Fluctuations of the Vestfonna ice margin at Brageneset, Nordaustlandet, Svalbard, after the last glacial maximum

Abstract

Four radiocarbon datings of shells of Mya truncata and Saxicava arctica from the till of the end-moraine of the advance of Vestfonna against Brageneset, Nordaustlandet, between AD 1861 and 1899, gave ages between 8300 BP and 8700 BP. These are from the time when the ice margin had retreated from Brageneset after the last glaciation. An additional age of 7900 BP obtained for Astarteelliptica, also from the end-moraine, shows that the shells in the till represent a mixed death assemblage, as also shown by the composition of the molluscan fauna in general. By comparing the altitudes of the two pumice levels with their altitudes in other areas of Svalbard a curve for the relative uplift of Brageneset could be constructed. According to this curve the highest point of Brageneset at 46.5 m emerged at about 9200 BP, which gives a minimum age for the general deglaciation, an age in agreement with dates obtained from other parts of Nordaustlandet.

Keywords

• glaciation
• deglaciation
• uplifts
• till
• mollusks
• shells
• C-14
• Holocene
• Nordaustlandet
• Svalbard