trajectoire (1) sédiment (1) pluie (1) mélanger (1) minéralogie (1) matériau (1) analyse (1) gypse (1) Europe (1) environnement (1) poussière (1) nuage (1) Europe (1) Composition (1) Specimens (1) Sodium sulfate (1) Spring (1) Smectite (1) Sahel (1) Sahara (1) Rainstorms (1) Rain and rainfall (1) Quartz (1) Possibility (1) Palygorskite (1) Nature and nurture (1) Mixing (1) Mineralogy (1) Kaolinite (1) Illite (1)