geography : ROCKS (edexel B)

1. Igneous Rocks

🔥 Formed from cooled magma or lava

Texture: Hard, resistant, crystalline

Formation: When magma cools underground (intrusive) or lava cools above ground (extrusive)

Examples:

Granite (intrusive) - found in Dartmoor

Basalt (extrusive) - found in Northern Ireland (Giant's Causeway)

Landscape impact:

Forms highland areas (upland landscapes)

Resistant to erosion

Creates rugged features like tors and moorlands

2. Sedimentary Rocks

🌊 Formed from layers of sediment compressed over time

Texture: Softer, layered, may contain fossils

Formation: From compacted sediments (sand, mud, shells, etc.)

Examples:

Limestone - formed from marine organisms, alkaline

Chalk - softer, white, permeable

Sandstone - from sand grains, porous

Landscape impact:

Forms lowland areas

Creates features like valleys, cliffs, and caves

Chalk and limestone form dry valleys and karst landscapes (e.g., Yorkshire Dales)

🌋 3. Metamorphic Rocks

🔄 Formed when existing rocks are changed by heat and/or pressure

Texture: Hard, crystalline, often folded

Formation: From sedimentary or igneous rocks under intense heat/pressure

Examples:

Slate - formed from shale

Schist - formed from mudstones

Landscape impact:

Found in upland areas like Scotland

Very resistant to weathering

Slate splits into thin layers - used for roofing

📍 In the UK:

-North and West: Mainly igneous and metamorphic rocks → rugged, upland

-South and East: Mostly sedimentary → lowland, softer features