 The island consists of varied geological provinces . In the far west , around County Galway and County Donegal , is a medium to high grade metamorphic and igneous complex of Caledonide affinity , similar to the Scottish Highlands . Across southeast Ulster and extending southwest to Longford and south to Navan is a province of Ordovician and Silurian rocks , with similarities to the Southern Uplands province of Scotland . Further south , along the County Wexford coastline , is an area of granite intrusives into more Ordovician and Silurian rocks , like that found in Wales . 
 The island <a href='uninflect' title='1'><mark>consists</mark></a> of varied geological provinces . In the far west , around County Galway and County Donegal , <a href='drop_aux' title='2'><mark>is</mark></a>a medium to high grade metamorphic and igneous complex of Caledonide affinity , similar to the Scottish Highlands . Across southeast Ulster and extending southwest to Longford and south to Navan <a href='drop_aux' title='3'><mark>is</mark></a>a province of Ordovician and Silurian rocks , with similarities to the Southern Uplands province of Scotland . Further south , along the County Wexford coastline , <a href='drop_aux' title='4'><mark>is</mark></a>an area of granite intrusives into more Ordovician and Silurian rocks , like <a href='null_relcl' title='5'><mark>that</mark></a>found in Wales . 
The island consist of varied geological provinces . In the far west , around County Galway and County Donegal , a medium to high grade metamorphic and igneous complex of Caledonide affinity , similar to the Scottish Highlands . Across southeast Ulster and extending southwest to Longford and south to Navan a province of Ordovician and Silurian rocks , w similarities to the Southern Uplands province of Scotland . Further south , along the County Wexford coastline , an area of granite intrusives into more Ordovician and Silurian rocks , like found in Wales .