Basin inversion controls on diagenetic evolution of Lower Cretaceous non-marine succession: the English Wealden sandstones

Abstract

Modelling the diagenetic history of a tectonically active basin is crucial for understanding the depositional and post-depositional processes including the evolution and development of porosity and permeability. This study describes the diagenetic imprints of the inverted Lower Cretaceous Weald Basin and examines the depositional and tectonic controls on the diagenetic, porosity and permeability evolution of its sandstones. Seventy-two representative sandstone samples from the Weald Basin were subjected to detailed microscopic (optical and scanning electron) analyses. The dominant early diagenetic fabrics include grain-coating detrital clays, degraded and dissolved detrital grains, and vermiform kaolinite pore-filling cement while uplift-related or telogenetic characteristics are mainly post-compactional pore-filling goethite and hematite cement. This work is significant because it presents the first diagenetic model of the Lower Cretaceous Wealden sandstones which can be very useful for understanding basins with similar depositional and tectonic settings.