GCSE Geography Edexcel B Paper 2 : ROCKS AND GEOLOGY

Describe freeze-thaw weathering

involves water getting into a gap in the rock and then freezing when the temp drops, water expands as it freezes and this puts pressure on the rock, the ice melts and more water enters the now larger gap and freezes , this repeats until the rock eventually breaks

Describe biological weathering

- plant roots can penetrate into rocks over time, causing the rock to break apart

- animals walking over the rocks can also weather them over time

- anything living that wears away the rock really

describe chemical weathering

- rainwater is naturally acidic, CO2 dissolves in it to give carbonic acid

- weathering by chemical processes such as acid rain

Sedimentary rocks

- layers of sediment deposited over time gets squashed together to form new rocks eg. sandstone, limestone, chalk

- Characteristics : permeable, less resistant to erosion, has many layers

How are igneous rocks formed?

- Formed when molten magma cools slowly, forming crystals, the crystals are larger if the rock cools more slowly eg. granite, obsidian, basalt

- Characteristsics : impermeable + resistant to erosion

Metamorphic rocks

a rock that has been changed by extreme heat and pressure, no holes or fossils, smooth eg. slate and schist

what landscapes does igneous rock such as granite create?

- forms upland landscapes as it's very resistant to erosion

- it is impermeable so it doesn't let water through creating moorland, areas with waterlogged land and acidic soil

where are upland areas found in the uk

They are mostly found in the north and west of the UK.

where are lowland areas found in the uk

south and south east of england

examples of an upland area in the UK

- Grampian mountains and northwest highlands in Scotland

- The penines in england

what landscapes does chalk create?

- forms lowland landscapes as it's not resistant to erosion

- forms cliffs at coastlines

- water flows through it and emerges as a spring where it meets impermeable rock

what landscapes does clay create?

- found in most of the UK

- wide landscapes, flat plains with lots of drainage

what landscapes does carboniferous limestone form?

as rainwater eats away at the limestone through carbonation weathering, most weathering happens at joints in the rock creating limestone pavements

where does the mersey river flow?

through manchester and liverpool

what are the ways that tectonic processes have shaped the uk landscape?

- active volcanoes - they formed magma through the earth's crust which cooled to form igneous rocks

- plate collisions - caused the rocks to become folded and uplifted forming mountain ranges, and the intense heat and pressure caused by plate collisions formed hard metamorphic rock

how have glacial processes affected the uk landscape?

- the ice eroded the landscape through abrasion ( eroding the sides of the landscape) and freeze thaw weathering carving out large u shaped valleys (they were originally V shaped) in upland areas such as the Lake district

- glaciers deposited lots of material as they melted, large parts of eastern england are covered in till (an unsorted mixture of clay, sand and rocks)

what are the four physical prcoesses that alter landscape?

- weathering = the breakdown of rock into smaller pieces it can be mechanical, chemical or biological

- erosion = wears away rock, during the last glacial period ice eroded the landscape, rivers and sea now constantly erode the landscape

- post glacial river processes = melting ice at the end of the glacial periods made rivers much bigger than normal with more power to erode the landscape

- slope processes = including mass movements and rockfalls

how has human activity affected the uk's landscape?

- sheep farming takes place in the harsher conditions in the uplands, sheep farming leads to a lack of trees on the hills

- forestry, the uk used to be covered in deciduous woodland however now there's very little natural woodland left, coniferous forests have been planted for timber the trees are planted in straight lines so they don't look natural and when the areas are felled they look bare

- settelments, land was concreted over for roads which affected drainage patterns, some rivers were straightened or had embankments built to prevent flooding

- hedgerows and walls/field margins have been installed to mark out field boundaries

Case study of an upland area : The Lake district overview

- made of igneous rocks

- some U shaped valleys have filled with water while others have misfit rivers

- lots of tourism main contribution to lake district's economy

Case study of an upland area : The lake district weathering and slope processes

- covered in scree due to freeze thaw weathering

- high rainfall leads to landslides

Case study of an upland area : The lake district post glacial river processes

- glaciers eroded the sides of landscapes to form U shaped valleys

- these hollows are now filled with lakes and misfit rivers

Case study of a lowland area :The Weald overview

- gently rolling hills in sussex and kent, along with infertile soils at the top of hills and wet sticky clay means crop farming is difficult

- once a dome of tectonically folded rock

- erosion has left alternate strata of more resistant chalk

Case study of a lowland area : The Weald post glacial river processes

- during and after the last ice age, water in the chalk froze, making it impermeable and eroded by rivers, but now permeable again leaving dry valleys

Case study of a lowland area : The Weald weathering and slope processes

- the most common slope process is soil creep