The origin of Kaolin in the Béni-Snassène granodiorite sand (Northeastern Morocco) [L'origine du kaolin de l'arène de la granodiorite des Béni-Snassène (Maroc nord-oriental)]

The béni-snassène granitic massif is composed principally of granodiorite that was the object of a strong arenisation accompanied with a locally strong kaolinization. the weathering sequences of this granodiorite have been studied by macroscopic and microscopic analyses,x-ray diffraction (xrd) and chemical analyses (xrf). chemical index of weathering (ciw) and the alteration index of ishikawa (ai) were calculated and used as weathering proxies. the results show that the weathering is mostly meteoric than hydrothermal alteration. the lack of sulphides within the kaolinized zone suggests a supergene kaolinization. however,the influence of the hydrothermal alteration is certain and proven by the presence of pb-zn-cu-ba mineralization indices.