Module 133 — Geological Intelligence
The Eye of Africa
The Richat Structure is a 40-kilometre geological dome in the Mauritanian Sahara, visible from orbit, formed 100 million years ago when the Atlantic Ocean opened. It is not a meteor crater. It is not Atlantis. It is older than both myths — and more extraordinary than either.
Age of the igneous complex
Diameter of the structure
Mapped within the dome
Source depth of kimberlite magma
Archaeological evidence for Atlantis
Geological Heritage designation, 2022
Satellite Imagery
The Bullseye
Astronauts have used the Richat Structure as an orbital landmark since Gemini IV in 1965. It is easier to see from space than from the ground.
Satellite imagery © Mapbox / © OpenStreetMap. Pan and zoom to explore.
Geological Structure
What Made the Eye
Plan view — hover rings to identify. Scale bar = 10 km.
Central Megabreccia
0–1.5 km from centre · 3 km diameter · Siliceous breccia in limestone-dolomite shelf
~98 Ma (hydrothermal)
Rhyolitic Centres
0–3 km from centre · Two maar remnants · Lava flows + hydrothermally altered tuffs
Cretaceous (undated)
Inner Gabbro Ring Dike
3 km from centre · 20–30 m · Basaltic gabbro (concentric fracture fill)
Cretaceous
Carbonatite Dikes
0–20 km from centre · 1–4 m each × 32 dikes · Massive carbonatite (mantle-sourced, 30 km deep)
85–99 Ma
Outer Gabbro Ring Dike
7–8 km from centre · 50–70 m · Basaltic gabbro (deeper concentric fracture)
Cretaceous
Quartzite Ridges (Cuestas)
3–20 km from centre · Variable · Proterozoic–Ordovician sedimentary (resistant)
541–445 Ma
Kimberlite Intrusions
Northern sector from centre · Sills + 1 plug · Kimberlite (deepest source, >150 km)
~99 Ma
Simplified Cross-Section
Sedimentary layers arched by magmatic uplift (~100 Ma). Erosion exposes concentric rings. Ring dikes (gabbro) mark fracture zones.
The Hypothesis
Was This Atlantis?
In Timaeus and Critias (~360 BCE), Plato described a circular island city with alternating rings of water and land, beyond the Pillars of Hercules, destroyed in a single day. The Richat Structure, with its concentric rings in northwest Africa, has become the most popular candidate among alternative theorists. The mainstream scientific verdict is clear. But the comparison is worth mapping.
Blue = Plato's hypothetical water rings. Brown = Richat's actual quartzite ridges.
| Claim | Plato Says | Richat Shows | Verdict |
|---|---|---|---|
| Concentric rings of water and land | 3 rings of water, 2 of land | 3+ concentric quartzite ridges with valleys between | Superficial match |
| Diameter | ~127 stadia (~23 km) | 40 km | Close if you allow conversion errors |
| Beyond the Pillars of Hercules | West of Gibraltar | Southwest of Gibraltar, inland | Direction matches. Inland does not. |
| Island in the sea | Surrounded by ocean | 500 km from the Atlantic, 400 m above sea level | No evidence of sea level at site |
| Elephants present | Many elephants on the island | Rock art depicts elephants (Green Sahara era) | Match for Green Sahara period |
| Hot and cold springs | Two springs from beneath the earth | Freshwater spring at centre. Hydrothermal history. | Plausible |
| Destroyed in a single day | Sunk beneath the sea in one day | No evidence of catastrophic flooding event at this site | No geological support |
| Archaeological evidence | Advanced civilisation | Stone tools only. No architecture. No pottery. No city. | No evidence of settlement |
The verdict: The Richat Structure is a natural geological formation at least 100 million years old. No archaeological evidence of any settlement — let alone a city — has been found. The concentric ring match is superficial. The structure is 500 km inland at 400 metres elevation. Most classicists consider Atlantis a rhetorical invention, not a geographic description. The IUGS designation as a Geological Heritage Site in 2022 confirms its significance is geological, not mythological.
Timeline
100 Million Years in 17 Moments
Atlantic Ocean opens. Pangaea splits. Magma rises through pre-existing crustal weakness beneath what will become the Sahara. A dome begins to form.
Gabbroic magma fills concentric ring fractures. Kimberlite and carbonatite dikes punch through from 30–150 km depth. Two phreatic eruptions create maar basins at the centre.
Hydrothermal activity creates the central megabreccia — a 3 km collapse zone. The caldera structure is set.
Ninety million years of wind and water. Differential erosion sculpts the dome into concentric rings. Soft rock erodes. Quartzite ridges resist.
The African Humid Period begins. The Sahara is green. The Tamanrasset River flows from the Atlas Mountains past the Richat to the Atlantic. The Eye holds water.
The Green Sahara ends. Desertification accelerates. The Richat dries. Sand advances.
Acheulean stone tools manufactured along the outer ring wadis. Homo erectus or Homo heidelbergensis use the structure as a seasonal hunting ground.
Aterian stone artifacts (Middle Stone Age). Modern humans. Tools found across the structure.
Thousands of stone burial mounds line the protruding land dikes. Rock art depicts horsemen, chariots, bovids, elephants. Libyco-Berber inscriptions at Tin Labbé and Lemqader.
Plato writes Timaeus and Critias. Describes Atlantis: a circular island with alternating rings of water and land, beyond the Pillars of Hercules, rich in elephants and metals.
First described from aerial photographs as "Richât Crater" or "buttonhole" (boutonnière). Richard-Molard suggests laccolithic uplift.
Théodore Monod leads a geological expedition to Mauritania. Records four circular structures including Er Richât. Initially classified as a possible impact crater.
Field and laboratory studies find no shock metamorphism. Coesite report retracted — it was misidentified barite. Impact hypothesis abandoned.
Gemini IV astronauts photograph the structure from orbit. It becomes a landmark for every subsequent space mission.
Matton, Jébrak & Lee publish "Resolving the Richat enigma" in Geology. Confirm: doming + hydrothermal karstification above an alkaline complex.
Matton & Jébrak publish comprehensive paper: "The eye of Africa — an isolated Cretaceous alkaline-hydrothermal complex." The science is settled.
IUGS designates the Richat Structure as one of the first 100 Geological Heritage Sites worldwide.
The Thesis
What the Eye Actually Tells Us
The Richat Structure formed when Africa and South America were still separating. Magma from 150 kilometres below the surface pushed through weaknesses in the crust left over from even older tectonic events. Gabbro filled ring fractures. Carbonatites arrived from 30 kilometres deep. Kimberlite — the rock that carries diamonds — erupted from 150 kilometres down. Then the dome sat in the sun and wind for 100 million years, and erosion did the rest.
The Acheulean tools along the outer wadis are hundreds of thousands of years old. During the Green Sahara, the Eye held water, grew vegetation, attracted elephants. Horsemen left petroglyphs. Libyco-Berber speakers carved inscriptions. Thousands of stone burial mounds line the dikes — and nobody has excavated them yet.
Then Plato wrote about a circular city with rings of water, beyond the Pillars of Hercules, and humans did what humans always do with extraordinary things they cannot fully explain: they told a story about it.
The structure is 100 million years old. The myth is 2,400 years old. The geology does not need the myth. But the myth cannot stop reaching for the geology.
That tension — between what the earth actually is and what we need it to be — is the real story of the Eye of Africa. The Richat Structure is not Atlantis. It is something far older, far stranger, and far more real. A 40-kilometre window into the moment when a continent was born.
Additional satellite imagery (public domain): NASA Earth Observatory hosts multiple Richat Structure images including ISS astronaut photograph ISS030-E-12516 (Dec 2011) and ASTER false-colour composite (Oct 2000). Both freely available at earthobservatory.nasa.gov. NASA/GSFC/JPL imagery is not copyrighted.
Sources
Matton, G. & Jébrak, M. (2014). "The 'eye of Africa' (Richat dome, Mauritania): An isolated Cretaceous alkaline–hydrothermal complex." Journal of African Earth Sciences, 97, 109–124.
Matton, G., Jébrak, M. & Lee, J.K.W. (2005). "Resolving the Richat enigma: Doming and hydrothermal karstification above an alkaline complex." Geology, 33(8), 665–668.
Abdeina, E.H. et al. (2021). "Geophysical modelling of the deep structure of the Richat magmatic intrusion." Arabian Journal of Geosciences, 14(22).
Fudali, R.F. (1969). "Coesite from the Richat Dome, Mauritania: A Misidentification." Science, 166(3902), 228–230.
International Union of Geological Sciences (2022). IUGS Geological Heritage Sites — First 100. Richat Structure designation.
NASA Earth Observatory. ISS030-E-12516 (2011), ASTER image (2000), ISS063-E-43607 (2020). Public domain.
NASA Jet Propulsion Laboratory. Landsat/SRTM composite. Shuttle Radar Topography Mission data.
European Space Agency. ALOS satellite image (Nov 2010).
Plato. Timaeus and Critias. (~360 BCE).
Britannica. "Richat Structure." Updated November 2024.
Wikipedia contributors. "Richat Structure." Accessed February 2026.
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Source: Dancing with Lions · dancingwithlions.com/data/the-eye-of-africa