The Makhteshim Country and the connected Great Rift Valley Segment

A makhtesh is a valley eroded at the crest of an anticlinal ridge; it is surrounded by steep walls and drained by a single narrow riverbed (Figs. 7 and 8)that leads to the Arava River and Kikar Badlands segments of the Great Rift Valley (Fig. 9).
Makhtesh Katan a deep round erosion valley at the crest of an anticline, completely surrounded by steep cliffs a picturesque geological window (Albatross) Makhtesh Gadol another anticlinal summit valley, fully surrounded by steep cliffs (Airophan, Avital) Makhtesh Katan overlooks the Great Rift Valley Segment of the Kikar Badlands (satellite image, LANDSAT-5 data, Kaufmann)
The term makhtesh (mortar in Hebrew, plural makhteshim) is international and geology dictionaries refer to the examples of the Negev. The latter are the most perfect ones worldwide and due to the arid climate their rocks are exposed in a symphony of colors (Fig. 10). The makhteshim are geological windows peering into the Earth’s crust, exhibiting features commonly covered by soil and vegetation. The five makhteshim (Fig. 11) are: M. Katan (5 km wide, 8 km long), M. Gadol (5 x 10 km), M. Ramon (the giant, 38 x 6 km, 450 meters deep), and the Arif Twins Makhteshim (each only a few hundreds of meters long) (Fig. 12).

The colorful geology palette - Makhtesh Ramon in a satellite image (Kaufmann, LANDSAT-5 data) The Makhteshim Country a satellite image (Kaufmann, LANDSAT-5 data) The Arif Twin Makhteshim air photo (Hatzav, Airophan)

The Great Rift Valley is a huge landscape channel, bounded at its sides by fault escarpments (Figs. 13 and 14). The rift valley is filled by thousands-of-meters of alluvial sediments, disclosing this is a subsided strip of the crust, revealing separation of the Negev-Sinai sub-plate from the Jordan-Arabia sub-plate. The Makhteshim are geomorphological structures formed at the rim of the separated western sub-plate. Angular unconformities at the flanks of the makhteshim hosting anticlines reveal the latter were formed during a compression phase that predated the makhteshim excavation. Once the deep rift valley landscape channel was formed (Late Neogene) the makhteshim were carved by erosion.

The makhteshim are a geological paradise and till now over 400 scientific and technical publications have appeared, and this seems to be just the beginning. The Ramon Reserve was declared in 1980 a National Geological Park, and from its beginning research was an integral part, and in 1990 was the Ramon Science Center opened, as a scientific outpost, affiliated to the Desert Research Institute at Sde Boqer, the Ben-Gurion University of the Negev, with close cooperation with the Department of Environmental Sciences and Energy Research of the Weizmann Institute of Science.

In 1994 and 1996 a special Governmental Resolution was issued calling for protection of the five makhteshim and the land in-between, and the term Makhteshim Country was coined. The ancient agriculture changed the ecology within the riverbeds of the Negev highland, but it did not penetrate the makhteshim, which are therefore perfectly preserved desert ecosystems, adding to the value of the Makhteshim. Current challenges include:

A 3-D westward looking simulation of the landscape channel of the Arava River and Mt Sedom segment of the Great Rift Valley and the Makhteshim Country highland (Hatzav and Mazor). A 3-D eastward looking simulation of the Makhteshim Country highland and the connected segment of the Great Rift Valley landscape channel (Hatzav and Mazor).
  1. Declaration of the center of Makhtesh Gadol and Makhtesh Ramon as Nature Reserves (it is hard to believe but they have the status of quarrying terrain!);
  2. Inclusion of the Makhteshim Country in UNESCO’s List of World Nature and Heritage Sites; and:
  3. Input into the various national master plans in order to properly incorporate the Makhteshim Country in the development schemes of the Central Negev.

Source book

Krasnov, B. and Mazor, E. Editors (2001): The Makhteshim Country - a Laboratory of Nature; Pensoft Publ., Sofia, 411 pp.

Selected references:

Makhtesh Ramon - Makhteshim Country and the connected Great Rift Valley Segment