Rocks

Rocks are classified… …...According to formation –Igneous – volcanic material –Sedimentary – compressed remains –Metamorphic – changed by heat/pressure

Igneous Rocks Formed when magma (lava) cools and solidifies. Most common Igneous rocks include Granite and Basalt. Granite Basalt

Igneous Granite Hard, coarse, multi coloured Cooled magma inside earth Wicklow Mtns Basalt Heavy, black Lava cooled on surface Giants Causeway

Granite – Mount Rushmore Basalt – Giant’s Causeway

Sedimentary Rocks Formed when the remains of dead sea creatures and plants build up in layers. They get compressed and cemented together over time. Most common include Limestone and Sandstone. Limestone Sandstone

Sedimentary Sandstone Coarse, brown, red Compressed sand grains Magillicuddy Reeks Limestone White/grey Compressed fish remains/skeletons The Burren

Limestone Strata (layers) Horizontal bedding planes Vertical joints Permeable (water seeps through) Easily weathered Contains fossils

Metamorphic Rocks Formed when either Igneous or Sedimentary rock is put under great heat or pressure. Marble Quartzite

Metamorphic Marble Hard, crystal White, green, red, black Limestone changes to marble through heat or pressure Connemara

Key Words Strata: a horizontal layer in rock or soil, sometimes called bedding planes. Joint: a vertical crack in rock. Permeable: allows water to pass through. Porous: holds water and allows it to pass through. Fossil: the preserved remains of a plant or animal.

Extraction industry Shaft mining – underground, for lead and coal Offshore drilling – for oil + gas Open cast mining + Quarrying – surface, for stone, sand, gravel and peat