These data are trace element concentrations and U-Pb isotope ratios from detrital apatite in Ordovician sandstones in Co. Mayo in western Ireland. UTM Sampling locations are also included, as are classifications of the likely lithology individual detrital apatite were derived from. Data were collected by LA-Q-ICPMS in the National Centre for Isotope Geochemistry in University College Dublin. Data were reduced using iolite 3 software.

X before sample number = DCFor U-Pb data, the very few blank analyses yielded no meaningful isotope ratios due to extremely low U or Pb#0.001 = LOD