Tectonic reactivation and ore-forming fault systems from the west African Craton margin (Saghro, Anti Atlas, Morocco)

Aabi, Ayoub; Hejja, Younes; Nait Bba, Abdellah; Boujamaoui, Mustapha; Baidder, Lahssen; El Azmi, Mohammed; Maacha, Lhou; Hamzaoui, Abderrazak

doi:10.1016/j.jafrearsci.2024.105182

Cited by 5 publications

(2 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is bordered to the south by the Carboniferous basin of Tindouf and to the north by the southern margin of the High Atlas. The Saghro and Ougnat Massifs (inliers), located in the eastern part of the Anti-Atlas, constitute important anticlinal structures composed of a deformed Proterozoic basement partially overlain by Paleozoic formations, thus hosting several important mineral-rich deposits [16,34,[38][39][40][41][42].…”

Section: Geologic Settingmentioning

confidence: 99%

“…[18] discussed the genetic relationships between faults and barite veins, describing that the barite of the Ougnat Massif is vein-type, and that mineralization-bearing structures are hosted within NE-SW to E-W and NW-SE strike-slip-normal fault system. In contrast to well-studied European deposits such as those in the Catalonian Coastal Ranges (Spain), Western Erzgebirge (Germany) and Sardinia (Italy) [36][37][38][39][40][41], where mineralogy, fluid chemistry, and emplacement ages are thoroughly documented, the barite deposits in Morocco are relatively understudied from a metallogenic perspective. The present, study therefore, aims to investigate, for the first time, fluid inclusions in barite from the Ougnat Massif by combining Sr and S isotopes to (1) characterize vein-type barite mineralization, (2) establish the fluid pathway and source responsible for ore formation, (3) and understand the genetic process of the ore.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Metallogeny and Genesis of Fault-Filling Barite-Sulfide Veins (Ougnat, Morocco): Petrography, Fluid Inclusion, and Sr-S Isotopic Constraints

Samaoui,

Aabi,

Boushaba

et al. 2024

Geosciences

Self Cite

View full text Add to dashboard Cite

The Ougnat Massif of the eastern Anti-Atlas (Morocco) hosts barite and sulfide vein-type deposits of vital economic importance. With over 150 mineralized structures reported in the Ougnat Massif, the ore-bearing ones are predominantly composed of barite, quartz, calcite, and minor portions of sulfides. The mineralized veins are driven by NW-SE and NE-SW to E-W oblique-slip opening faults that cross both the Precambrian basement and its Paleozoic cover. The mineralized structures occur as lenses and sigmoidal veins that follow stepped tension fracture sets oblique to the fault planes. These geometries and kinematic indicators of these structures point to a predominantly normal-sinistral opening in a brittle-ductile tectonic setting. The S isotopic compositions of barite from the Ougnat Massif (+10.8 to +19.5‰) fall mostly within the range of δ34S values of Late Triassic to Jurassic seawater, thus suggesting that some of the SO2− in barite comes from seawater sulfate. This range of δ34S values also corresponds approximately to the hydrothermal barite context. The 87Sr/86Sr ratios of barite, which range from 0.710772 to 0.710816, lie between the radiogenic strontium isotopic compositions of deposition by hydrothermal solutions, and also coincide with the non-radiogenic isotopic signature of Triassic to Jurassic seawater. Based on a fluid inclusions study, the ore-forming fluids were a mixture of two or more fluids. A deep hot fluid with an average temperature of 368 °C leached the granodiorites and volcanic-sedimentary complex of the Ouarzazate Group. This fluid provided the hydrothermal system with most of the Ba, radiogenic Sr, and some of the dissolved S. A second, shallow fluid with an average temperature of 242 °C was derived from Late Triassic to Jurassic seawater. The barite mineralization of the Ougnat Massif constitutes a typical example of vein-type mineralization that occurred along the northern margin of the West African Craton and regionally tied to the central Atlantic opening.

show abstract