. . . "Old" . . . "Plateau Beds" . "old red sandstone" . "Red sandstone" . . "Upper Old Red Sandstone Group" . . . "Ballochmyle red sandstone" . . "Ffynnon Limestone" . . "Devonian sandstone" . "Senni Formations" . "Brownstones" . . . . . . . . . "Senni Formation" . . . . . "red sandstone" . "ashlar" . . "St Maughans Formation" . "sandstone" . . . "old red sandstone conglomerate" . . . . . . . . . . "Anglo-Welsh Basin" . . . . "Old Red Sandstone" . . "Brownstones Formation" . "History of study" . "Raglan Mudstone Formation" . . . . "red ashlar sandstone" . . . "pink sandstone" . . . "Quartz Conglomerate Group" . . "Old Red Sandstone" . . "local sandstone" . "Old Red Sandstone Supergroup" . . . "Anglo-Welsh basin" . . . "Raglan Mudstone" . . . "Breconian stage" .