METALLOGENIC PROVINCES IN MOROCCO

METALLOGENIC PROVINCES IN MOROCCO

Mineral deposits and mining prospects in Morocco are aligned with the metallogenic provinces that are associated with the major geodynamic events that characterize the geology of Morocco.

In this cratonized plinth, the eburnean orogeny is responsible of the gold bearing deposit formation of orogenic golden type whose the most important is the one of LOURIM (Tagragra and Akka buttonhole). Other occurrences are in Kerdou, Zenaga, Ighrem and Tata buttonhole. In this plinth, also exists a pneumatolithic mineralization on beryl, micas and feldspaths taken essentially in pegmatite seams.

MINERALIZATION RELATED TO THE PANAFRICAN CYCLE

Mineralization of Co-Cr Au-Cu related to the pre-panafrican rifting event:

This event gave rise to mineralization in the two paleogeographical domains that it created:

- In the platform, pre-panafrican rifting is responsible for the origin of Bleida’s copper mineralization.
- In the oceanic area, we primarily see the mineralization of the Bou Azzer district of Co-Au (both genetically and spatially related to serpentines), and the gold bearing mineralization of Tafrent in the aggregation at Sirwa, encased by amphibolites in a volcanic rock context.

Precious metal mineralization in the arc context :

In this context, the most typical mineralization are at the Saghro and Ougnat massifs. This includes the Tiouit mineralization of Au-Cu, Imiter silver bearing deposit, Qalaat Mgouna gold bearing mineralization, Taourirt Tamellalt mineralization, and several filonian polymetallic mineralizations like at Boumadine, Tizi Moudou, Assif Imider, and scattering in the lower proterozoic in Ouarzazate.

Copper mineralization related to the Adoudounian basin :

With a typology reminiscent of kupferschiefers, these (post-panafrican) mineralizations are situated at the base of the infracambrian sequence on the Anti-Atlas proterozoic plinth. The paleogeographical constraint of these copper mineralizations is demonstrated by their localization near and around the precambrian paleo reliefs and their position at a regional and stratigraphical level.


MINERALIZATION IN THE HERCYNIAN DOMAIN

The hercynian cycle is also a very productive metallogenic province with mineralization that is distributed among sub-provinces as follows:

Sulfurized pile sub-province of Jebilet guemassa

This is characterized by polymetallic volcanogenic mineralizations tied to the pre-orogenic vulcanism of western Maseta. The largest deposits of this type are: Hajar, Draa Sfar Kettara and Koudiat Aicha.

Peribatholitic mineralization under-province of central Morocco

The term metallogenic province does not apply strictly speaking, because they exist everywhere in the Hercynian Morocco. We recommend to use the notion of metallogenic hercynian age that results in mineralizations around the hercynian granitite. In central Morocco, we have both pneumatolitic and acidic origin mineralizations Achmmach pewter, the pewter deposit of Karit, the fluorine seam of El Hammam, the deposit of F-Pb-Ba-Ag at Zrahina, the pyro metasomatic concentrations of Sn-W around the granite of Ment, and the seams of Pb-Sb or Pb only of which the biggest is the one of Tighza. In the Jbilet, we have the seams of Sidi Bou Othmane, silver of Koudia El Beida and Koudiat Hamra and finally in the high-Atlas, there is the pyrometasomatic deposit of W-Cu-Mo of Azegour and mineralizations of W-Sn-Cu-Au around the Tichka massif.      

         
Recently, a new type of hercynian mineralizations was highlighted, such as the one of Jbel Malek (Au) (Tan-Tan region) and Azouggar N’Tilili (Pb-Zn-Ag-Au) (Southern Draa region)

MINERALIZATIONS IN THE ALPINE REGION

The alpine cycle is characterized by base metals, industrial minerals and rock mineralization. Beyond the filonian mineralizations of the pre-atlasic phase and post-jurassic compression, many mineralizations are stratiform and generated in a sedimentary context tied to the different cycles of maritime sequences. Because of the very large geographic distribution of mineralizations, it is appropriate to classify them by metallogenic age and/or tectonic phase.        

BPGC Filonian mineralization of the pre-atlas phase

This abrupt phase is responsible for many filonian mineralizations at low temperatures either in the Paleozoic plinth or in the triassic-jurassic recovery. We principally note the leaded seams of Tafilalet and Addana, the Pb-Cu-Zn seams of Jebilet and the central High Atlas and the barytine seams in Western and High-Atlas Jebilet.

Stratiform mineralization, basis of sequences

For this kind of mineralization formed in a sedimentary context, the plinth recovery contact played a very important paleo geographic role in the concentration of the metal. In the Triassic, the principal mineralizations are the red-bed lead-containing types of Zayda, the copper occurrences of Argana and gemme salt, gypsum and potash concentration of Mohamedia and Safi. In the Jurassic, there is a stratiform accumulation of manganese in Bouarfa and Tiharatine, the red-bed of Pb-Cu of Sidi-Rhamoune and the gypsum and anhydrite deposit of Safi basin. In the Cretaceous, the most important mineralizations are the manganese concentrations of Imini, the lead, zinc and copper’s mineralization of Merija and Tansrift, the phosphated mineralizations in Khouribga, Gantour, Oulad Abdoun and Bou Kraa basins and the marls and oil shale in Tarfaya, Boujdour, Timahdit and Tangier sectors.  
 
Pb-Zn mineralizations of Mississipi Valley type

For this kind of deposit, the Jurassic constitutes an important metallogenic period. It is the stratoic Kastic or Filonian mineralization, taken by the dolomites. The most important deposits are the ones of Boubker-Touissit Beddiane, Ouled mekta and Mibladen. We also see these kind of mineralizations in the central and oriental high-Atlas and are often localized next to basic intrusions. In the Rif, it is interesting to note the Pb-Zn deposit of Adeldal situated in the limestone dorsal and taken by a Zebred Triassic dolomite.    

Mineralizations tied to basic intrusions  :

These are the nickel occurrences associated to the gabbrous troctolitic intrusions in the central High Atlas (Tassent and Tirrhist).

-Mineralizations tied to neogene volcanism
The principal deposits associated to this volcanism are the bentonite and perlite concentrations in the oriental Rif. The principal deposits of bentonite are the ones of Gourougou, Tidiennit, Amjar, Terbia, Lhammachene, Azzouzet, Ibourhardain, Ikasmeouen and Oued Zmmour. For the perlite, the most important deposit is the one of Tidiennit.

-Placers
The principal placers are localized on the marine littoral. The most important one is Zr-Ti of Bouissafen in Tarfaya region. Occurrences of the same type are localized in Safi, Essaouira, Agadir, and Saîdia regions. On Oulmes granite exists an alluvial placer of cassiterite.