Fold Mountains in Ireland

Three periods of folding; The Caledonian (oldest), Armoricain (younger), and Alpine (youngest)

  1. Caledonian

    • 400-350 million years ago

    • Occurred when the Eurasian and North American plates collided

    • During the Silurian Geological period

    • Folds are in a Southwest to Northeast trend

    • Collision was so intense that magma intruded and formed igneous and metamorphic rocks

    • Originally taller than the Alps (5000m), but have been worn down by denudation. As a result, the metamorphic and igneous rocks have become exposed

    • Found in the west, north west and east. (Maamturk, Bluestack, Dublin), in Scotland and in America

  2. Armorican

    • 250 million years ago

    • Permian geological period Folds are

    • Occurred when the Eurasian and African plates collided During

    • Folds are in an East to West trend Collision was

    • Collision not as severe. However, anticlines and synclines were still formed

    • Formed the ridge and valley landscape of the south (Macgillycuddy reeks, Comeragh and Galtee)

    • Denudation has exposed the old red sandstone

    • Part of the larger Hyrcanian Orogeny 

  3. Alpine

  • 30 million years ago

  • Eurasian and African plates collided in a different place

  • Responsible for the Alps, the Rockies, the Himalayas, and the Andies

  • Didn’t affect Ireland