Current knowledge about the Formation of Erosion Craters - In Israel and worldwide
Visiting the south of Israel, you will come across a very rare geological phenomena - big valleys created by a unique erosion process.
Inside these great valleys, we find various rock sediments and formations, some date back to very ancient times in earths’ history - As these are (Generally speaking) ancient mountains that had been grinded-down by the forces of nature, to form an enclosed valley.
As these special valleys had been considered a unique local phenomena, it got the common Hebrew name - ‘Makhtesh’. This name differs this type of crater from the “normal” craters, which are scattered all across the globe (Caused by a meteorite impact, or a volcanic eruption - Always in a circular shape).
The basic and common explanation for the creation process of Erosion Craters, as offered by local Geologists, defines a 4-stage process, in which every stage is crucial and mandatory:
Source: DSASC
Layering of 2 different rock formations - Ancient Sandstone (Soft and crispy dry sediments), followed and topped by Limestone (harder rock, formed as sea-bed sediments).
Elevation and fractures in earths crust, caused by tectonic shifting in the nearby Syrian-African Rift, creating weakness spots along the mountain tops.
‘Decapping’ of mountain tops, exposing the fragile and soft sandstone layer.
Tilting and water erosion - Tilting of the continental ‘shelf’ towards the Syrian-African Rift, creates height differences which allow ‘washing out’ of the inner, softer sediments, mostly due to seasonal flashfloods. This eventually leads to the collapse of the layers, rocks get grinded in the riverbeds, and the material is being discarded out of the mountain. This process is still ongoing today.
However, latest research suggests a change in the basic criteria for the definition of Erosion Craters, and questions the fact that they were formed only in Israel and north Sinai (Egypt).
You can read about this fascinating research in the following scientific article, published by the DCASC research center: “current knowledge and new advancements in the study of erosional craters and their geoheritage value”.
Read the manifest at the DSASC website. [new window].
They also offer free access to the full PDF article. [new window]
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