Planktonic foraminifera of sediment core T89-40 on the Walvis Ridge, South Atlantic ...
Core T89-40, eastern Walvis Ridge between the subtropical gyre and Benguela coastal upwelling system, contains three types of levels of abundant left-coiled Neogloboquadrina pachyderma, a cold, eutrophic species, next to subtropical species. Type A peaks (362, 110 and 53-43 ky BP) are accompanied wi...
| Main Authors: | , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
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PANGAEA
2000
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.714256 https://doi.pangaea.de/10.1594/PANGAEA.714256 |
| Summary: | Core T89-40, eastern Walvis Ridge between the subtropical gyre and Benguela coastal upwelling system, contains three types of levels of abundant left-coiled Neogloboquadrina pachyderma, a cold, eutrophic species, next to subtropical species. Type A peaks (362, 110 and 53-43 ky BP) are accompanied with high percentages of other eutrophic species. They are attributed to intensified upwelling in the Northern Benguela region. Type B peaks (129 and 92 ky BP) are accompanied by moderate (<48%) contributions of other eutrophic species and increased numbers of subtropical species. These suggest intensified upwelling in the Northern Benguela cells and may reflect increased seasonal contrasts between the winter upwelling and the subtropical summer conditions.The highest C-peaks, up to 38%, are associated with strongly reduced percentages of other eutrophic species and with abundant subtropical species (Marine Isotopic Stage 11.3 (401 ky) and 9.3 (326 ky)). The subtropical species preceeded the C-peaks by ca 8 ky. ... : Supplement to: Ufkes, Els; Jansen, J H Fred; Schneider, Ralph R (2000): Anomalous occurrendes of Neogloboquadrina pachyderma (left) in a 420-ky upwelling record from Walvis Ridge (SE Atlantic). Marine Micropaleontology, 40(1-2), 23-42 ... |
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