The provenance of Middle Jurassic to Cretaceous sediments in the Irish and Celtic Sea Basins: tectonic and environmental controls on sediment sourcing

Abstract

The Jurassic and Cretaceous sedimentary infill of the Irish and Celtic Sea Basins is intimately associated with the breakup of the supercontinent Pangea, and the opening of the Atlantic margin. Previous basin studies have constrained tectonism, basin uplift and sediment composition, but sediment provenance and routing have not received detailed consideration. Current hypotheses for basin infill suggest localized sediment sourcing throughout the Jurassic and Cretaceous, despite a dynamic tectonic and palaeoenvironmental history spanning more than 100 million years. We present detrital zircon, white mica and apatite geochronology alongside heavy mineral data from five basins. Findings reveal that basin infill derived predominantly from distal sources with lesser periods of local sourcing. We deduce that tectonically induced marine transgression and regression events had a first-order control on distal v. proximal sedimentary sourcing. Additionally, tectonism which uplifted the Fastnet Basin region during the Middle–Late Jurassic recycled basin sediments into the connected Celtic and Irish Sea Basins. Detrital geochronology and heavy mineral evidence support three distinct provenance switches throughout the Jurassic and Cretaceous in these basins. Overall an integrated multi-proxy provenance approach provides novel insights to tectonic and environmental controls on basin infill as demonstrated in the Irish and Celtic Sea Basins. Supplementary material : Tables S1–S6 are available at https://doi.org/10.6084/m9.figshare.c.5343657