Geochemical analysis of tephra layers T1-T6, from Salar Grande site (20°59.862'S, 70°01.630'W). These data complement and support the results presented in the journal article "Identification of humid periods in the Atacama Desert through hillslope activity established by infrared stimulated luminescence (IRSL) dating". Medialdea et al., 2019. Global and Planetary Change.

Glass shards from the six volcanic ash horizons (T1-T6) interbedded in the investigated profile were concentrated from the samples by sieving 125 µm, magnetic separation (FRANTZ), and density separation 2.3-2.5 g.cm-3. Glass concentrates were mounted on epoxy pucks, polished, and subsequently carbon coated prior to analysis. The elemental composition of individual glass shards and secondary reference materials Lipari obsidian (Kuehn et al., 2011) and MPI-DING ATHO-G reference rhyolitic glass (Jochum et al., 2006) is determined by wavelength-dispersive electron probe microanalysis (EPMA). Analyses were conducted using a JEOL JXA-8900RL EPMA at the University of Cologne equipped with a five-wavelength dispersive spectrometer, which was set to 12 keV accelerating voltage, 6 nA beam current, and 5 µm beam diameter, respectively. Elemental compositions are normalized to 100% anhydrous and volatile-free totals (Cl, SO3, and F). Full details on the analytical results can be found in the table.