Petrological and geochemical constraints on the origin of apatite ores from Mesozoic alkaline intrusive complexes, Central High-Atlas, Morocco

Phosphate Rocks: A Review of Sedimentary and Igneous Occurrences in Morocco

“…In addition, several recent geological investigations emphasize the role of melts in the genesis of carbonatite-related ores [61,[73][74][75], which provide constraints on the transportation of phosphates and REE/Nb by hydrothermal fluids and their deposition. The role of metasomatism, including late-stage alteration, is also crucial in the ultimate understanding of these phosphate accumulations [19,47,53,72]. However, some apatite accumulations are also reported in the weathering profiles of carbonatites, and sometimes Three major hypotheses are proposed to account for the origin of carbonatite/alkaline magmas: The first is the immiscibility of carbonated silicate magmas at crustal or mantle pressures [68,69].…”

“…Morocco also has several alkaline and carbonatite complexes that remain underexplored in terms of their potential for igneous phosphate resources. The main alkaline and carbonatite complexes capable of harboring this type of mineral deposit are located in three main zones (Figure 11) [19,21,116,117]: (1) the Cenozoic alkaline-carbonatite massif of Tamazeght (High Atlas); (2) the Jurassic-Cretaceous alkaline complex of Imilchil (High Atlas); and (3) the Paleoproterozoic carbonatite intrusions of Gleibat Lafhouda (Dakhla Province).…”

“…The gabbro is the dominant facies in these intrusions (60-70 vol% of the intrusion); it is often associated with monzonitesyenite association bodies, representing the remaining volume of the intrusion. Several of these magmatic structures host gem-quality apatite vein-type ores [19,124]. Apatite from these High Atlas deposits is known through the activity of mineral collectors who recover and resell apatite crystals for international mineral markets (Figure 12A) [19,124,125].…”

“…Several of these magmatic structures host gem-quality apatite vein-type ores [19,124]. Apatite from these High Atlas deposits is known through the activity of mineral collectors who recover and resell apatite crystals for international mineral markets (Figure 12A) [19,124,125]. The main apatite deposits are spatially associated with differentiated magmatic rocks (especially syenites) [19,124].…”

“…Their study could also answer unresolved questions about, phosphogenesis, among others, and provide new insights on the relationship between phosphorite formation and the major biogeochemical cycles, such as the nitrogen and carbon cycles. In addition to sedimentary phosphates, Morocco hosts several carbonatite and carbonatite-alkaline complexes that could be associated with potential resources of igneous phosphate and critical metals [19][20][21][22][23].…”