Stratigraphic and morphologic constraints on the weichselian glacial history of northern prins karls forland, western svalbard

Abstract

Uncertainty remains if ice-free marginal areas existed on the west coast of Svalbard during the Late Weichselian. Field mapping and correlation to well dated raised beach sequences on nearby Brøggerhalvøya reveal the existence of two generations of raised beach deposits on northern Prins Karls Forland. Distinct beach ridges rise up to the inferred Late Weichselian marine limit at 18 m a.s.l. Discontinuous pre-Late Weichselian beach deposits rise from the Late Weichselian marine limit up to approximately 60 m a.s.l. Expansion of local glaciers during the Late Weichselian is indicated by the limited distribution of a till that overlies parts of the older beach sequence. Stratigraphic data and chronological control indicate deposition in a shallow marine environment before 50 ka BP. Correlation to stratigraphic sites on western Svalbard suggests deposition at c. 70±10 ka. Glaciotectonic structures disclose expansion of local glaciers into the Forlandsundet basin during stage 4 or late stage 5 high relative sea level. Palaeotemperature estimates derived from amino acid ratios indicate that during the time interval c. 70 to 10 ka the area was exposed to cold subaerial temperatures with low rates of racemization. Pedogenesis and frost-shattered clasts at the contact between c. 70 ka deposits and Holocene deposits further indicate a prolonged period of subaerial polar desert conditions during this time interval. The evidence suggests that the Barents Sea ice sheet did not extend across northern Prins Karls Forland during the Weichselian. It is inferred that during the Late Weichselian, ice was drained throughout the major fjords on the west coast of Svalbard and that relatively large marginal areas experienced polar desert conditions and minor expansions of local glaciers.

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].…”

“…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.…”

“…This high relative sea-level event is dated to 60 ± 4 ka, which places it at the transition between MIS4 and MIS3. No event of this age has been documented at Leinstranda, but event K-IV can be correlated to events represented by units A-C (or only unit C) at McVitiepynten (70 ± 10 ka; Andersson et al [70]), unit C at Poolepynten (70-50 ka; Alexanderson et al [14]) and to deposits in the Linnédalen, both the 87-m terrace (54 ± 19 ka; Mangerud et al [6,89]) and units A-C (57 ± 8 ka; Lønne and Mangerud [90]; Mangerud et al [6]) (Fig. 20) [15], cf.…”

Acoustic evidence for a gas migration and release system in Arctic glaciated continental margins offshore NW-Svalbard

“…Glacigenic sediments primarily built the outer shelf of western Svalbard. Highly compacted till deposits are generally absent within the troughs on the inner shelf but they are abundant on the shelf bank areas (Andersson et al, 2000). A previous highresolution study by Landvik et al (2005) from the area west of Prins Karls Forland shows a glacigenic unit crossing the Forlandet Moraine Complex and a pronounced ridge in the western part, which was interpreted as a terminal moraine.…”

Internal characteristics of ice-marginal sediments deduced from georadar profiling and sediment properties (Brøgger Peninsula, Svalbard)

“…The Late Weichselian glacier retreat and the post-glacial uplift as documented in raised marine terraces in the area have intensively been studied (e.g. Forman et al, 1987;Landvik et al, 1987;Héquette, 1987;Lehman and Forman, 1992;Andersson et al, 2000). Accordingly, the terrace of location 1 is mapped as a marine deposit (Kristiansen and Sollid, 1987) and considered as a glaciomarine moraine created by an ice shelf glacier.…”