EQ1 REVISION Flashcards
Igneous rocks
Are created by volcanic activity when magma or lava cools, forming rocks made of crystals that are usually hard. E.g. granite.
Metamorphic rocks
Are existing rocks that have been changed by extreme pressure or heat. They are usually comprised of layers or bands of crystals and are very hard. Examples of metamorphic include slate, which is compressed shale, or schists, which are formed from mudstone.
Sedimentary rocks
Are formed of small particles that have been eroded, transported, and deposited in layers, or from the remains of plants and animals. For example limestone and chalk.
Weathering process upland-the lake district
When the ground is rough, they are rock fragments, known as scree. Scree consists of angular rock pieces created by freeze thaw weathering. Each winter, temperatures are often below freezing at night and warmer during the day. Rainwater gets into cracks in the rocks, freezes, and expands by 10%. Expansion widens the crack, and eventually the rock breaks into pieces. Every winter adds more scree.
Slope processes-upland
Scree fragments are unstable and move easily during rock falls, increasing dangers for walkers.
Landslides are common. The lake district is the UK’s wettest region (over 2000mm of rain a year). Rain adds to the weight of weathered rock so it slides easily.
Slope processes affect valley slides.
Highest points-upland
978M Scarfell pike.
Geology-upland
Largely volcanic basalt (igneous) rock which erupted onto the surface 450-300mill years ago such as at Borrowdale. Also granite (igneous) erupted below the surface at Eskdale. These are both resistant. There is sedimentary rock present too when the UK was under tropical seas (350-250mill) such as mud and sandstone.
