An anomalous atmospheric dust deposition event over CentralEurope, 24 March 2007, and fingerprinting of the SE Ukrainiansource

An anomalous event of Ukrainian quartz-dominated dust deposited in the Czech Republic and adjacent countries on 24 March 2007 was studied with special emphasis on sedimentology, mineralogy and geochemistry. The dust deposition combined a typical eolian depositional mode with one mediated by dirty rain or drizzle. The main stage of sediment deposition was short (several tens of minutes) and synchronous with rapidly increased concentration of particles smaller than 10 microm in the atmosphere above ground. The polydisperse and multimodal sediment consisted predominantly of angular to subrounded quartz particles, of which 80-90 wt.% were silt sized (4-63 microm). A small amount of sand grains up to 0.5 mm in size was regularly observed (<10 wt.%) and was higher than that of particles smaller than 4 microm. This relatively coarse material was transported by atmospheric flows over distances of 1400 to 2000 km.