A hamada (, ) is a type of

desert A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...

landscape consisting of high, largely barren, hard rocky (

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

) plateaus, where most of the

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

has been removed by

deflation In economics, deflation is a decrease in the general price level of goods and services. Deflation occurs when the inflation rate falls below 0% and becomes negative. While inflation reduces the value of currency over time, deflation increases i ...

. The majority of the

Sahara The Sahara (, ) is a desert spanning across North Africa. With an area of , it is the largest hot desert in the world and the list of deserts by area, third-largest desert overall, smaller only than the deserts of Antarctica and the northern Ar ...

is hamada. Other examples are

Negev The Negev ( ; ) or Naqab (), is a desert and semidesert region of southern Israel. The region's largest city and administrative capital is Beersheba (pop. ), in the north. At its southern end is the Gulf of Aqaba and the resort town, resort city ...

desert in

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

and the in Algeria.

Formation

Hamadas are produced by the wind, which removes the fine products of weathering, an aeolian process known as deflation. The finer-grained products are taken away in suspension. At the same time, the sand is removed through saltation and surface creep, leaving behind a landscape of

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

boulder In geology, a boulder (or rarely bowlder) is a rock fragment with size greater than in diameter. Smaller pieces are called cobbles and pebbles. While a boulder may be small enough to move or roll manually, others are extremely massive. In ...

s and bare rock.

Related landforms

Hamada is related to

desert pavement A desert pavement, also called reg (in western Sahara), serir (in eastern Sahara), gibber (in Australia), or saï (in central Asia) is a desert surface covered with closely packed, interlocking angular or rounded rock fragments of pebble and ...

(known variously as reg, serir, gibber, or saï), which occurs as stony plains or depressions covered with gravels or boulders rather than as highland plateaus. Hamadas exist in contrast to '' ergs'', which are large areas of shifting

sand dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat ...

s.McKnight, Tom L. and Darrel Hess. ''Physical Geography: A Landscape Appreciation'', 8th ed., pp. 495-6. Upper Saddle River, NJ: Pearson Education, Inc. 2005. ()

References

Deserts and xeric shrublands Arabic words and phrases {{Geology-stub

Formation

Related landforms

See also

References