The susceptibility of subglacial carbonates to frost weathering

Abstract

The retreat of glaciers over the last century exposed subglacial carbonate, which formed between the glacier ice body and bedrock due to regelation. As such they have implications for paleoenvironmental studies. They are particularly significant as indicators of past glacial presence – since they can form under glacial conditions – and recent glacial retreat, given their high susceptibility to rapid weathering. However, their susceptibility to frost weathering remains relatively unexplored. This study investigates the susceptibility of subglacial carbonates to frost weathering by exposing them to freeze–thaw cycles in a freezing tank. The study demonstrates that subglacial carbonates are inherently weak and prone to weathering, with around a quarter of the samples experiencing breakage into shreds. While exact rates of weathering in natural settings remain challenging to determine, the laboratory conditions provided a framework for evaluating the fundamental response of subglacial carbonates to temperature stresses.