کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4725326 | 1639870 | 2011 | 15 صفحه PDF | دانلود رایگان |
Waxing and waning ice sheets and changing sea levels have been interpreted from the Quaternary stratigraphic record at Leinstranda, Brøggerhalvøya in NW Svalbard. We have identified seven high relative sea-level events, related to glacio-isostatic loading, and separated by at least four glacial events. To establish a chronology for the high sea-level events (interstadials and interglacials) and the intervening glaciations, we have used three different absolute dating methods: optically stimulated luminescence (OSL) of shallow marine deposits, and electron spin resonance (ESR) and radiocarbon (AMS-14C) dating of fossils contained in these sediments. Of the absolute dating methods, OSL has provided the stratigraphically most consistent dataset and which also matches a biostratigraphically inferred interglacial. The ESR ages of mollusc shells suffer from low precision due to unusually large uranium content in most dated shell samples, which in turn is most likely a result of significant recent uranium enrichment of the sediments. Most radiocarbon ages are non-finite. The results show that the high relative sea-level events range in age from the Saalian sensu lato (≥Marine Isotope Stage, MIS, 6) to the early Holocene (MIS 1), and include events OSL-dated to 185 ± 8 ka, 129 ± 10 ka, 99 ± 8 ka and 36 ± 3 ka. The methods used by us and by previous investigators of the same site are compared and assessed, and sources of error, accuracy and precision of ages are discussed.
► High relative sea-level events on NW Svalbard were dated by OSL, ESR and 14C.
► Ages range from the Saalian s.l. (≥MIS 6) to the early Holocene (MIS 1).
► Due to differences between OSL and ESR two alternative chronologies are presented.
► The OSL chronology is preferred based on comparison with other evidence.
► Knowledge of timing of glacial and non-glacial events on Svalbard is improved.
Journal: Quaternary Geochronology - Volume 6, Issues 3–4, June–August 2011, Pages 326–340