Each year, huge quantities of silt-sized (<63 & micro;m) sediments are emitted from the Sahara and transported all over the world. Reconstruction of air circulation and identification of source area(s) are the key issues in aeolian research. Here, we propose a microtextural analysis of dust-forming silt grains as an effective tool for reconstructing the source(s) of airborne sediments and the formative processes of silt grains. We analyzed more than 1,000 grains collected in different locations in the Iberian Peninsula during the extreme dust storm that occurred between March 14 and 18, 2022. The examination using a scanning electron microscope included determination of the grain size, recognition of the general appearance of grains (microtextures), their shape and degree of encrustation. HYSPLIT and MONARCH models were used to track the air circulation of the studied event. The studied samples show different microtextural composition, i.e. various proportions of grains with fresh, etched, encrusted and/or cracked surfaces. The results suggest that the majority of the sediments carried in the studied dust storm originated from the alluvial and paleolakes deposits. Considering the distribution of such deposits in the Northern Sahara, we conclude that dust emissions from areas located south of the Northern Sahara must have actively contributed to the studied event. These are, in particular, areas located in the Sahel Zone, mainly in its northern part-Chad, Niger, Mali, and Mauretania. Dust emitted from the Sahel zone mixed at higher altitudes with dust emitted from the Northern Sahara, and traveled as a heterogenous dust plume.