Atmospheric dust particles actually comprise a small number of mineral assemblages. We determined the composition of these assemblages and their geographic distribution by statistical analysis of mineralogy data. Air mass trajectory analysis was used to identify transport paths and possible source regions for these samples. Three types of trajectories are most common, and each displays different proportions of four mineral assemblages. The first indicates outflow of air from central Asia and is associated with an illite-rich mineralogy. The second type comprises trajectories which include low-altitude transport over the Japanese islands, for mixed mineralogies which contained a small amount of the illite-rich end-member. The third type is made up of trajectories crossing the North American continent and is present exclusively in the eastern North Pacific area. There is a mixed mineralogy associated with these trajectories. Our results suggest that both source area mineralogy and transport pathway contribute to the compositional variability of the mineral aerosol at a given location. The results presented here show that event-specific meteorological data can be useful in understanding spatial patterns of eolian transport. ¿ American Geophysical Union 1994