Deep- versus shallow-marine sandstone provenance in the mid-Carboniferous Clare Basin, western Ireland

Abstract

In a source-to-sink sedimentary system, multiple processes have the potential to modify the sediment composition during sediment generation at the source, through transport, deposition and burial. To investigate these issues, a multi-proxy provenance study of deep-water and shallow-marine sandstones from the mid-Carboniferous Clare Basin was undertaken, utilizing zircon and apatite U–Pb geochronology, heavy mineral analysis (including apatite trace element data) and petrography. Data from the deep-water submarine fans show a similar provenance signal to the shallow-marine sandstones. Data from across the Clare Basin stratigraphy indicate that sands were probably and consistently derived from the south and SW, with a portion of the detritus being recycled from Old Red Sandstone basins to the south. The provenance signal, however, shows spatial and temporal variations across the basin that are explained by fluctuations in the amount of recycled sediments and are linked with the evolving Variscan Orogenic Belt. Heavy mineral data from both shallow-marine and deep-water sandstones suggest a basin configuration with a delta system feeding directly into the deep basin. Supplementary material: Figures S1–S4 and Tables S1–S8 are available at https://doi.org/10.6084/m9.figshare.c.5446739