Mineralogy and Geochemistry of the Guenfouda Clay Deposit, Jerada Province, Northeastern Morocco

Abstract

peer reviewedThe Guenfouda clay deposit is located at about 36km to the southwest of Oujda city and 6km to the south of Guenfouda village. It belongs to the Jerada Province of the northeastern Morocco and hosted within the Upper Visean calc-alkaline dacite lava interbedded within a schisto-volcanic complex. This deposit is mined for more than 15 years and the product being mainly used for refractories and industrial ceramics. This clay deposit is funnel or trough-like in form, narrowing downwards and display a E–W trend, which follows the major dextral strike-slip fault that passes through the south of the deposit. Based on mineral assemblages, four lateral alteration zones were defined from the north to south parts of the deposit: the Illite zone, the Pyrophyllite-illite zone, the Pyrophyllite zone and the Quartz zone. The presence of high-temperature minerals such as pyrophyllite, diaspore, the alteration zonation pattern and the chemical characteristics are diagnostic of hypogene origin. However, the variation diagrams, Zr vs TiO2 and P2O5 vs SO3 as well as the values of the chemical Index of Weathering (CIW) and the Alteration Index (AI) revealed a mixed type. It seems that the genesis of Guenfouda clay deposit was first controlled by the eastwest strike-slip faults, which brought ascending hydrothermal solutions that led to clay formation and finally, the weathering processes have continued and extended the argillization