112 A Field Guide to the Carboniferous Sediments of the Shannon Basin, Western Ireland, First Edition. Edited by James L. Best and Paul B. Wignall. © 2016 International Association of Sedimentologists. Published 2016 by John Wiley & Sons, Ltd. Companion website: www.wiley.com/go/best/shannonbasin Architecture of a Distributive Submarine Fan: The Ross Sandstone Formation DAVID R. PYLES & LORNA J. STRACHAN Chapter 7 7.1 Introduction to the Ross Sandstone Formation The Namurian Ross Sandstone Formation crops out on sea cliffs and wave‐ cut platforms of the Loop Head Peninsula, County Clare and near Ballybunnion, County Kerry (Figs 7.1.1 and 7.1.2). The formation contains some of the most laterally continuous exposures of turbidites to be found anywhere, and is an excellent outcrop analogue for distributive submarine fans, which form important oil and gas reservoirs around the world. The Ross Sandstone Formation has attracted considerable attention due to its use as an analogue for turbidite hydrocarbon reservoirs, and the chapter begins with an overview of the geological setting of the Formation, together with its lithofacies and main characteristics. This summary provides the background from which the Ross Sandstone Formation outcrops are then detailed. The excursions described in this chapter provide an opportunity to visit the principal outcrops of the Ross Sandstone Formation and exam- ine the wide array of sedimentary structures and facies that comprise this beautifully exposed ancient distributive submarine fan. Geologic setting Biostratigraphy The biostratigraphic zonations of Namurian strata of western Ireland were defined by Hodson (1954a,b), who identified thin (< 1.0m thick), black, goniatite‐bearing, organic‐rich shale beds in north County Clare (Fig. 7.1.3) and termed them “marine bands”. Hodson (1954a, b) recog- nised that successive marine bands contain a unique goniatite assemblage