Late Cenozoic erosion of the high-latitude southwestern Barents Sea shelf revisited

Abstract

The southwestern Barents Sea has experienced profound erosion during the last ~2.7 m.y. that has resulted in the development of a characteristic glacial morphology of the continental shelf and deposition of a severalkilometer-thick sediment fan along the western margin prograding into the deep sea. In the period from ca. 2.7 to 1.5 Ma, proglacial processes, including fl uvial and glaciofl uvial erosion, dominated. For this period, the total average erosion of the shelf was 170-230 m, the average erosion rate was 0.15-0.2 mm/yr, and the average sedimentation rates on the fan were 16-22 cm/k.y. Subglacial erosion affected an area of ~575,000 km 2 during the period from ca. 1.5 to 0.7 Ma. Total average erosion is estimated at 330-420 m for this interval, and the average erosion rate was 0.4-0.5 mm/yr. Average sedimentation rates were 50-64 cm/k.y. During the last ~0.7 m.y., glacial erosion mainly has occurred beneath fast-fl owing paleo-ice streams topographically confi ned to troughs (~200,000 km 2 ). The total average erosion is estimated at 440-530 m, average erosion rate is 0.6-0.8 mm/yr, and average sedimentation rate on the continental slope is 18-22 cm/k.y. The amount of erosion was mainly determined by the duration of the glaciations and the location, velocity, and basal properties of the ice streams. In total, glacial erosion of the troughs has been relatively high throughout the last ~2.7 m.y. at ~1000-1100 m. For the banks, erosion is inferred to have increased from ca. 2.7 Ma to a peak between 1.5 and 0.7 Ma. Subsequently, little erosion occurred in these areas, which implies a total of 500-650 m of erosion. Compared with other high-latitude areas, our rates are among the highest so far reported. This comparison also demonstrates that there have been large variations in the rate of sediment delivery to the glaciated continental margins.

Assessment of the Cenozoic Erosion Amount Using Monte Carlo Type-Petroleum Systems Modeling of the Hammerfest Basin, Western Barents Sea

“…In the Barents Sea the uplifted terrain is believed to be further affected by several glaciations leading to the shelf erosion in a range of 0.8-1.0 km (Laberg et al, 2012). Glaciations in the southern Barents Sea are thought to commence about 1.0 Ma (Knies et al, 2009) which does not coincide with the ages of erosion detected by AFTA used in this study (Duddy, 1998).…”

Linking an Early Triassic delta to antecedent topography: Source-to-sink study of the southwestern Barents Sea margin

“…During the Cenozoic, the southern Barents Sea Basin and Fennoscandia were mainly in a state of uplift and erosion (Henriksen et al, 2011b;Laberg et al, 2012;Baig et al, 2016). The total erosion along the southern Barents Sea is estimated at ~1200 m, and approximately half of this is estimated to be due glacial erosion during the last 2.7 m.y.…”

“…The total erosion along the southern Barents Sea is estimated at ~1200 m, and approximately half of this is estimated to be due glacial erosion during the last 2.7 m.y. (Laberg et al, 2012;Baig et al, 2016). The erosion onshore in northern Fennoscandia is uncertain.…”

“…12; Winsborrow et al, 2010). This is an area of maximum erosion by topographically controlled ice streams (Laberg et al, 2012). Block-field-mantled high-altitude plateaus occur particularly in the Varanger Peninsula (Fig.…”

The effect of sediment loading in Fennoscandia and the Barents Sea during the last glacial cycle on glacial isostatic adjustment observations

“…2 for the locations. Local observations come from sonar and seismic profiling (Dowdeswell et al, 1996) and coring (Saettem et al, 1992;Laberg and Vorren, 1996;Taylor et al, 2002;Laberg et al, 2012). Other estimates come from modeling based on bathymetry, elevation, and environmental conditions , but these are highly dependent on the amount of ice that is believed to have existed in the Barents and Kara seas.…”