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| Format: | Dataset Open Access |
| Language: | en |
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PANGAEA
2006
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| Online Access: | https://doi.org/10.1594/PANGAEA.327024 |
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| _version_ | 1867172262225903616 |
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| author | Romero, Oscar E |
| author_facet | Romero, Oscar E |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Within generally calcareous sediment sequences, layers of variable thickness of the giant diatom Ethmodiscus were found in five cores recovered in the Subtropical South Atlantic between 23° and 33°S from both sides of the Mid-Atlantic Ridge. Two types of oozes occur: (almost) monospecific layers of Ethmodiscus and layers dominated by Ethmodiscus, with several accompanying tropical/subtropical, oligotrophic-water diatoms. The two thickest Ethmodiscus layers occur in GeoB3801-6 around 29°S, and accumulated during late MIS 14 and MIS 12, respectively. Downcore concentrations of Ethmodiscus valves range between 3.4 10 4 and 2.3 10 7 valves g -1. We discuss the ooze formation in the context of migration of frontal systems and changes in the thermohaline circulation. The occurrence of Ethmodiscus oozes in sediments underlying the present-day pelagic, low-nutrient waters is associated with a terminal event of the Mid-Pleistocene Transition at around 530 ka, when the ocean circulation rearranged after a period of reduced NADW production. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_327024 |
| institution | PANGAEA |
| language | en |
| publishDate | 2006 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Valve concentration of Ethmodiscus sp. and carbon in sediment core GeoB3801-6 Romero, Oscar E Calcium carbonate; Calculated, CaCO3=(TC-TOC)*8.333; Carbon, organic, total; Center for Marine Environmental Sciences; Counting, diatoms; DEPTH, sediment/rock; Diatoms, total, per unit sediment mass; Element analyser CHN-O Rapid, Heraeus; GeoB; GeoB3801-6; Geosciences, University of Bremen; Gravity corer (Kiel type); M34/3; MARUM; Meteor (1986); Mid Atlantic Ridge; SL Within generally calcareous sediment sequences, layers of variable thickness of the giant diatom Ethmodiscus were found in five cores recovered in the Subtropical South Atlantic between 23° and 33°S from both sides of the Mid-Atlantic Ridge. Two types of oozes occur: (almost) monospecific layers of Ethmodiscus and layers dominated by Ethmodiscus, with several accompanying tropical/subtropical, oligotrophic-water diatoms. The two thickest Ethmodiscus layers occur in GeoB3801-6 around 29°S, and accumulated during late MIS 14 and MIS 12, respectively. Downcore concentrations of Ethmodiscus valves range between 3.4 10 4 and 2.3 10 7 valves g -1. We discuss the ooze formation in the context of migration of frontal systems and changes in the thermohaline circulation. The occurrence of Ethmodiscus oozes in sediments underlying the present-day pelagic, low-nutrient waters is associated with a terminal event of the Mid-Pleistocene Transition at around 530 ka, when the ocean circulation rearranged after a period of reduced NADW production. |
| title | Valve concentration of Ethmodiscus sp. and carbon in sediment core GeoB3801-6 |
| topic | Calcium carbonate; Calculated, CaCO3=(TC-TOC)*8.333; Carbon, organic, total; Center for Marine Environmental Sciences; Counting, diatoms; DEPTH, sediment/rock; Diatoms, total, per unit sediment mass; Element analyser CHN-O Rapid, Heraeus; GeoB; GeoB3801-6; Geosciences, University of Bremen; Gravity corer (Kiel type); M34/3; MARUM; Meteor (1986); Mid Atlantic Ridge; SL |
| url | https://doi.org/10.1594/PANGAEA.327024 |