Shaping The Earths Crust Flashcards
What is weathering?
Weathering is the breakdown and decay of rocks that are exposed to weather. It takes place in one place and the material is not moved
How does denudation occur
Occurs by weathering and erosion
What is erosion
Erosion is the breaking down of rocks and the removal of the particles. These particles are moved or deposited else where eventually.
What is erosion caused by
Moving air, water, and ice
Wind
Glaciers
Rivers/lakes
Name the two types of weathering
Chemical weathering and mechanical weathering
What is mechanical weathering and what does it cause
It causes the rock to break up into smaller pieces.
Ex:Freeze-Thaw
How does freeze thaw work
Up on a mountain it’s colder the higher up you go. When you get to below zero degrees, water freezes.
When at this temperature, it rains and the rain can rest in tiny cracks in the rock on the mountain. When it freezes it expands and puts pressure on the rock. This repeats over and over untill the piece of rock breaks off because of the pressure and makes smaller pieces of rock called scree. These coolest at the bottom of a slope or just rest beneath where they fell from.
What is chemical weathering
Chemical weathering happens when rocks decay or dissolve because of a chemical change.
Ex:carbonation
Explain carbonation
Carbonation is when rain collects carbon dioxide as it falls through the atmosphere, which mixes with the rain to form a weak carbonic acid. Limestone contains calcium carbonate. When rain hits the rock it reacts with the calcium carbonate and slowly dissolves it.
What is a karst landscape
It’s the land after carbonation has occurred.
Ex: the burren
What is a clint
The left over stone after carbonation. The blocks of stone left unharmed
What is a grike
Cracks in the rock caused by carbonation
Where would you find a stalagmite
On the ground
Where would you find a stalactite
On the ceiling
Name two differences between weathering and erosion
Weathering is the breakdown and decay of rocks and erosion is the decay and the removal of the particles as a result. There are two types of weathering and three causes of erosion.
What is scree
Scree is the particles of rock left behind as a result of the freeze thaw action
Explain freeze-thaw
As you go up a mountain the temperature drops. When it’s below 0*C water freezes.
When rain falls it collects in the cracks of the Rock on the mountain.
When night falls the water freezes and expands.
This happens over and over until the rock breaks because of the pressure. The rock breaks into smaller rocks called scree which will collect at the bottom of the slope.
Why does freeze thaw happen upland mostly.
As it’s colder up there and wouldn’t be cold enough for water to freeze
Explain why water can get through limestone
The rock is permeable and it also has small vertical cracks called joints and horizontal bedding planes. These help easing the water through.
What is a bedding plane
The line in rocks that seperates two layers of strata.
What is a swallow hole.
When rivers flow onto a limestone surface they dissolve it by carbonation, and this widens the joints and bedding planes, opening them up. Soon the river starts to flow underground, and disappears from the surface. The passage which through the water enters to get underground is called a swallow hole.
What is a cave
When the river flows underground the water cuts out long tunnels by carbonation. These are called caves
What is a cavern
Sometimes a cave is enlarged and forms a large chamber called a cavern.
What’s a pillar
This is formed when stalagmites and stalactites join together
How are stalactites formed
When water containing calcium carbonate seeps through the cave or cavern some droplets may hang from the ceiling for a while. Some of the water evaporates leaving calcite attached to the roof. These then build up over thousands of years.
How are stalagmites formed
When droplets of water containing calcium carbonate collect on the floor the water evaporates and leaves calcite. These build up over thousands of years.
Nam the four main attractions of the burren
Fauna, flora, history, landscape
What is flora
Flora is the plant life at the burren
What is fauna
The animal life at the burren,
Ex: the green moth, butterflies, pine martins, wild goats
Why is the landscape an attraction at the burren
The burren has a varied landscape. It has a wide range of scenery for tourists. These include the karst landscape, the Aillwee Caves, and the cliffs of moher. Caver’s and ad rock climbers are also very attracted to the burren.
Tell me about the history of the burren.
The burren has many historical monuments and archaeological sites that show evidence a long history of settlements. They include dolmens, ring forts and carved crosses and churches.
List the benfits of increased tourism to the burren.
Increases a rise in local employment.
This in turn reduces out migrations
There are spin off benefits for shops, coach owners and craftspeople.
improved facilities such as roads
List some disadvantages to increased tourism in the burren
Increases the risk of damaging flora
Noise and pollution changes the nature of the burren
Increases the risk of damaging historical monuments
New roads= more traffic = more pollution
