Debris in Icebergs and Rates of Glaci-Marine Sedimentation: Observations from Spitsbergen and a Simple Model

Debris distribution and content in Spitsbergen icebergs varies, but basal debris-rich layers (often ~1 m-thick) are the most important sources of iceberg rafted material. Angular iceberg rafted clasts in the glaci-marine record imply the presence of nunataks or valley walls, rather than unbroken ice sheet surfaces, indicating paleo-ice mass configuration. Calculated iceberg melt rates imply that most iceberg rafted debris is released within Spitsbergen fjords. Sedimentation from icebergs is calculated as 1 mm a⁻¹ for inner Mollerfjorden, and 8 mm a⁻¹ for inner Kongsfjorden, an order of magnitude lower than total sediment inputs. Turbid subglacial meltwater is a more important debris source. A simple model is proposed to calculate the flux of basal debris in icebergs and iceberg sedimentation rates.