I see so many similarities here. Seems that, besides being visually similar features, turns out that the Richat Structure on Earth and Mars' 'crater' in Meridiani share the presence of Hematite (quartz).
13. Richat Structure, Ouadane, Mauritania
This prominent circular feature in the Sahara desert of Mauretania has attracted attention since the earliest space missions because it forms a conspicuous bull's-eye in the otherwise rather featureless expanse of the desert. Described by some as looking like an outsized ammonite in the desert, the structure [which has a diameter of almost 50 kilometers (30 miles)] has become a landmark for shuttle crews. Initially interpreted as a meteorite impact structure because of its high degree of circularity, it is now thought to be merely a symmetrical uplift (circular anticline) that has been laid bare by erosion. Paleozoic quartzites form the resistant beds outlining the structure. The reason for the high degree of circularity is not clear. Some small faults are conspicuous at lower right, in the four o'clock position. (STS-41G, October 1984. Picture #17-33-110.)
From:
http://www.lpi.usra.edu/publications/slidesets/geology.html
Mining activities in Mauritania
More on Mauritania's Hematite and Iron Ore, etc... here and here.
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Mars' Meridiani crater feature:
From Mars Global Surveyor/JPL:
http://mars.jpl.nasa.gov/mgs/msss/camera/images/8_2002_releases/bullseye/index.html
Recently:
[The remarkable terrain at the "center" of the planet (0 degrees latitude and longitude) is called Meridiani Planum. It hosts a rare occurrence of gray crystalline hematite that will be visited by one of the two Mars Exploration Rovers leaving Earth this June. Just to the ENE of the hematite deposit is the eroded, layered terrain seen in this image, which lacks spectral evidence for hematite.]
From Themis:
http://themis.la.asu.edu/zoom-20030417a.html
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It will be interesting to know what (and even what else besides Hematite) Opportunity (MER B) will find in Meridiani.
Marcia
- I hope my html worked and thanks for letting me think out loud. lol
Hematite