Wind key terms (HD) Flashcards
Thermal fracture
The weathering of rock as a result of its rapid heating and cooling
Exfoliation (onion skin)
A process of mechanical weathering that results in the breakdown, splitting, or peeling of the outer rock layers
Crystal growth
The development of rock crystals due to the evaporation of saline water in its cracks
Hydration
The absorption of water into rocks, causing swelling and change of composition
Hydrolysis
The combination of acidic water with minerals, forming clay/ dissolvable salts, that degrade the rock
Oxidation
Oxygen and water cause iron minerals in rocks to oxidise and appear red/brown
Duricrust/ hardpans
The accumulation of salts on the surface
Gypcrete
Gypsum cemented duricrust that forms at the soil surface
Calcrete
Calcium carbonate duricrust that forms at the soil surface
Desert varnish
Where iron and manganese oxides which are weathered at depth, and then are drawn to the surface in solution, are evaporated, leaving a deep red stain
Block disintegration
The breaking off of large rocks from a surface due to repeated expansion of fractures
Granular disintegration
The breaking of rocks into small grains, due to repeated expansion of fractures
Freeze thaw weathering
The freezing and then thawing of water in cracks, causing expansion of fractures
Congelifraction
The repeated cycle of freeze thaw weathering
Deflation
Where wind moves dry, unconsolidated sand, silt and clay particles from the surface and transports them away
Deflation hollow
A depression caused by the removal of fine sediments
Reg or desert pavement
A ‘pavement’ created by large rocks that aren’t transported easily
Abrasion
Where material carried away by moving winds or water hits exposed rock surfaces, thus wearing them away
Surface creep
Where salting particles return to the surface and hit larger particles that are too heavy to hop
Venifacts
Exposed rocks lying on the desert surface that have been abraded/shaped by the wind blown sediment, with smooth sides and sharp edges
Yardangs
A streamlined parallel ridge of rock aligned in the direction of prevailing winds and are seperated by a wind-scoured groove
Zeugen
A collective name for features such as rock pillars/pedestals/mushrooms or yardangs, all formed as a less resistent rock underlies a more-resistent rock
Barchans
Crescent shaped sand dunes
Seif dunes
Knife-edged sand dunes
