Weichselian glacial stage in Murchisonfjorden, Nordaustlandet, Svalbard

Abstract

Compared to the other islands in the Svalbard archipelago, Nordaustlandet offers only limited stratigraphical or sedimentological information on its Quaternary deposits. This article aims to fill the gap by presenting new results from glacial geological, sedimentological and chronological studies in the southern Murchisonfjorden area. Field data include reconnaissance mapping and detailed logging of vertical sections along cliff-face outcrops a few metres high adjacent to the present-day shoreline. Combined with OSL and AMS age determinations, these data provide evidence of three successive Weichselian sequences, each represented by the deposition of till followed by the accumulation of shallow marine deposits. Contrary to earlier conclusions, this study demonstrates that the area was occupied by a Late Weichselian glacier (LWG), although the LWG till is thin and discontinuous. Interstadial sublittoral sand related to the Mid-Weichselian interstadial was dated to 38-40 kyr, and an Early Weichselian interstadial to 76-80 kyr. The preservation of older sediments, multiple striae generations and abundant observations of weathered local bedrock material indicate weak glacial erosion within the study area. We suggest that the Late Weichselian glacier was relatively inactive and remained mainly cold-based until the deglaciation. The Isvika sections can be considered a new key site that offers further potential to improve our understanding of the Weichselian stage within the northwestern sector of the Barents-Kara Ice Sheet.

200 ka of glacial events in NW Svalbard: an emergence cycle facies model and regional correlations

“…This age matches well with the early part of the Kapp Ekholm interstadial (Formation F at Kapp Ekholm; Mangerud and Svendsen [8]) as dated by Eccleshall et al ([15]; ca 80 ka), as well as with the Early Weichselian interstadial recognised in Nordaustlandet (80-76 ka, unit 1 at Isvika; Kaakinen et al [16]) (Fig. 20).…”

“…The only other site with raised marine sediments suggested to be of similar age is found at Isvika on Nordaustlandet (unit 6, 40-38 ka: Kaakinen et al [16]) (Fig. 20), although other sites have sediments dated to this time within uncertainties (e.g.…”

“…20). The event may be also be correlated with the slightly older event V (units [15][16][17] at Leinstranda [99 ± 8 ka; 10,28] and with the event represented by unit A3 at Poolepynten (100-85 ka; Alexanderson et al [14]). However, it is possible that these two events-at least the one at Leinstrandarepresent an earlier Early Weichselian interstadial (MIS 5c) than event K-III at Kongsfjordhallet, which falls into MIS 5a.…”

“…luminescence and radiocarbon dating [13]. Despite the lack of tills and incomplete shallowing-upward sequences, correlations of stratigraphic units based on new chronology and better understanding of the depositional environment have recently led to an improved event stratigraphy as well as recognition of previously unknown glacial events [10,[14][15][16].…”

Holocene sedimentary environment of a High−Arctic fjord in Nordaustlandet, Svalbard

“…Solomon et al 2007;Kwok et al 2009;Polyak et al As one of the activities of the International Polar Year 2007Year -2009, an expedition was organised to the Murchisonfjorden area, Nordaustlandet (Pohjola et al 2011). Earlier studies by Kaakinen et al (2009) and Kubischta et al (2010) indicated that coastal sections in Isvika bay contain glacial and marine sediment sequences extend− ing back to the beginning of the Weichselian glacial stage. The marine sediments of the bay could complement the geological history of the area, as was recently shown in the foraminiferal study by Kubischta et al (2011).…”