Project title: Regional variations in Carboniferous lithofacies and their links to basin and structural evolution within the Irish Zn-Pb Orefield.
Researcher: Rob Doyle
As mineral exploration is getting increasingly deeper, there is a critical scientific and societal need to better understand the distribution of the Carboniferous lithostratigraphic units in space and through time. The interplay between the evolution of the fault systems and the deposition and juxtaposition of suitable host rocks is important for Zn-Pb mineralising systems in the Irish Orefield, as well as for identifying groundwater and geothermal reservoirs.
The use of 2D reflection seismic in Ireland has been a game-changer, providing improved targeting for mineral and deep geothermal exploration and new insights into basin evolution. However, there is a need to better understand the lateral changes in reflectivity seen for example in the seismic, especially in the deeper basinal sequences, and even more so in sediments deposited in the post-rift thermal sag phase. Not much is understood about the evolution of the sedimentary architecture of the basinal syn- and post-rift sequence, but since exploration drilling and seismic routinely encounter these units this project is designed to capitalise on the associated deep drilling constraints. In general, an up-to-date regional picture of lithofacies variation through time is lacking and up-to-date, higher accuracy lithofacies models are needed to better predict what facies is likely to be present at a given location, for the correct time interval. An up-to-date picture of the evolution of the sedimentary basin infill and subsidence is also missing. Aims & Objectives:
(i) Investigate the principal regional lithofacies variations in the Irish Mississippian Carboniferous through time, the extent to which this is punctuated by the evolving fault kinematics, and how it links to the development of Carboniferous (sub)basins.
(ii) Provide insights into the basic principles behind lithofacies distribution in the carbonate basin using the best available examples and datasets.
(iii) Create models of the pre-/syn- to post-rift thermal sag phase carbonate sedimentation, and provide general insights into the degree to which faulting affects carbonate sedimentation.