Constraining the provenance and thermal history of the Carboniferous Midland Valley of Scotland: Potential for energy resources

Situated between the Grampian Highland and Southern Uplands terranes, the Midland Valley terrane of Scotland is a Late Palaeozoic, WSW-ENE trending sedimentary basin, bound to the north and south by the Highland Boundary Fault (HBF) and the Southern Upland Fault (SUF) respectively. The basin evolved during a period of major tectonic plate reorganisation in the Late Palaeozoic, which also drove the Caledonian and Variscan orogenic events. Although Carboniferous coal seams have been extensively mapped in the basin due to their once economical importance, the provenance and post depositional thermal history of the Carboniferous detrital material, which have implications on the basins resource potential for unconventional exploration, geothermal resource, and hydrogen storage potential remain unknown. 

The use of zircon U-Pb geochronology to study the provenance of clastic sediment is well-established, yet the limited range of magmatic compositions from which zircon will crystallise, may over or under represent particular age populations (i.e. sediment sources) in the data. In this study, I will combine U-Pb LA-ICP-MS analysis of detrital apatite and zircon grains from the same samples, to better characterise the potential source rocks. The combination of these minerals will also help discriminate between polycyclic and first cycle sediment, providing insight on the palaeogeographic and palaeotectonic evolution of the region. 

Apatite fission track thermochronology will be applied to both outcrop and borehole sample across the Midland Valley in an attempt to constrain the post depositional thermal history of the sedimentary basin. The timing and extent of heating and subsequent cooling will provide valuable insight into the exhumation history of the basin and the magnitude of post-Carboniferous burial, if any. 

This multi-method approach to investigate the source to sink pathway and post depositional thermal history of the basin, will provide quantitative data on the basins evolution and aid better understanding of its resource potential.