GR 376939 469783 Nappa Scars. Looking W. Sub-Carboniferous unconformity. Thickly-bedded Dinantian conglomerates unconformably overlie steeply-dipping Norber (Upper Ordovician) mudstones. The basal Carboniferous conglomerate contains abundant Lower Palaeozoic pebbles and a few Carboniferous Limestone lithoclasts set in a carbonate matrix. BGS