglacials, with maximum factor loadings in Stages 1, 5, 7, 9 and 11. These maxima are consistent with peaks in kaolinite/chlorite ratios and maxima of poorly crystalline smectite in the clay-mineral record. Kaolinite and poorly crystalline smectite are products of intense chemical weathering. They are injected into the NADW at low latitudes, north of the study area, and advected south. Chlorite, which is stable under cold weathering regimes, is a characteristic mineral of water masses of southern origin. During glacial stages, it is advected north with Southern Component Water (SCW). Above the NADW/SCW depths, kaolinite/chlorite ratios vary only slightly without a significant glacial-interglacial pattern, as measured in a core (GeoB 1712) from 1 000 m deep on the same profile of the Namibian continental slope off Walvis Bay. |
format |
Dataset |
author |
Gingele, Franz Schmiedl, Gerhard |
author_facet |
Gingele, Franz Schmiedl, Gerhard |
author_sort |
Gingele, Franz |
title |
Clay mineralogy of sediment cores from the South-East Atlantic off Namibia |
title_short |
Clay mineralogy of sediment cores from the South-East Atlantic off Namibia |
title_full |
Clay mineralogy of sediment cores from the South-East Atlantic off Namibia |
title_fullStr |
Clay mineralogy of sediment cores from the South-East Atlantic off Namibia |
title_full_unstemmed |
Clay mineralogy of sediment cores from the South-East Atlantic off Namibia |
title_sort |
clay mineralogy of sediment cores from the south-east atlantic off namibia |
publisher |
PANGAEA |
publishDate |
1999 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.730462 https://doi.org/10.1594/PANGAEA.730462 |
op_coverage |
MEDIAN LATITUDE: -23.344167 * MEDIAN LONGITUDE: 12.253333 * SOUTH-BOUND LATITUDE: -23.431667 * WEST-BOUND LONGITUDE: 11.698333 * NORTH-BOUND LATITUDE: -23.256667 * EAST-BOUND LONGITUDE: 12.808333 * DATE/TIME START: 1992-01-11T00:00:00 * DATE/TIME END: 1992-01-12T00:00:00 |
long_lat |
ENVELOPE(11.698333,12.808333,-23.256667,-23.431667) |
genre |
NADW North Atlantic Deep Water North Atlantic |
genre_facet |
NADW North Atlantic Deep Water North Atlantic |
op_source |
Supplement to: Gingele, Franz; Schmiedl, Gerhard (1999): Comparison of independant proxies on deep water advection in the southeast Atlantic off Namibia. South African Journal of Marine Science, 21, 181-190, https://doi.org/10.2989/025776199784126079 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.730462 https://doi.org/10.1594/PANGAEA.730462 |
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.730462 https://doi.org/10.2989/025776199784126079 |
_version_ |
1766071012248518656 |