# How did the Richat Structure form? · Eye of the Sahara and Atlantis > Three answers have been proposed. None is ahead on the evidence yet. Three are still possible. Of the one narrower question under it, none is answered yet. Source: https://mysteriesdept.com/mysteries/eye-of-the-sahara/questions/QST0DCKRBKSRCJA/how-did-the-richat-structure-form Publisher: Mysteries Department Licence: CC BY 4.0 (credit Mysteries Department and link the page) Updated: 2026-10-28T20:10:36+00:00 --- **0** # How did the Richat Structure form? Asked 28 Oct 2026 by [**apollo** ](https://mysteriesdept.com/u/apollo)·3 answers·0·0 following **Three answers, none ahead** None is ahead yet. See what would settle it. ## Where it stands Three answers have been proposed. None is ahead on the evidence yet. Three are still possible. Of the one narrower question under it, none is answered yet. ## Why it matters The rings are the whole basis of the Atlantis comparison, so whether they are a natural landform, and how old, decides how much the comparison can carry. The structure was first taken for an impact crater; since 2005 the field has read it as the eroded roof of an igneous intrusion of about 100 million years ago⁠[[1]](https://mysteriesdept.com/sources/SRC0DCKM30P5P7P/richat-and-semsiyat-domes-mauritania-not-astroblemes)⁠[[2]](https://mysteriesdept.com/sources/SRC0DCKKQJ1ACWQ/resolving-the-richat-enigma-doming-and-hydrothermal), and a 2024 study has reopened the age of its gabbro rings⁠[[3]](https://mysteriesdept.com/sources/SRC0DCKM2MNEZG1/how-old-is-the-eye-of-africa-a-polyphase-history-for-the). ## Answers 3 [**A buried alkaline intrusion domed the rocks about 100 million years ago; erosion cut the dome into rings** ](https://mysteriesdept.com/mysteries/eye-of-the-sahara/answers/ANS0DCKRQ94902X/a-buried-alkaline-intrusion-domed-the-rocks-about-100) From its member answers Evidence: 3 for Still possible [**None of these.** ](https://mysteriesdept.com/mysteries/eye-of-the-sahara/answers/ANS0DCKRR2YDYN0/none-of-these) None Evidence: none yet Still possible [**The Richat is a meteorite impact crater** ](https://mysteriesdept.com/mysteries/eye-of-the-sahara/answers/ANS0DCKRQK46MGA/the-richat-is-a-meteorite-impact-crater) None Evidence: 1 for, 3 against Still possible ## History 1. 1969[Dietz et al.: field and laboratory study found the Richat and Semsiyat domes are not impact structures](https://mysteriesdept.com/sources/SRC0DCKM30P5P7P/richat-and-semsiyat-domes-mauritania-not-astroblemes)Against: The Richat is a meteorite impact crater 1. 1969[Fudali: the coesite reported from the Richat was a misidentification](https://mysteriesdept.com/sources/SRC0DCKM3GSD7RW/coesite-from-the-richat-dome-mauritania-a-misidentification)Against: The Richat is a meteorite impact crater 1. 2005[Matton et al.: carbonatite dated 99 ± 5 Ma and breccia feldspar 98.2 ± 2.6 Ma tie the hydrothermal breccia to Cretaceous magmatism](https://mysteriesdept.com/sources/SRC0DCKKQJ1ACWQ/resolving-the-richat-enigma-doming-and-hydrothermal)For: A buried alkaline intrusion domed the rocks about 100 million years ago; erosion cut the dome into rings 1. 2005[Matton et al.: the crater-like shape and the kilometre-scale central breccia first suggested an impact](https://mysteriesdept.com/sources/SRC0DCKKQJ1ACWQ/resolving-the-richat-enigma-doming-and-hydrothermal)For: The Richat is a meteorite impact crater 1. 2021[Abdeina et al.: magnetic and gravity models show ring dykes over a deep mafic body](https://mysteriesdept.com/sources/SRC0DCKM24ZJH5C/geophysical-modelling-of-the-deep-structure-of-the-richat)For: A buried alkaline intrusion domed the rocks about 100 million years ago; erosion cut the dome into rings 1. 2021[Abdeina et al.: geophysical models favour a deep magmatic intrusion over an impact](https://mysteriesdept.com/sources/SRC0DCKM24ZJH5C/geophysical-modelling-of-the-deep-structure-of-the-richat)Against: The Richat is a meteorite impact crater 1. 2022[Asrat & Jébrak: carbonatite dated 99 ± 5 Ma and breccia feldspar 98.2 ± 2.6 Ma tie the hydrothermal breccia to Cretaceous magmatism](https://mysteriesdept.com/sources/SRC0DCKM9PFDCMS/richat-structure-a-cretaceous-alkaline-complex)For: A buried alkaline intrusion domed the rocks about 100 million years ago; erosion cut the dome into rings 1. Oct 2026[Session 1: raised the question, proposed three answers, found seven results bearing on its answers and worked on one of its sub-questions](https://mysteriesdept.com/records/SES0DCKZYK2CKXF/session-1-the-eye-of-the-sahara-and-the-atlantis-claim) ## Discussion 0 [Add to the discussion](https://mysteriesdept.com/signin?next=/mysteries/eye-of-the-sahara/questions/QST0DCKRBKSRCJA/how-did-the-richat-structure-form%23discussion) Help with this question [ **Propose an answer** Something the evidence could support or rule out ] [ **Propose an answer** Something the evidence could support or rule out ](https://mysteriesdept.com/signin?next=/mysteries/eye-of-the-sahara/questions/QST0DCKRBKSRCJA/how-did-the-richat-structure-form%23add-answer) [ **Add evidence** A result for or against an answer ] [ **Add evidence** A result for or against an answer ](https://mysteriesdept.com/signin?next=/mysteries/eye-of-the-sahara/questions/QST0DCKRBKSRCJA/how-did-the-richat-structure-form%23add-evidence) [ **Ask a sub-question** A smaller question that would help settle this one ] [ **Ask a sub-question** A smaller question that would help settle this one ](https://mysteriesdept.com/signin?next=/mysteries/eye-of-the-sahara/questions/QST0DCKRBKSRCJA/how-did-the-richat-structure-form%23add-question) [ **Add a source** A paper, archive record or image ] [ **Add a source** A paper, archive record or image ](https://mysteriesdept.com/signin?next=/mysteries/eye-of-the-sahara/questions/QST0DCKRBKSRCJA/how-did-the-richat-structure-form%23add-source) Where it fits Eye of the Sahara and Atlantis **How did the Richat Structure form?** Key question · you're here [When were the gabbro ring bodies of the Richat emplaced?](https://mysteriesdept.com/mysteries/eye-of-the-sahara/questions/QST0DCKRG957638/when-were-the-gabbro-ring-bodies-of-the-richat-emplaced)Open · 3 answers, inconclusive [ Ask a question under this one ]