Glacigenic and glacimarine sedimentation from shelf to trough settings in the NW Barents Sea

Abstract

A PARASOUND (3.5 kHz) sub-bottom echosounder profile acquired across the Spitsbergenbanken between Kveithola and Storfjorden troughs, NW Barents Sea, documents the lateral variation of sedimentary processes from shelf areas to troughs during the post Last Glacial Maximum (LGM) sea-level rise. In particular, while the Spitsbergenbanken and the southern margin of the Storfjorden trough are characterized by superficial glacial till and eventual post-glacial deposits reworked to a certain extent by iceberg keels, the Kveithola trough documents extensive glacimarine and bottom current sedimentation above the glacial till, only partially affected by ice movement. This evidence suggests that both the Spitsbergenbanken and the southern margin of the Storfjorden trough were mostly sediment bypass areas during the post glacial phase, whereas the Kveithola trough was a comparatively protected area in which relatively weak currents allowed the accumulation of fine-grained deposits. These findings highlight a marked lateral sedimentary variability due to local physiography and hydrodynamics in areas that were covered by thick ice sheets during the LGM, which must be taken into account to produce models that describe post-glacial depositional processes.