Marine sedimentary record of Meltwater Pulse 1a along the NW Barents Sea continental margin

Abstract

The upper continental slope of the Storfjorden-Kveithola Trough Mouth Fans (NW Barents Sea) contains a several m-thick late Pleistocene sequence of plumites composed of laminated mud interbedded with sand/silt layers. Radiocarbon ages revealed that deposition occurred during about 130 years at a very high sedimentation rate of 3.4 cm a-1 , at about 7 km from the present shelf break. Palaeomagnetic and rock magnetic analyses confirm the existence of a prominent, short-living sedimentary event. The plumites appear laterally continuous and were correlated with the sedimentary sequences described west of Svalbard and neighboring glacial depositional systems representing a major event at regional scale appointed to correspond to the deep-sea sedimentary record of Meltwater Pulse-1a. We also present new sedimentological and geochemical insights, and multi-beam data adding information on the palaeoenvironmental characteristics during MWP-1a and ice sheet decay in the NW Barents Sea.

Paleomagnetism and rock magnetism from sediments along a continental shelf-to-slope transect in the NW Barents Sea: Implications for geomagnetic and depositional changes during the past 15 thousand years

“…The IRD massive facies was observed in Cores 17603-3 (slope) and 17601-3 (outer trough) overlying the interlaminated sediments and overlaid by the sparsely distributed IRD facies. In agreement with the previous facies interpretation, the massive facies is associated with high iceberg calving rates and/or collapse of the ice stream (Lucchi et al, 2015), whereas the scattered presence of IRD in bioturbated sediments suggests low iceberg calving rates in progressively distal glacimarine conditions (grain size fining up-core, Fig. 2).…”

“…This interval corresponds to plumites deposited at an extremely high sedimentation rate as nearby SVAIS and EGLACOM cores showed. These plumites were previously interpreted to reflect a short time interval of high-accumulation in response to Meltwater Pulse 1a (MWP-1a; Fairbanks, 1989;Hanebuth et al, 2000), which lasted for about two centuries around 14.5 cal ka BP in this area (Lucchi et al, , 2015Sagnotti et al, 2016). This prominent event is recorded in the area with a large lateral variability in deposit thickness and onset ages depending on the depositional setting.…”

“…12). According to Lucchi et al (2013Lucchi et al ( , 2015, the massive IRD layer recovered on the slope record a major ice-sheet instability event occurred at the end (or during) the MWP-1a. Dating on the slope core confirms this hypothesis although it cannot give additional information on the timing of the ice-sheet collapse (during or at the end of the MWP-1a).…”

A High‐Resolution Geomagnetic Relative Paleointensity Record From the Arctic Ocean Deep‐Water Gateway Deposits During the Last 60 kyr

“…Radiocarbon ages on core GS191‐01PC indicate deposition occurred during the Bølling warm interstadial. This interlaminated interval was previously identified in many other cores along this margin (Carbonara et al, ; Caricchi et al, ; Lucchi et al, ; Sagnotti et al, ) and pointed to represent the Arctic marine record of the Meltwater Pulse‐1a (MWP‐1a), dated at about 14.6–14.2 kyr BP (Lucchi et al, , ).…”

Late Quaternary meltwater pulses and sea level change

“…Lucchi et al . () identify the rapid deposition of interlaminated plumites (turbid meltwater deposits) in Storfjorden and Kevithola, Spitsbergen, which they date at 14.65–14.31 cal ka BP and interpret these as a sedimentary signature of MWP1A. Otherwise few observations have been recorded on retreat stages which may have been associated with MWPs.…”