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Mactesh Katan - Small
A hard outer layer of rock covered softer rocks. Erosion relatively quickly removes the softer minerals, and they are washed away from under the harder rock. The harder rocks eventually collapse under their own weight and a crater-like valley structure is formed. In Negev and Sinai makhteshim, the hard rocks are limestone and dolomites, while the inner softer rocks are chalk or sandstone. [1] In most cases, makhteshim only have one drainage system, although the Makhtesh Ramon has three. The Hebrew term makhtesh ordinarily means "crater", and was used to describe these features before the geological formation processes were understood. In fact, proper craters are formed by the impact of a meteor or volcanic eruption. Adopting the Hebrew words allows English speakers to distinguish the two kinds of features; an alternative English term for makhtesh can be "erosion cirque." [2] [edit] Makhteshim The presence of Makteshim is said to be unique to the Negev desert of Israel and the Sinai Peninsula of Egypt although similar features do exist in Turkmenistan (Yor-oilan-duz depression in Badkhyz Highlands) and Iran. [edit] Negev The Negev desert of Southern Israel is home to five Makhteshim; Makhtesh Ramon, Makhtesh Gadol, Makhtesh Katan, and two further tiny makhteshim on Mount Arif, to the south of Makhtesh Ramon. Makhtesh Ramon is exceptional as it is drained by two rivers (Nahal Ramon and Nahal Ardon). It is the largest Makhtesh at over 40km long, 2-10km wide and over 500m deep. The rocks in this makhtesh contain thousands of ammonite fossils, as well as peats from ancient volcanos. Makhtesh Gadol (The Large Makhtesh) At the time of naming, Makhtesh Ramon was uncharted and so this was thought to be the largest Makhtesh. Makhtesh Katan (The Small Makhtesh) is the smallest major makhtesh at 5km by 7km and was charted in 1942 by Jewish explorers.
Size: 6048px × 4032px
Location: Israel
Photo credit: © yoel harel / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: desert, rock