Geological, Physico-Chemical Characterization and Estimation of Clay Reserves Exploited in Pottery in Draa-Tafilalet Region (Morocco)

Investigations carried out on pottery in the Draa-Tafilalet (DT) region have shown that this activity is subject to many constraints linked particularly to the depletion of natural resources, lack of workforce, and the quality of the final products. This study contributes to the recognition, characterization, and valuation of clay materials in the DT region in order to control a sustainable supply for local potters. To do this, various analyses are carried out, particularly at the lithological, mineralogical, chemical, and technological characteristics of the clays exploited in pottery, as well as data relating to the estimated reserves in the supply zones. The clays are harvested in different geological contexts from four provinces covering different Saharan structural domains. The analyses generally show a loamy to sandy-loamy composition with a clay fraction not exceeding 14%. Most materials have a plastic character (15 < PI < 40). The identified minerals are dominated by quartz, total clay, goethite, calcite and feldspars. The clay fraction is composed of illite, chlorite, kaolinite, smectite, and palygorskite. The collected data are processed in chemical, mineralogical and granulometric diagrams to test the suitability of these materials for use in ceramics. Medium-quality samples were balanced in formulations to improve their pottery making ability. It shows that, despite qualitative fluctuations, DT clays can be used in pottery, subject to adjustments relating to manufacturing processes and firing conditions. The amount of clay consumed annually by potters remains very modest (~ 3000 tons/year) compared to potential clay reserves estimated at 30 million tons.