Characterization of Palygorskite in dust of desertic provenance in aerosols, Sardinia, Western Mediterranean

Palygorskite aggregated grains occur in aerosol dust samples in western Mediterranean Sea. Morphology and texture of palygorskite grains was characterized analytical using SEM with attached X-ray energy dispersive system. Palygorskite occurs as rounded aggregate grains (wind-shaped), as interwoven fibrous mats forming fine laminae, and as porefilling and pore-bridging cements that commonly coat detrital grains and occur among them. The results show distinct and characteristic textures of palygorskite in dry (aerosol in air) and wet (precipitation) deposition. The main sources of this clay mineral are the dry rivers, lake beds, salt lakes, and argillaceous bed-rocks in northwestern Africa. Air mass trajectories calculation independently indicate two different source areas