The depositional history of the Storfjorden and Kveithola trough-mouth fans (TMFs) in the northwestern Barents Sea has been investigatedwithin two coordinated Spanish and Italian projects in the framework of the International Polar Year (IPY) Activity 367, NICE STREAMS. The investigation has been conducted using a multidisciplinary approach to the study of sediment cores positioned on high-resolution multibeam bathymetry and TOPAS/CHIRP sub-bottom profiles. Core correlation and the age model were based on 27AMS 14C samples, rock magnetic parameters, lithofacies sequences, and the presence of marker beds including two oxidized layers marking the post Last GlacialMaximum (LGM) inception of deglaciation (OX-2) and the Younger Dryas cold climatic event (OX-1). Sediment facies analysis allowed the distinction of a number of depositional processes whose onset appears closely related to ice stream dynamics and oceanographic patterns in response to climate change. The glacigenic diamictonwith lowwater content, high density, and high shear strength, deposited during glacial maxima, indicates ice streams grounded at the shelf edge. Massive release of IRD occurred at the inception of deglaciation in response to increased calving rates with possible outer ice streams lift off and collapse. The presence of a severalmeter- 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 were deposited by contour currents under climatic/environmental conditions favorable 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.Wepropose these interlaminated sediments to represent the high-latitudemarine record ofMeltWater Pulse 1a (MWP-1a). Different bathymetric and oceanographic conditions controlled locally the mode of glacial retreat, resulting in different thickness of plumites on the upper continental slope of the Storfjorden and Kveithola TMFs. It is possible that the southern part of Storfjorden TMF received additional sediments from the deglaciation of the neighboring Kveithola ice stream.
Postglacial sedimentary processes on the Storfjorden and Kveithola trough mouth fans: Significance of extreme glacimarine sedimentation / R. G., Lucchi; A., Camerlenghi; M., Rebesco; E., Colmenero Hidalgo; F. J., Sierro; L., Sagnotti; R., Urgeles; R., Melis; C., Morigii; M. A., Bárcena; G., Giorgetti; Villa, Giuliana; Persico, Davide; J. A., Flores; A. S., Rigual Hernández; M. T., Pedrosa; P., Macri; A., Caburlotto. - In: GLOBAL AND PLANETARY CHANGE. - ISSN 0921-8181. - 111:(2013), pp. 309-326. [10.1016/j.gloplacha.2013.10.008]
Postglacial sedimentary processes on the Storfjorden and Kveithola trough mouth fans: Significance of extreme glacimarine sedimentation
VILLA, Giuliana;PERSICO, Davide;
2013-01-01
Abstract
The depositional history of the Storfjorden and Kveithola trough-mouth fans (TMFs) in the northwestern Barents Sea has been investigatedwithin two coordinated Spanish and Italian projects in the framework of the International Polar Year (IPY) Activity 367, NICE STREAMS. The investigation has been conducted using a multidisciplinary approach to the study of sediment cores positioned on high-resolution multibeam bathymetry and TOPAS/CHIRP sub-bottom profiles. Core correlation and the age model were based on 27AMS 14C samples, rock magnetic parameters, lithofacies sequences, and the presence of marker beds including two oxidized layers marking the post Last GlacialMaximum (LGM) inception of deglaciation (OX-2) and the Younger Dryas cold climatic event (OX-1). Sediment facies analysis allowed the distinction of a number of depositional processes whose onset appears closely related to ice stream dynamics and oceanographic patterns in response to climate change. The glacigenic diamictonwith lowwater content, high density, and high shear strength, deposited during glacial maxima, indicates ice streams grounded at the shelf edge. Massive release of IRD occurred at the inception of deglaciation in response to increased calving rates with possible outer ice streams lift off and collapse. The presence of a severalmeter- 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 were deposited by contour currents under climatic/environmental conditions favorable 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.Wepropose these interlaminated sediments to represent the high-latitudemarine record ofMeltWater Pulse 1a (MWP-1a). Different bathymetric and oceanographic conditions controlled locally the mode of glacial retreat, resulting in different thickness of plumites on the upper continental slope of the Storfjorden and Kveithola TMFs. It is possible that the southern part of Storfjorden TMF received additional sediments from the deglaciation of the neighboring Kveithola ice stream.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
