A continuous Eemian-Early Weichselian sequence containing pollen and marine fossils at Fjøsanger, western Norway
| Autor: | Eivind Sønstegaard, Sylvi Haldorsen, Jan Mangerud, Hans Petter Sejrup |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Boreas. 10:137-208 |
| ISSN: | 1502-3885 0300-9483 |
| Popis: | A complete interglacial cycle, named the Fjosangerian and correlated with the Eemian by means of its pollen stratigraphy, is found in marine sediments just above the present day sea level outside Bergen, western Norway. At the base of the section there are two basal tills of assumed Saalian (sensu lato) age in which the mineralogy and geochemistry indicate local provenance. Above occur beds of marine silt, sand and gravel, deposited at water depths of between 10 and 50 m. The terrestrial pollen and the marine foraminifera and molluscs indicate a cold-warm-cold sequence with parallel development of the atmospheric and sea surface temperatures. In both environments the flora/fauna indicate an interglacial climatic optimum at least as warm as that during the Holocene. The high relative sea level during the Eemian (at least 30 m above sea level) requires younger neotectonic uplift. The uppermost marine beds are partly glaciomarine silts, as indicated by their mineralogy, drop stones and fauna, and partly interstadial gravels. The pollen indicates an open vegetation throughout these upper beds, and the correlation of the described interstadial with Early Weichselian interstadials elsewhere is essentially unknown. The section is capped by an Early Weichselian basal till containing redeposited fossils, sediments, and weathering products. Several clastic dikes injected from the glacier sole penetrate the till and the interglacial sediments. Radiocarbon dates on wood and shells gave infinite ages. Amino acid epimerization ratios in molluscs support the inferred Eemian age of the deposit. The Fjosangerian is correlated with the Eemian and deep sea oxygen isotope stage 5e; other possible correlations are also discussed. |
| Databáze: | OpenAIRE |
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