Palaeomagnetic records from two varved clay sequences in the Middle Swedish ice marginal zone
| Autor: | Lars Brunnberg, Per Sandgren, Jan Kristiansson, Svante Björck |
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| Rok vydání: | 2008 |
| Předmět: | |
| Zdroj: | Boreas. 17:215-227 |
| ISSN: | 1502-3885 0300-9483 |
| DOI: | 10.1111/j.1502-3885.1988.tb00551.x |
| Popis: | Two varved clay sequences, at Rystad and Tottnas, situated in the Middle Swedish ice marginal zone were analysed palaeomagnetically. Two parallel profiles were sampled and analysed at each site. The varved clay at Rystad was dated by floating varve chronology. The varves at Tottnas can be linked to Swedish time scale, expressed in calendar years B.P. Due to the distance between the sites they cannot be correlated by means of varve diagrams. Palaemagnetic methods were used as an alternative. Based an AF demanetization of pilot samples, the palaeomanetic to be too low, in the order of15d, compared to the site latitude. At Tottnas the inclination records are very close to the expected inclination with respect to the site latitude. Because of a systematic inclination error in the Rystad profiles the correlation was based on the declination records. Statistical comparisons of these records between the two sites indicate that the sediment successions are partly synchronous. It is concluded that the deglaciation at Tottnas started c. 130 years earlier than at Rystad. This mean that the Swedish ice marginal zone east of Rystad will have a more northeasterly extension than previously thought. |
| Databáze: | OpenAIRE |
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