You must know and be able to describe and explain:Physical weathering

Freeze-thawExfoliation

Chemical weatheringLimestone solution

IgneousSedimentaryMetamorphic

Formed by fire – magma in the interior of the Earth

Formed by the cooling of lava or magma

Examples – Basalt and Granite

Made up of small particles transported by water, ice and wind

As more sediment accumulates the weight causes the rock to form

Weak rock generallyExamples –

Sandstone, clay, limestone and chalk

Originally igneous or sedimentary rock which have been altered by heat and/or pressure

ExampleLimestone into

MarbleClay into Slate

All the Granite rocks in the UK are found to the north and west of the Tees-Exe line

The rock which forms tors is that which remains after the surrounding rocks have been weathered and carried away.

Where tors occur, the joints in the granite are wider apart than in the rock around them

Freeze-thaw weathering can operate more effectively and blocks of rock break off more quickly where the joints are close together, because there are more cracks in the rock for the water to fill

Each time the water freezes and expands within a joint, more pressure is put on the surrounding rock and the crack widens.

Where there are fewer joints, it takes longer for the blocks of rock to be broken off and the block are left upstanding as Tors

ReservoirsPoor grazing land for Cattle and SheepDartmoor – PoniesBuilding materials and gravestones

In the Uplands of England and WalesThe Yorkshire Dales – Malham and IngletonPeak District near CastletonThese rocks are very susceptible to chemical

weathering

Limestone pavements – flat surfaces of bare rock broken up into separate block

The flat surfaces of the blocks are clints and the gaps are grykes

Rivers disappear underground either through small holes in the rocks called sink holes or down larger holes with a funnel shape above called swallow holes

Underground limestone is full of holesForms large chambers, caves and cavernsStalactites made of lime hang down from the

roofs like long iciclesStalagmites are the thicker columns built up

from the floor

Good for sheep farming – grazing the short turf-like grass which grows

Limestone landforms are attractive to visitors – tourist attractions – Gift shops in Castleton etc

Farmers can ear extra income from campsites and bed and breakfasts

Used as a building material – St. Paul’s CathedralWhen crushed it can be used for fertiliserUsed a cleanser in many industries – power

stationsQuarrying

Chalk is a soft, white, porous form of limestone composed of the mineral calcite. It is relatively resistant to erosion so forms tall steep cliffs where chalk ridges meet the sea e.g. Beachy Head along the south coast of England

Chalk is porous which means that water can pass through and be stored in the pore spaces between the particles of rock. When it rains, water infiltrates into the chalk layers and saturates the chalk. The upper level of saturation is called the water table.

Many water companies drill boreholes into the chalk rock to supply water to nearby settlements.

Chalk forms distinctive landscapes with steep escarpments and gentle dip slopes. The hills may have dry valleys which show the characteristics of a river valley but have no water flowing along them. The North and South Downs in south-east England (UK) show all these features

There are two requirements before an escarpment can be formed:Alternate outcrops of different types of rocks.

One rock needs to be soft and the other needs to be more resistant to erosion

Beds of rock dip at an angle to the ground surface. Instead of being horizontal, the beds were tilted by earth movements so that they lie at an angle to the surface

The clay is eroded more quickly than the chalk

As the clay is eroded down into the vale, the chalk is left standing up because of its greater resistance

The scarp slope forms a prominent feature where the layer of chalk reaches the surface

The dip slope is more gentle following the tilt of the beds of rock

Settlement - see Fulking case studiesGood for pasture and training racehorsesGood building materialUnderground water supply – called aquifers