We investigate the utility of the U-Pb isotopic system as a thermochronometer for the accessory phase apatite and its potential to yield continuous time(t)-Temperature(T)-paths over long geological timescales (>100 Ma). The apatite U-Pb thermochronomter has recently been proven to recover meaningful continuous t-T history, resolving reheating events from isothermal holding, solutions based on the principle of thermally activated volume diffusion. Several data sets involving apatite U-Pb bulk grain data however document scatter beyond that predicted by thermally activated volume diffusion and this thesis aims to address the nature of these observations. A new isotopic and geochemical dataset is established, which includes 1) ID-TIMS single grain apatite U-Pb dates, 2) LA-ICP-MS element maps, 3) LA-MC-ICP-MS U-Pb date profiles of selected apatites, 4) LA-ICP-MS U-Pb dates of zircon, 5) 40Ar/39Ar dates of white micas, to investigate the effect of parent isotope zonation and composition in diffusion studies.