Earth:Fech fech
Fech fech (Arabic: فش فش) is a very fine powder caused by the erosion of clay-limestone terrain and it is most commonly found in deserts.[1] It consists of a surface horizon of pulverized soil with low particle cohesion[2] protected under a thin crust. Fech fech is derived from ancient lake muds or on certain argillaceous rocks and is one of the desert surfaces that produces dust.[3] It is not determinable from the surface and can therefore pose a significant transportation hazard acting as a surprise "trap" as the ground collapses beneath a vehicle miring it in a quicksand-like substance.
Fech-fech is classified into two types:[2]
- Fech-fech that developed during the Holocene, in lake mud or fluvio-lacustrine sediments.
- Fech-fech that developed from shale.
Fech fech is common in the Qattara Depression in Egypt, making that portion of the Sahara Desert impassable by most vehicles.
See also
References
- ↑ U., Cooke, Ronald (1993). Desert geomorphology. Warren, Andrew., Goudie, Andrew., Cooke, Ronald U.. London: UCL Press. ISBN 0203020596. OCLC 71368681.
- ↑ 2.0 2.1 Encyclopedia of geomorphology. Goudie, Andrew.. London: Routledge. 2004. pp. 364. ISBN 1134482760. OCLC 252833849. https://archive.org/details/encyclopediaofge0001unse.
- ↑ Goudie, Andrew S.; Middleton, Nicholas J., eds. (2006), "Dust Entrainment, Transport and Deposition" (in en), Desert Dust in the Global System, Springer, pp. 13–31, doi:10.1007/3-540-32355-4_2, ISBN 978-3-540-32355-6
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