Sabcha
The term Sabcha ( Arabic سبخة, DMG Sabḫa ; also Sabkha , Sebkha , Sebkhat , Sebkhet , in the western Sahara Grara ) denotes a shallow basin that is temporarily filled with water and without surface runoff in a semi-arid area.
classification
Sabchas thus belong to the type of ephemeral , non-permanent lakes .
location
They form localized depressions with moist soils that are used for growing grain and vegetables or as grazing land. In contrast to the salt plains (Playas), Sabchas have a flat hinterland. They occur as inland sabcha ("salt marshes") or as coastal sabcha ("salt marsh"). Some authors limit the term to the coastal sabcha.
construction
Thin layers of clayey , silty to fine sandy sediments (very often of Aeolian origin ) are deposited , which are often alternated with thin layers of salt ( gypsum , anhydrite and rock salt ). In the coastal Sabchas there is also often the formation of carbonate sediments. The coastal sabchas are still in the area of the mean water level of the sea or a little above. The groundwater level is therefore only slightly below the sediment surface. The frequent wind erosion ends at the capillary water zone .
literature
- Hans Füchtbauer: Sediments and sedimentary rocks. 4th completely revised edition. 1141 S., Schweizerbart, Stuttgart 1988, ISBN 978-3-510-65138-2 (= Sediment-Petrology , Part 2).
Web links
Individual evidence
- ↑ The expression comes from the ancient Greek adjective ἐφήμερος ephēmeros , for the day, lasting only for one day, transient. Wilhelm Gemoll : Greek-German school and manual dictionary . G. Freytag Verlag / Hölder-Pichler-Tempsky, Munich / Vienna 1965.