Head (geological)
Encyclopedia
Head describes deposits
Deposition (geology)
Deposition is the geological process by which material is added to a landform or land mass. Fluids such as wind and water, as well as sediment flowing via gravity, transport previously eroded sediment, which, at the loss of enough kinetic energy in the fluid, is deposited, building up layers of...

 at the very top of the geological succession
Succession (geology)
A succession, in geology, is a group of rock units or strata that succeed one another in chronological order. Rock successions are often easily seen on exposed sections of a geological column or wall.Based on uncomfortable or comfortable succession....

, that could not be classified more accurately. The term has been used by British geologists since the middle of the 19th century. Areas identified as head include deposits of aeolian origin such as blown sand and loess
Loess
Loess is an aeolian sediment formed by the accumulation of wind-blown silt, typically in the 20–50 micrometre size range, twenty percent or less clay and the balance equal parts sand and silt that are loosely cemented by calcium carbonate...

, slope deposits such as gelifluctates
Gelifluction
Gelifluction, very similar to solifluction, describes the seasonal freeze-thaw action upon waterlogging topsoils which induces downslope movement. Gelifluction is prominent in periglacial regions where snow falls during six to eight months of the year...

 and solifluctates
Solifluction
In geology, solifluction, also known as soil fluction, is a type of mass wasting where waterlogged sediment moves slowly downslope, over impermeable material. It occurs in periglacial environments where melting during the warm season leads to water saturation in the thawed surface material ,...

, and recently eroded soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 material, called colluvium
Colluvium
Colluvium is the name for loose bodies of sediment that have been deposited or built up at the bottom of a low-grade slope or against a barrier on that slope, transported by gravity. The deposits that collect at the foot of a steep slope or cliff are also known by the same name. Colluvium often...

. With geologists becoming more interested in studying the near-surface environment and its related processes, the term head is becoming obsolete.
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