Fig. 9

External shapes and internal microstructures of 45 Asian dust particles collected in Korea, 18 Mar 2014. a Aggregates of clay minerals. b Large nonclay minerals coated with clay aggregates. c Composite of clays and nonclay minerals of varying sizes. Upper drawings: cross sections of the dust particles observed by TEM of FIB lamellae. Lower drawings: outlines of 2D particle shapes observed by SEM (dotted lines are traces of FIB slicing). Thin lines are 1-µm scale bars for FIB sections. Thick lines are 1-µm scale bars for SEM particle shape. White, gray, and dark gray areas of the particles in the upper drawings are pore, aggregates of clay minerals, and nonclay minerals, respectively. Minerals were identified by electron diffraction and energy-dispersive X-ray spectroscopy. Ab = albite, Afs = alkali feldspar (perthite), Amp = amphibole, Ant = anatase, Brk = brookite, Bt = biotite, Cal = calcite, Chl = chlorite, Dol = dolomite, Ep = epidote, Gp = gypsum, Gth = goethite, Ilt = illite, Kfs = K-feldspar, Kln = kaolinite, Mag = magnetite, Mgh = maghemite, Ms = muscovite, Pl = plagioclase, Qz = quartz, Rt = rutile, Spn = sphene (titanite), Vm = vermiculite