The post Last Glacial Maximum depositional history of the Storfjorden and Kveithola trough-mouth fans in the North-western Barents Sea has been investigated within two coordinated Spanish and Italian projects in the framework of the International Polar Year (IPY) Activity 367, NICE STREAMS Sediment facies analysis allowed the distinction of a number of depositional processes whose onset appears closely related to ice stream’s dynamics, oceanographic patterns, and sea-level changes in response to climate change. Highly consolidated glacigenic diamicton, deposited during glacial maxima on the upper slope, indicating ice streams grounded at the shelf edge. Massive release of IRD was associated to increased calving rates with possible outer ice streams lift off and collapse at the inception of deglaciation. The presence of a several meter-thick sequence of interlaminated sediments deposited by subglacial outbursts of turbid meltwater (plumites) indicates rapid ice streams' melting and retreat. Crudely-layered and heavily-bioturbated sediments deposited in the later stages of deglaciation by contour currents under climatic/environmental conditions favourable to bioproductivity. The extreme sedimentation rate of 3.4 cm a−1 calculated for the plumites from the upper-slope area indicates a massive, nearly instantaneous (less than 150 years), terrigenous input corresponding to an outstanding meltwater event. We indicate these interlaminated sediments to represent the high-latitude marine record of Meltwater Pulse 1a (MWP- 1a).

Extreme depositional events on the NW-Barents Sea continental margin

MORIGI, CATERINA;
2014

Abstract

The post Last Glacial Maximum depositional history of the Storfjorden and Kveithola trough-mouth fans in the North-western Barents Sea has been investigated within two coordinated Spanish and Italian projects in the framework of the International Polar Year (IPY) Activity 367, NICE STREAMS Sediment facies analysis allowed the distinction of a number of depositional processes whose onset appears closely related to ice stream’s dynamics, oceanographic patterns, and sea-level changes in response to climate change. Highly consolidated glacigenic diamicton, deposited during glacial maxima on the upper slope, indicating ice streams grounded at the shelf edge. Massive release of IRD was associated to increased calving rates with possible outer ice streams lift off and collapse at the inception of deglaciation. The presence of a several meter-thick sequence of interlaminated sediments deposited by subglacial outbursts of turbid meltwater (plumites) indicates rapid ice streams' melting and retreat. Crudely-layered and heavily-bioturbated sediments deposited in the later stages of deglaciation by contour currents under climatic/environmental conditions favourable to bioproductivity. The extreme sedimentation rate of 3.4 cm a−1 calculated for the plumites from the upper-slope area indicates a massive, nearly instantaneous (less than 150 years), terrigenous input corresponding to an outstanding meltwater event. We indicate these interlaminated sediments to represent the high-latitude marine record of Meltwater Pulse 1a (MWP- 1a).
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11568/574667
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