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An erg (also sand sea or dune sea, or sand sheet if it lacks dunes) is a broad, flat area of desert covered with wind-swept sand with little or no vegetative cover. [1] The word is derived from the Arabic word ʿirq ( عرق ), meaning "dune field". [ 2 ]
Salt pan – Flat expanse of ground covered with salt and other minerals (salt flat) Sand boil, also known as sand volcano – Cone formed by the ejection of sand on a surface from a central point; Sandhill – Type of ecological community or xeric wildfire-maintained ecosystem; Sandur – Plain formed from glacier sediment transported by meltwater
A sandplain is an area where the soil is sand deposited from elsewhere by processes such as wind or ocean, rather than direct weathering of bedrock. Sandplains are quite flat. There may be dune systems, and given time and the right conditions these may form eolianite ridges, but other than that there is little to give a sandplain any ...
A large dune complex is called a dune field, [7] while broad, flat regions covered with wind-swept sand or dunes, with little or no vegetation, are called ergs or sand seas. [ 8 ] [ 9 ] [ 10 ] Dunes occur in different shapes and sizes, but most kinds of dunes are longer on the stoss (upflow) side, where the sand is pushed up the dune, and have ...
A global analysis published in 2019 suggested that tidal flat ecosystems are as extensive globally as mangroves, covering at least 127,921 km 2 (49,391 sq mi) of the Earth's surface. [3] They are found in sheltered areas such as bays , bayous , lagoons , and estuaries ; they are also seen in freshwater lakes and salty lakes (or inland seas ...
A graded shoreline is a stage in the cycle of coastal development characterised by a flat and straight coastline. It is formed under the influence of wind and water from the original bays, islands, peninsulas and promontories. Sand and gravel is carried away and dumped at other locations depending on the direction and strength of sea currents.
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
2. A flat, shallow sandbank or reef submerged beneath the ocean surface, often with a sandy bottom suitable as an anchorage for seagoing vessels. plain Any broad, flat expanse of land that generally does not show significant variation in topography or elevation. plane table. Also plain table.