Provenance of Mid-Carboniferous Sandstones FromCounty Kerry, Ireland: Implications forPalaeodrainage and Landscape Evolution

Mid-Carboniferous sedimentary rocks in western Ireland have previously been extensively studied around the Shannon Estuary and on the County Clare coast, enhancing understanding of deep water, shallow-marine and coastal plain siliciclastic systems. This study shifts the focus southward to contemporaneous deltaic sandstones near Castleisland, County Kerry. A prove- nance study was conducted to establish sourcing of these sedimentary rocks with the objectives of a) improving palaeogeographic reconstruction; and b) comparing sediment supply to this part of the system versus that in the Clare Basin north of the Listowel High. Petrographic and heavy mineral analyses of the Scalpmore Sandstone (a time-equivalent of the Kilkee and Doonlicky deltaic cyclothems of the Clare Basin) reveal a recycled source and a textural difference in the sand supplied compared to Clare Basin sandstones. Published palaeoflow data, indicating flow from the west and new zircon U-Pb geochronology are consistent with derivation from the Upper Old Red Sandstone of the Dingle and Munster basins, with zircon ages matching those from the Upper Devonian of the Dingle and Iveragh peninsulas. Upper Devonian sedimentary rocks may have been exposed and available as a source at this time following Mississippian extension and footwall uplift and/or early onset (pre-Kinderscoutian) Variscan inversion of pre-existing structures. Although the Scalpmore Sandstone is time-equivalent to the Kilkee and Doonlicky deltaic cyclothems of the Clare Basin located c.45km to the north, contrasting detri- tal signals suggest different sediment routing and drainage scales: small-scale, single-sourced for Scalpmore Sandstone, versus large-scale and multiple source mixing for sandstones of the Clare Basin, north of the Shannon Estuary. This underscores the importance of careful sampling in provenance studies, as even stratigraphically and geographically adjacent sedimentary rocks may yield contrasting signals.