Mapping sediment–landform assemblages to constrain lacustrine sedimentation in a glacier-fed lake catchment in northwest Spitsbergen

Abstract

Changes in the deposition of fine-grained rock-flour in glacier-fed lakes reflect glacier variability. This meltwater-driven signal is, however, often overprinted by other processes. To constrain the signature of lacustrine sedimentation, we mapped the catchment of glacier-fed Lake Hajeren in northwest Spitsbergen, identifying sediment sources and linking them to surface processes. To this end, we employed a combined approach of aerial image interpretation and field mapping. Our map comprises sediment–landform assemblages commonly found in pro-, peri- and paraglacial landsystems on Spitsbergen, including weathered moraines outboard Little Ice Age limits. Based on the presented map, we argue that mass-wasting does not directly impact lake sedimentation. Also, due to the scarcity of fines in historical glacial deposits, we suggest that modified glacigenic sediments only briefly affect a recorded glacier signal, following retreat. These findings highlight the value of geomorphological maps as tools to constrain catchment processes, improving the interpretation of lake sediment records.