Geological Survey in the Moroccan Sahara: Insights from Reguibat Shield

In a recent 10-day expedition to Reguibat Ridge in the Moroccan Sahara, I led a team to explore significant mineral resources and rare geological features. Conducted last May, this mission provided invaluable insights into the region’s potential and uncovered key mineralizations in one of the Sahara’s most remote areas.

?Our first stop was the historic Aghracha mine, an iron-rich site that was developed by the Spanish in the 1970s. Access to this remote location involves driving 150 km from the city of Ed-Dakhla in the direction of Awsard before reaching the starting point of the dirt road. This path extends for over 50 km, crossing numerous nomadic tracks, which adds to the difficulty of navigation. The mine’s history as a colonial site stands as a testament to the industrial activities in the region, but no redevelopment attempts have been made to date.

The mineralization here is largely magnetite, hematite and ilmenite with high grades of vanadium and titanium reported. Iron veins extend for 50-60 meters before being covered by Quaternary sediments and sand dunes, with an average thickness of 2 meters. Spanish drilling data remains unavailable, though old boreholes are still visible on-site (see photos). Based on a report from ONHYM (Office National des Hydrocarbures et des Mines) conducted in 2011 The resources of Aghracha mine is estimated of about 50M tonnes, though no preliminary metallurgical studies have been done due to the remote location and logistical challenges.

Next, we investigated the Awhifirt carbonatites, one of Morocco’s rare carbonatite occurrences. These rocks are globally important as hosts for Rare Earth Elements (REEs). Two distinct types of carbonatites were observed: white and gray, each with unique geochemical and mineralogical characteristics.

- White carbonatites are medium- to coarse-grained rocks, mainly composed of large calcite grains (up to 95 vol%) with apatite (up to 6 vol%) and phlogopite (2-7 vol%), along with accessory magnetite and dolomite. The calcite often forms euhedral to subhedral grains, creating a mosaic texture, while apatite appears as small pill-like grains or prismatic crystals, occasionally rimmed with carbonate-filled fractures. Phlogopite crystals can be as large as 5 mm, showing occasional signs of oxidation and chloritization.

- Gray carbonatites, in contrast, are fine- to medium-grained, composed mainly of calcite (up to 85 vol%) and dolomite (up to 11 vol%), with significant amounts of non-carbonate minerals like apatite (up to 18 vol%) and opaque minerals such as goethite and hematite. Accessory minerals include pyrochlore, monazite, synchysite, and barite.

ONHYM has conducted geophysical surveys in the region, and those interested in further exploration data are encouraged to contact them. Other carbonatite locations in the Sahara include Twihinet, where Managem is conducting drilling, and Glibet Lafhouda. Additionally, the carbonatites of Tamazirt, located in the High Atlas, represents another important carbonatite site in a different geological setting. These sites are currently considered occurrences or showings of REE mineralization, with no developed deposits yet.

From a broader geological perspective, the local setting remains underexplored, with only regional maps at a 1:50 000 scale available. The lack of deep, modern exploration programs, aside from ONHYM’s work, leaves much potential for future discoveries.

Logistically, this part of the Sahara presents significant challenges for exploration and development, given its remoteness and lack of infrastructure. The nearest port is in Ed-Dakhla, roughly 100 km west as the crow flies.

Despite these challenges, our fieldwork involved detailed mapping, sampling, and analysis, shedding light on the potential of these underexplored sites.

Feel free to check out some photos from our fieldwork in the comments section below!

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References :

Volume 9 (Notes & Mém. n° 564) : Les principales mines du Maroc / Main Mines of Morocco.

RJIMATI E., ZEMMOURI A. (2011) : Carte géologique du Maroc au 1/50 000, feuille Aghracha. Notice explicative. Notes et Mém. Serv. Géol. Maroc, N° 504 bis.

R. Benaouda et al. : Occurrence of high-grade LREE allanite-pegmatites and calcite carbonatite dykes in the Ediacaran complex of Aghracha, Oulad Dlim massif (South Morocco), Journal of African Earth Sciences 196 (2022) 104727.

M. Bouabdellah et al.: Discovery of antiskarn-hosted strategic metal mineralization in the Upper Cretaceous Twihinate carbonatite intrusion (West African Craton Margin, Moroccan Sahara), Ore Geology Reviews 149 (2022) 105105.

C.-E. Malainine et al. : Origin of Cretaceous alkaline annular structures in the peri-cratonic terranes of the Reguibat Rise in Morocco: New constraints from carbonatite–silicate pairs and subsolidus processes, Chemical Geology 632 (2023) 121536.