Grain size distributions were determined in volcanic ash samples using a Malvern Mastersizer 2000 particle analyser, equipped with a laser diffractometer (ultrasonic water disaggregation: Hydro MU system; absorption: 0.1; refractive index: 1.52; measurement time: 20 s; obscuration: 10–20%; and pump speed: 2500 rpm, 3 measures), following the recommended procedures of the International Volcanic Health Hazard Network (IVHHN, www.ivhhn.org). This technique measures particles of 0.1–1000 μm using the Mie Theory; due to this limitation, only distal ash samples with maximum grain sizes of < 1 mm for the complete deposit (not grain fractionated) were analysed. The particle-size abundance is reported as the volume percentage of equivalent spherical diameter. Contact person: Fernandez-Turiel, J. L., jlfernandez@ictja.csic.es

This dataset includes particle size distribution data of volcanic ashes of Southern Puna and neighbouring areas (NW Argentina). The content of particles of 0.1–1000 μm was determined by lasser diffraction. The studied volcanic materials are mainly associated with the 4.2 ka cal BP eruption of the Cerro Blanco Volcanic Complex. Some samples area related to the Cueros de Purulla volcano.

MINECO, CGL2011–23307

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