Subsidence and erosion in the Pennine Carboniferous Basin, England: lithological and thermal constraints on maturity modelling

Forward modelling of maturity against vitrinite reflectance and chemical da ta for a number of onshore boreholes was used to test a range of subsidence and thermal histories for the Pennine Carboniferous Basin. The preferred m odels suggest maximum palaeotemperatures were reached during late Cretaceou s or possibly early Tertiary burial, consistent with the outcome of previou s apatite fission-track studies. Models in which maximum palaeotemperature was attained in the late Carboniferous are considered less likely: rapid bu rial under a normal heat flow requires an unrealistic thickness of missing late Westphalian strata, whilst high regional heat flow is incompatible wit h the observed vitrinite reflectance gradients. The lithologies assumed for missing strata have a significant influence on the range of estimates of e roded thicknesses. Preferred estimates of Cenozoic erosion range from aroun d 1.6 km in Mesozoic basinal areas to around 2.8 km within areas of present Carboniferous outcrop.