Fluvioglacial

Fluvioglacial refers to processes and landforms produced by meltwater streams derived from glaciers. The term is often used interchangeably with glaciofluvial or fluvioglacial, though regional usage varies. It describes the transport of sediments by meltwater, and their deposition beyond the glacier terminus, especially during retreat or deglaciation.

In fluvioglacial settings, braided meltwater channels sort and transport sediment, delivering sands and gravels to form outwash plains and terrace deposits beyond the ice front. Coarser material is deposited closer to the source, while finer sediments accumulate in quieter reaches or lakes, yielding laminated silt and clay and sometimes varves.

Key landforms associated with fluvioglacial processes include outwash plains with extensive sorted gravels, eskers formed from long sinuous subglacial channels, and kames or kettles created by sediment filling openings in stagnant ice or depressions as ice retreats.

Fluvioglacial deposits are typically stratified and well-sorted, in contrast to the unsorted glacial till deposited directly from ice. The relative importance of meltwater discharge, sediment supply, and ice dynamics determines the resulting morphology. The concept applies both to active modern glaciers and to past glacial systems preserved in the Quaternary record, where fluvioglacial sediments help interpret paleoenvironments. Terminology overlaps with glaciofluvial, and some authors reserve fluvioglacial for the hydrological processes specifically linked to meltwater transport.