Weichselian stratigraphy and palaeoenvironments at Bellsund, western Svalbard

Abstract

A coastal cliff facing the ocean at the west coast of Spitsbergen has been studied, and seven formations of Weichselian and Holocene age have been identified. A reconstruction of the palaeoenvironment and glacial history shows that most of the sediments cover isotope stage 5. From the base of the section, the formation 1 and 2 tills show a regional glaciation that reached the continental shelf shortly after the Eemian. Formation 3 consists of glacimarine to marine sediments dated to 105,000–90,000 BP. Amino acid diagenesis indicates that they were deposited during a c. 10,000‐year period of continuous isostatic depression, which indicates contemporaneous glacial loading in the Barents Sea. Foraminifera and molluscs show influx of Atlantic water masses along the west coast of Svalbard at the same time. Local glaciers advanced during the latter part of this period, probably due to the penetration of moist air masses, and deposited formation 4. A widespread weathering horizon shows that the glacial retreat was succeeded by subaerial conditions during the Middle Weichselian. Formation 5 is a till deposited during the Late Weichselian glacial maximum in this area. The glaciation was dominated by ice streams from a dome over southern Spitsbergen, and the last deglaciation of the outer coast is dated to 13,000 BP. A correlation of the events with other areas on Svalbard is discussed, and at least two periods of glaciation in the Barents Sea during the Weichselian are suggested.

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

“…[2]) from an extended valley glacier, or possibly a tributary to a fjord glacier. This local ice-flow signature is similar to what has been noted for other sites on Svalbard, particularly on the west coast [10,63,[69][70][71][72] and has been assumed to reflect a predominantly low-activity, possibly even frozen-bed ice-sheet cover over these inter-fjord areas [2].…”

“…the transition to the last interglacial (MIS 5e), and interglacial conditions are also supported by a diverse foraminiferal fauna [86,87]. We thus correlate the event with event III (units [8][9][10][11] at Leinstranda [129 ± 10 ka; Alexanderson et al 10,28], and further with the events represented by units A1-A2 at Poolepynten (130-100 ka; Alexanderson et al [14]), by Formation B at Kapp Ekholm (130-120 ka; [6,8,15]) and by units 3-4 at Skilvika [63,88] (Fig. 20).…”

“…Of the features seen at Kongsfjordhallet, palaeosols are the ones that most commonly have been described from other pre-Late Weichselian stratigraphic sites in the area, such as Brøggerhalvøya [9,10,59], northern Prins Karls Forland [70] and Bellsund in SW Spitsbergen [63]. The soils are generally formed in beach deposits, or other coarsegrained sediments, and are represented by horizons with pedogenic silt and carbonate precipitation, typically combined with weathered, frost-shattered clasts [e.g.…”

“…Combined with the presence of carbonate precipitates this suggests that the material in the upper part of unit 7 was exposed at, or close to, a ground surface for some time [cf. 59,63].…”

The kinematics of ancient tidewater ice margins: criteria for recognition from grounding-line moraines

“…The resulting moraine therefore tends to have a sheet-like geometry because the groundingline deposits are easily overridden and truncated by the glacier (Fig. 6a; examples in Landvik et al 1992;Lønne 2005). If formed in somewhat deeper (.50 m) water, the moraine assumes a ridge-like topography and the glacier advance may culminate in a brief stillstand ( Fig.…”