Title: Determining the Mesozoic–Cenozoic thermal history of the Irish offshore basins and the Irish mainland
Researchers: Dr Claire Ansberque and Dr David Chew
This project seeks to determine the Mesozoic-Cenozoic thermal evolution of the Irish mainland and its offshore basins. The post-Variscan evolution of the Irish landmass and its offshore basins is characterized by a series of diachronous rifting and subsidence events punctuated by repeated episodes of exhumation variously attributed to phases of rift-shoulder uplift, magmatic underplating related to hotspot activity and compressional inversion. These phases of exhumation have controlled not only the present-day physiography but also the distribution and prospectivity of hydrocarbon resources. However determining the post-Variscan geological evolution of Ireland is hindered by the paucity of Mesozoic/Cenozoic onshore outcrop and the truncated stratigraphic record in many of the inboard basins. Hence geoscientists must employ indirect methods for the assessment of exhumation (e.g. thermal history modelling using low-temperature thermochronometers) to constrain the Mesozoic-Cenozoic exhumation history. Quantifying the onshore erosion of Ireland allows to constrain when and where offshore deposition occurs, representing a valuable source of information for basin development and hence for hydrocarbon exploration
Previous work showed a Paleogene uplift phase in link with the Icelandic plume (Cogne et al., 2016), which dissipates towards the western coast of Ireland where uplift occurred earlier in the Jurassic and Cretaceous (Cogne et al., 2015). The samples newly collected in SW Northern Ireland (boreholes) will likely be in the line of the results obtained on the western coast of Ireland, but may slightly diverge due to the presence of numerous faults in this area.
- Thermal history modelling: Synthesize all existing data on the thermal history evolution of the Irish mainland and offshore basins; Characterise the thermal history evolution of the Irish offshore basins and offshore basin highs.
- Analytical developments: Developing sintered pressed-powder pellets standards for LA-ICPMS apatite trace-element analyses.