Reconstructing the Mesozoic–Cenozoic exhumation history of the Irish Sea basin system using apatite fission track analysis and vitrinite reflectance data

Abstract

This paper summarizes new and recent apatite fission track analysis and vitrinite reflectance results from across the Irish Sea basin system and its margins, which provide new constraints on the magnitude and timing of post-Palaeozoic exhumation across this area. In particular, these results suggest that this region has experienced a complex, multi-phase exhumation history. Distinct episodes of kilometre-scale exhumation occurred during the early Cretaceous, early Palaeogene and late Palaeogene–Neogene times, with the overall magnitude of exhumation in each episode decreasing over time. Regional early Cretaceous exhumation removed up to 3 km of section from the Irish Sea basins, and appears to be related to incipient Atlantic rifting. Early Palaeogene exhumation attained up to 2kmand was driven by a combination of localized tectonic inversion and regional epeirogenic uplift, although early Palaeogene palaeotemperatures within parts of the Irish Sea basin systemare dominated by non-burial-related processes. A final phase of exhumation, related to late Palaeogene– Neogene tectonic inversion, uniformly removed c. 1 km of section from this region. Given that these exhumation episodes coincide temporally with important periods of deformation at pre-existing or incipient plate boundaries, events at plate margins are interpreted to have exerted the primary control on the Mesozoic–Cenozoic exhumation of the Irish Sea basin system.