Editing Richat Structure (section)

{{Short description|Circular geological feature in the Sahara desert}}
{{Infobox landform
| water             = 
| name              = Richat Structure
| other_name        = ''Tagense''<ref name="Richard-Molard1952a" />
| type              = [[Dome (geology)|Dome]]
| photo             = Richat Structure ISS030-E-12516.jpg
| photo_width       = 250px
| photo_alt         =
| photo_caption     = Image from the [[International Space Station]], 17 December 2011
| map               = Mauritania#Africa
| map_width         =
| map_caption       =Location within [[Mauritania]]##Location within [[Africa]] 
| map_alt           =
| relief            = yes
| label             =
| label_position    =
| mark              =
| marker_size       =
| location          = [[Adrar Plateau]] of the [[Sahara]]
| grid_ref          =
| coordinates       ={{coord|21.114700|-11.394300|format=dms|region:MR_type:landmark_dim:50000|display=inline,title}} 
| coordinates_ref   =
| range             = 
| part_of           =[[Adrar Region]], Mauritania
| water_bodies      =
| elevation_ft      = <!-- or |elevation_m = -->
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| surface_elevation_ref =
| highest_point     =
| highest_elevation =
| highest_coords    =
| length            = 
| width             = 
| area              = <!-- {{Convert|NN|ha|acres}} -->
| depth             =
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| formed_by         =
| geology           = <!-- or |type = -->
| age               =
| orogeny           =
| topo              =
| operator          = 
| designation       = 
| free_label_1      =
| free_data_1       =
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| website           = <!-- {{URL|example.com}} -->
| embed             =
| native_name       = {{native name|ar|قلب الريشات|parensize=90%}}
}}

{{Use dmy dates|date=January 2023}}

The '''Richat Structure''', or '''''Guelb er Richât''''' ({{langx|ar|قلب الريشات|Qalb ar-Rīšāt}}, {{IPA|mey|galb er.riːʃaːt|lang|LL-Q56231 (mey)-Tidjani Saleh-گلب الريشات.wav}}), is a prominent circular geological feature in the [[Adrar Plateau]] of the [[Sahara]]. It is located near [[Ouadane]] in the [[Adrar Region]] of [[Mauritania]]. In [[Hassaniya Arabic]], ''rīšāt'' means ''feathers'' and it is also known locally in Arabic as ''tagense'', referring to the circular opening of the leather pouch that is used to draw water from local wells.<ref name="Richard-Molard1952a">{{Cite journal |last=Richard-Molard |first=J. |year=1952 |title=The Pseudo-boutonniers of Richat |journal=Gouvernement Général de l'Afrique Occidentale Française Bulletin de la Direction des Mines |volume=15 |issue=2 |pages=391–401}}</ref>

It is an eroded [[Dome (geology)|geological dome]], {{convert|40|km|mi}} in diameter, caused by a subsurface [[igneous intrusion]] deforming the overlying [[sedimentary rock]] layers, causing the rock to be exposed as concentric rings with the oldest layers exposed at the centre of the structure. [[Igneous rock]] is exposed inside and there are [[rhyolite]]s and [[gabbro]]s that have undergone [[hydrothermal alteration]], and a central [[Breccia|megabreccia]]. The structure is also the location of exceptional accumulations of [[Acheulean]] [[Paleolithic]] stone tools. It was selected as one of the 100 geological heritage sites identified by the [[International Union of Geological Sciences]] (IUGS) to be of the highest scientific value.<ref name="IUGS2022a">{{Cite web |title=The First 100 IUGS Geological Heritage Sites |url=https://iugs-geoheritage.org/videos-pdfs/iugs_first_100_book_v2.pdf |access-date=3 November 2022 |website=IUGS International Commission on Geoheritage |publisher=IUGS}}</ref>