Flashcards in Changing That Landscape Of The Uk Deck (31):
What are sedimentary rocks?
Sedimentary rocks are formed of small particles that have been eroded, transported, and deposited in layers, such as sandstone; or from the remains of plants and animals, for example limestone and chalk
What is chalk?
It a type of sedimentary rock that is made up of calcium carbonate, and is susceptible to chemical weathering
What is sandstone?
It's a type of sedimentary rock that is made up of sand-sized grains cemented together. It can be hard and resistant to weathering but is permeable
What is igneous rock?
Igneous rocks are created by volcanic activity when magma or lava cools, forming rocks made of crystals that are usually hard. Examples are granite and basalt
What is granite?
It's a type of igneous rock that is affected by chemical weathering. Granite landscapes drain badly, so tend to be boggy
What is basalt?
Basalt is a type of igneous rock that is grey made from very small crystals. Lava flows and cools to form basalt
What is metamorphic rock?
Metamorphic rocks are formed from other rocks changed by extreme pressure or heat. They are usually formed from layers or bands of crystals and are very hard. Examples of metamorphic rock include shale that is compressed into slate, or limestone that is transformed into marble
What is the geology of the Uk upland? (Describe the igneous and metamorphic rocks)
Upland areas are formed of harder resistant rocks which have eroded at a much slower rate. These include the igneous and metamorphic rocks found in Scotland, north wales, the Lake District and parts of south - west England. Around 300 million years ago tectonic processes caused molten magma, under intense pressure to rise through the earths crust. Some magma reached the surface of lava - whilst some magma cooled and solidified underground. Today these are high areas of relief example Dartmoor in Devon
Millions of years ago the uk was close to plate boundaries. Plate movements caused mountains (huge folds) and faults in the rocks. 520 million years ago two plates converged to form upland mountain landscapes - northern Scotland, the Lake District and north wales. 50-60 million years ago diverging plate boundaries cause the Atlantic Ocean to open. Rising lava produced the distinctive basalt geology of the Giants causeway
North-west of the Tees-Exe line the UK's geology is largely igneous: rocks formed from magma and lava, associated with tectonic events. Long-extinct volcanoes form hills and mountains.
Basalt can form a very distinct landscape as the lava cools into polygon shapes: for example, the giants causeway in Northern Ireland and Fingal's cave in Scotland.
Glacial erosion? (Upland)
Stickle tarn, in the north, is where a glacier formed during the ice age and carved out a corrie
The crags are exposed rock faces. Weathering leads to rock fragments breaking off and falling to the base of the cliff to form a scree slope
High precipitation here means there is a lot of surface drainage over the impermeable rocks; there are many streams
Post-glacial river? (Upland)
The valley floor at the bottom is too wide for the stream to have eroded it. The flat bottom and steep sides shows that it is a U-shaped valley formed by a glacier
River erosion? (Lowland)
As the rivers meander, they have eroded a wide valley between low hills. The rivers transport slit eroded from the river channel
River deposition? (Lowland)
Prolonged heavy rain can cause the rivers to flood. Water so reads out all over the valley floor, depositing the slit to form a wide fat floodplain
What is Forestry?
Forestry is managing woodland for timber
Many uk upland landscapes have been planted with trees for forestry. Sometimes they are in straight rows to make them easy to manage
The uk would naturally be covered by deciduous woodland. However, some uk landscapes feature conifer plantations, which are distinctive
What are the 3 main uk rock types?
What is the geology of the UK upland? (Describe sedimentary rocks)
Some upland areas are also formed of harder sedimentary rocks. An example Carboniferous limestone, formed 250-350 million years ago when Britain was surrounded by warm tropical seas rich in plant and animal life. When the plants and sea creatures died, the calcium in their shells and skeletons built up layers on the sea bed, forming limestone made from calcium carbonate
What is the geology of the uk lowland?
Many lowland landscapes are formed from softer, younger sedimentary rocks which are less resistant to erosion. Examples are the north and South Downs in south east England. These hills are formed of chalk, with even softer clay in the valleys between them
How did tectonic processes help shape the geology and landscapes of today?
Millions of years ago, Britain was much closer to plate boundaries than today. There were many active volcanoes, and plate movements caused massive folds and faults in the rocks
What is Dartmoor an example of?
Of an upland landscape formed when a massive dome of magma developed underground 290 million years ago. As it cooled and contracted to form granite, cracks known as joints developed. The presence of the weaker joints made the rock vulnerable to freeze thaw weathering where repeated freezing, expanding and thawing of water causes fragments of rock to become detached. Over time as the granite became exposed on the surface, erosion and mass movement processes like slumping removed the broken up granite. Blocks with fewer joints are left behind, and the largest blocks are left standing. These landforms are Dartmoor famous toros like bower and nose
How does the landscape near malham in the Yorkshire dales shows how the Carboniferous limestone rocks and physical processes interact to create cliffs, deep gorges, impressive valleys, beautiful waterfalls and unusual limestone pavements?
One distinctive landform is Malham cove, a high limestone cliff shaped like an amphitheatre. Over millions of years, earth movements caused the large middle craven fault to form with the softer rocks slipping, creating a line of limestone cliffs. About 15000 years ago at the end of the last ice age, melting water from glaciers created a massive waterfall which eroded the cliff back to its current position. The combination of water flowing over the cove, as well as its erosion, weathering and mass movement processes, created it. Along the top of malham cove the structure of Carboniferous limestone has created limestone pavements. The rock is made of blocks with horizontal lines (planes) and vertical cracks (joints). As rainwater passes through the lines of weaknesses in the rock, it causes a chemical reaction which enlarges the joints and bedded planes. The widening and deepening of the cracks on the surface form grykes, exposing blocks of limestone called clings and creating pavement
Describe the north and South Downs
75 million years ago during the Cretaceous period brains in was covered in tropical sea which resulted in marine deposits that created chalk foundations of the north and South Downs. 30 million years ago, large earth movements caused the compacted layers of sediment to be forced upwards, creating a giant, chalk-covered dome. Over many year water eroded this chalk, revealing the older sandstone beneath which form the high and low Weald. The north and South Downs formed from the remaining chalk at the edges of the dome. The dome experienced erosion, removed the softer rocks at the centre of the dome and left the two escarpments of the north and South Downs. The South Downs consists of the steep scarp slope and dip slope where the slope is gentler. At the top of the escarpment there are gently rolling hills. During the last ice age the processes of weathering and erosion created the v-shaped dry valleys, distinct hilltops and ridges that from the landscape today
Describe agriculture on the South Downs national park
85% of the national park in farmed, with 1100 farm businesses operating. Chalk grassland is ideal for grazing sheep and training race horses because the grass is short and rich in nutrients. Clay grasslands is better for dairy cows cos of the longer grass. On the south facing lower slopes of the south down, the deeper soils are more suitable for arable farming like wheat, barley and vine cultivation
What are the advantages of farming in the South Downs?
The income supports the local economy, 6% of employment on the park is for agricultural businesses
Arable farming has contributed towards supports rare bird species on the South Downs, which include the corn bunting, grey partridge etc
The formation of hedgerows and field margins has led to wildlife corridors for bats
What's the disadvantages of agriculture of the South Downs
The decline in arable farming changes in farming practices have reduced the presence of arable plants, which had damaged wildlife habitats
There has been a significant decline in chalk grassland from the use of chemicals in farming
The decline of traditional practices such as extensive sheep grazing has led to scrub encroachment on the remaining chalk grassland
Describe forestry in the South Downs
The South Downs has a widespread mix of deciduous and coniferous woodland covering a total of 23.8 of the park and is a key feature of the western half of the national park. The distribution of woodland across the national park is uneven, with the west being significant,y more wooded than the east. Human activity areas of the UK has increased, resulting in large areas being cleared
What are the advantages of forestry on the South Downs national park
A large percentage of the woodland that makes up the South Downs is made up of ancient trees, which provide habitats for a diverse range of wildlife
The timber harvested from the woodland is a valuable sustainable product, with growing markets in construction and fuel for heating
What are the disadvantages of forestry on the South Downs national park?
The removal of woodland for new developments is threatening some if the ancient large leaved lime woodland
Many of the hazel and chestnut copies are under threat, because people no longer manage them in the traditional way. As they became overgrown, so the quality of the woodland and biodiversity declines