‘Esker’ is a geomorphic feature developed by

An esker is a geomorphic feature characterized as a long, sinuous, and winding ridge composed of sand and gravel [4]. These landforms are specifically classified as glaciofluvial (or fluvioglacial) deposits because they are formed by meltwater streams flowing within, on, or beneath a glacier [4]. During the summer, meltwater accumulates and flows through subglacial tunnels or channels [5]. These streams carry coarse materials like boulders, gravel, and sand, which settle in the ice-walled valley [4]. Once the surrounding ice melts, the accumulated sediment is left behind as a prominent ridge [4]. Unlike glacial till, which is unassorted, esker deposits are typically sorted and stratified due to the action of running water [1]. Therefore, they are distinct from features formed by simple mechanical weathering, standard river action, or wind-blown aeolian processes.

Sources

1. [3] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Landforms and their Evolution > Eskers > p. 56
2. [4] https://en.wikipedia.org/wiki/Fluvioglacial_landform
3. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Landforms and their Evolution > Depositional Landforms > p. 55
4. [5] https://www.sciencedirect.com/science/article/pii/S0926985118307286