Petrogenesis of metaluminous and peraluminous granitoids from Garga-Sarali zone : evidence of I- and S-type sources (central African fold belt in Cameroon)

  • Authors

    • Daama Isaac University of Ngaoundere
    • Mbowou Gbambie Isaac Bertrand UNIVERSITY OF NGAOUNDERE, Cameroon
    • Nguihdama Dagwaï University of Maroua
    • Ngounouno Ismaïla University of Maroua
  • Petrography; Petrogenesis; Granodiorites; Two-Mica Granites; Garga-Sarali.
  • The Garga-Sarali granitoids outcrop from a metamorphic basement in the central-eastern part of the Central Cameroonian Domain of the Central African fold belt in Cameroon, and are petrographically very complex. They can be divided into two types : (1) Granodiorites of metaluminous type-I, with a fine-grained porphyritic variant texture, consisting of quartrz + orthoclase + microcline + plagioclase + biotite + zircon + oxides ± apatite; (2) and two-mica granites of hyper-aluminous type-S, with a grainy texture, consisting of the same quartzo + k-feldspars + biotite + cordierite ± apatite. These formations both belong to a calc-alkaline-subalkaline, hyper-potassic to shoshonitic signature, and to the tectonic domains of volcanic arc granites. Their emplacement is intimately linked to a crustal parent magma (metagrauwackes and metabsalt-tonalites) that imbibed through the openings in the post-orogenic pan-African lithospheric constraints. Their La/Yb ratio, with (La/Sm)n ranging from 2.18-5.75 ppm, reflects their richness in LREE, and the average Eu/Eu*=0.666 ppm suggests that the residual magma was supersaturated with silica.

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    Isaac , D. ., Gbambie Isaac Bertrand , M. ., Dagwaï , N. ., & Ismaïla , N. . (2024). Petrogenesis of metaluminous and peraluminous granitoids from Garga-Sarali zone : evidence of I- and S-type sources (central African fold belt in Cameroon). International Journal of Advanced Geosciences, 12(1), 47-55.