Hillsand

Hillsand is a geological term describing hill-like landforms that are dominated by sandy material. Hillsands form where abundant sand is deposited and subsequently reorganized by wind, with water playing a secondary role. They range from small mounds to broad uplands and are typically composed of quartz-rich sand grains that are poorly to moderately sorted. Surfaces are often bare or sparsely vegetated and may display dune-like forms, wind ripples, or scoured profiles.

Formation and processes: In arid and semi-arid regions, aeolian (wind) processes move and accumulate sand to form dunes that coalesce into hills. In river valleys and coastal plains, unstratified or weakly stratified sands can create gentle hills through aggradation and lesser wind action. Vegetation, crusts, and moisture stabilize hillsands; disturbance increases erosion and dust generation.

Distribution and habitat: Hillsands occur on coastal dune fields, inland deserts, and along river valleys worldwide where sandy substrates are exposed. They support xeric grasses, shrubs, and invertebrates adapted to well-drained soils; some areas host specialized plant communities on stabilized dunes.

Human use and management: They are used for grazing, recreation, and sometimes mineral resources. Management aims to reduce erosion, stabilize surfaces with vegetation, and protect infrastructure from sand encroachment.

Naming and scope: The term hillsand is descriptive and not a formal taxonomic category; regional terms and classifications often reflect dune morphology or local geology.