This dataset includes results from U-series and Sr-Nd whole-rock isotope compositions of the last four explosive silicic eruptions from Ilopango caldera in El Salvador (TBJ, TB2, TB3, and TB4). Sr and Nd isotope ratios were measured with a Nu Instruments thermal ionization mass spectrometer (Nu-TIMS) at Departamento de Geología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) in the state of Baja California (Mexico), whereas U and Th concentrations and isotopes were measured at University of Wyoming (UWYO) were measured by isotope dilution using a ThermoFisher Neptune ICP-MS multicollector.

Activity ratios calculated using decay constants of 9.1577 x 10-6 a-1 for 230Th (Cheng et al., 2000), 4.9475 x 10-11 a-1 for 232Th (Le Roux & Glendenin, 1963), 2.8263 x 10-6 a-1 for 234U (Cheng et al., 2000), and 1.55125 x 10-10 a-1 for 238U (Jaffey et al., 1971).BCR-1, TML, AGV-2: relative to reference values from Scott et al. (2019).