 The island consists of varied geological provinces . In the far west , around County Galway and County Donegal , is a medium to high grade <unk> and igneous complex of <unk> affinity , similar to the Scottish Highlands . Across southeast Ulster and extending southwest to Longford and south to <unk> is a province of Ordovician and <unk> rocks , with similarities to the Southern <unk> province of Scotland . Further south , along the County Wexford coastline , is an area of granite <unk> into more Ordovician and <unk> rocks , like that found in Wales . 
