Here, we present zircon geochronology and tephra/glass compositions from four explosive Pleistocene eruptions of the Atitlán caldera in Guatemala. Our datasets encompass zircon 238U-230Th disequilibrium, U-Pb, and (U-Th)/He geochronology, analyzed using a CAMECA IMS 1280-HR secondary ion mass spectrometer (SIMS) at Heidelberg University, Germany, alongside noble-gas and inductively coupled plasma mass spectrometry (ICPMS) at Curtin University, Australia. Major and trace element compositions of glass shards were determined through electron microprobe analysis (EMPA) at GEOMAR - Helmholtz Centre for Ocean Research Kiel and by laser ablation ICPMS at the Institute of Earth Sciences, Academia Sinica in Taipei. Whole-rock U-series analyses were carried out using a ThermoFisher Neptune multi-collector ICPMS at the University of Wyoming (UWYO, USA).

Analytical Uncertainties are 1σ. ∞ = zircon in secular equilibrium (˃350 ka) m = zircon-melt model isochron slope; (238U)/(232Th) = 0.983 ± 0.009 and (230Th)/(232Th) = 1.072 ± 0.026 from this study. Decay constants used: λ232: 4.9475·10−11 a−1; λ230: 9.1705·10−6 a−1; λ238: 1.55125·10−10 a−1. Secular equilibrium zircon reference AS3 (230Th)/(238U)= 1.001 ± 0.006 (MSWD = 0.56; n= 19) for session where new samples were analyzed (G13-87, PET-06, M6613-229, M18-1). U concentration from measured 238UO+/90Zr2O4+ relative to 91500 zircon with 81.2 ppm U. Rows with different gray color represent multi-dated grain interiors.