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Is this Atlantis, hiding in plain sight in the Sahara?

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Author Topic: Is this Atlantis, hiding in plain sight in the Sahara?  (Read 99 times)
20,000 Leagues Under the Sea
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« on: October 27, 2018, 08:50:45 pm »

Interpretation

The Richat structure is regarded by geologists as a highly symmetrical and deeply eroded geologic dome. It was first described in the 1930s to 1940s, as Richât Crater or Richât buttonhole (boutonnière du Richât). Richard-Molard (1948) considered it to be the result of a laccolithic thrust.[8] A geological expedition to Mauretania led by Théodore Monod in 1952 recorded four "crateriform or circular irregularities" (accidents cratériformes ou circulaires) in the area, Er Richât, Aouelloul (south of Chinguetti), Temimichat-Ghallaman and Tenoumer.[9] Origin of Er Richât as an impact structure (as is clearly the case with the other three) was briefly considered, but closer study in the 1950s to 1960s suggested that it was formed by terrestrial processes. After extensive field and laboratory studies in the 1960s, no credible evidence has been found for shock metamorphism or any type of deformation indicative of a hypervelocity extraterrestrial impact.[10] While coesite, an indicator of shock metamorphism, had initially been reported as being present in rock samples collected from the Richat Structure, further analysis of rock samples concluded that barite had been misidentified as coesite.[11]

Work on dating the structure was done in the 1990s.[12] Renewed study of the formation of the structure by Matton et al. (2005) and Matton (2008) confirmed the conclusion that it is not an impact structure. The circular distribution of ridges and valleys is explained as the formation of cuestas by the differential erosion of alternating hard and soft rock layers uplifted as a dome by an underlying alkaline igneous complex of Cretaceous age.[13]

A 2011 multianalytical study on the Richat megabreccias concluded that carbonates within the silica-rich megabreccias were created by low-temperature hydrothermal waters, and that the structure requires special protection and further investigation of its origin.[14]
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