Photograph of the Richat Structure, Mauritania in West Africa taken during the Gemini IV mission during orbit no. 12, on June 4, 1965. G.E.T. time was 17:46; GMT time was 09:01. Original magazine number was GEM04-16-34670 taken with a modified Hasselblad camera and a 70mm lens. Film type was Kodak Ektachrome MS (S.O. -217), ASA 64, at a lens setting of 250th of a second at f/11. A black &amp; white Master of this image exists. It's photo number is S65-32938.<br>
"The 22-mile-wide Richat structure in Mauritania is one of the most spectacular geologic features in Africa," according to PAUL. D. LOWMAN, JR of the Goddard Space Flight Center, NASA. "Resembling a gigantic bull's-eye, the Richat is a series of concentric ridges of resistant sedimentary rock. Structurally it is a domal uplift: its innermost rocks are Lower Cambrian limestones, surrounded by progressively younger rocks. The origin of this immense dome is not clearly understood. This synoptic view of the entire Richat structure and the surrounding area may throw new light on its origin."
NASA/Gemini 4
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