THE COMPOSITION OF CLAY-MINERALS TRANSPORTED TO ISRAEL AS INDICATORS OF SAHARAN DUST EMISSION

Ambient particles, following dust storms originating in the Saharan region as identified by meteorological analysis of synoptic maps, satellite pictures and back-trajectory calculations, transported over Israel, were collected and analysed. In studies of 28 heavy dust storms originating in the Saharan region, during a 22 year period (1967-1988), clay mineral analysis provided information about the characteristics of dust particles transported over Israel. Relatively high concentrations of montmorillonite and mixed-layer minerals were found in the particles when the storms originated on the western deserts of the Tibesti mountains. Following storms that originated in Saudi Arabia, Jordan and the Dead Sea deserts, the dust particles contained a high percentage of palygorskite. Following storms that originated in the Chad, Lybian plateau deserts and the Great Sand Sea of Ahaggar Massif, predominantly high concentrations of illite was found in the ambient particles in Israel. These data indicate that ambient particles in Israel following dust storms originating in the Saharan region may be characterized by their mineral content.