4a - UK’s Physical Landscape Flashcards
State the three rock types
Igneous, metamorphic, sedimentary
How are igneous rocks formed and give examples?
Igneous rocks are formed when volcanoes erupt and the magma cools, and they are crystalline & hard eg granite
How are metamorphic rocks formed and give examples?
Metamorphic rocks are formed when other rocks are changed by extreme pressure and heat, and they are crystalline and hard eg shale, schist
How are sedimentary rocks formed and give examples?
Sedimentary rocks are formed when layers of sediment are compacted together until they become solid rock eg chalk, clay, carboniferous limestone
What are the features of the north & south west of the UK?
- Mainly igneous and metamorphic rocks as a result of being closer to tectonic plate margins in the past, which are more resistant to erosion
- Upland relief
- Wetter, cooler climate
- Lower population density
What are the features of the south east of the UK?
- Mainly sedimentary rocks which are less resistant to erosion, often permeable
- Lowland relief
- Warmer, drier climate
- High population density
Explain the why the climate of the north & south east of the UK arises?
- wetter climate caused by relief rainfall where air is forced to rise over higher land, where it is colder, cools and condenses to form clouds which release rain
- colder as temperature declines with altitude as air rises, expands and cools
- sometimes snow in the uplands as there is lower temps meaning precipitation sometimes falls as snow and not rain
How has tectonic activity shaped the UK upland landscape?
- past continental collisions created lots of heat and pressure turning the igneous and sedimentary rocks into metamorphic rock
- due to extrusion, volcanoes erupted and igneous rocks formed from cooling magma which created areas of high relief
- plate collisions caused rocks to be folded and uplifted, forming mountain ranges which are now mostly upland areas
Describe 2 forms of glacial erosion
Abrasion - where the moving glaciers eroded valleys by widening them
Plucking - the ice of the glaciers freezes to the sides and bottoms of valleys, plucking material away and transporting it elsewhere
How has glaciation affected the upland UK landscape?
Moving glaciers eroded valleys by widening and deepening them through plucking (ice plucks fragments away) and abrasion (sandpaper effect of fragment scraping) which has resulted in U-shaped valleys
Describe the isostatic change during and after the ice age
During - The north was glaciated with the weight of the ice forcing it to sink but the south wasn’t glaciated so was forced to rise
After - Glaciers in the north melted so the North began to rise relative to sea level causing the south to now sink relative to sea level
What is eustatic change a result of?
Eustatic change is a result of thermal expension of sea water and melting of terrestrial glaciers causing rising sea levels
How was geology caused lowland landscapes?
Causes springs
Precipitation falls on permeable chalk escarpment
Water infiltrates the permeable chalk saturating it,
Water flows downhill until it reaches the impermeable clay where it is forced to the surface causing a spring
How has tectonic activity affected the lowland UK landscape?
Tectonic activity forced the beds of chalk upwards forming an arc
The exposed parts eroded leaving behind chalk escarpments with steep scarp slopes and gentle dip slope.
How has glacial processes affected lowland UK landscapes?
During Ice Age, permafrost covered periglacial environment
Precipitation was unable to infiltrate and flowed in rivers over the land
The rivers erodes V-shaped valleys through vertical erosion
After the Ice Age, water infiltrated into the chalk leaving dry valleys
