Geography: weathering
What is the Burren landscape called?
A Karst Landscape
What is the limestone pavement?
A limestone pavement is the bare surface of the limestone divided into blocks.
Where does the Karst Landscape get its name?
An area of exposed limestone in Slovenia
When the water evaporates what does it leave behind?
Calcite
What is an example of this?
Carbonation
What are stalactites?
Cone shaped deposits of minerals that hang down from the ceiling of a limestone cave.
What are stalagmites?
Cone-shaped deposits of minerals that are built up from the floor of a limestone cave.
How does a Karst Landscape form?
During the last Ice Age, the glaciers cleared away the earths covering exposing the bare rock of the Burren.
What is erosion carried out by?
Erosion is carried out by rivers, the sea and glaciers.
What is an example of mechanical weathering in hot climates?
Exfoliation
What is an example of mechanical weathering in glaciated regions or higher altitudes?
Freeze-thaw action
What is Carbonation?
Limestone is dissolved by carbon dioxide in rainwater. When rain falls it takes in carbon dioxide from the air. The carbon dioxide acts like a weak acid(carbonic acid) to open cracks and joints in the limestone by dissolving the limestone.
What are the features of a Karst Landscape?
Limestone pavements,swallow holes,underground rivers and caves.
What is mechanical weathering?
Mechanical weathering occurs when rocks are broken apart by physical force applied by frost and plants for example.
What are Swallow Holes(aka Sinkholes)
Openings in the surface of the limestone through which the rivers disappear underground. They are created by Carbonation.
What are the broken rock pieces called
Scree
Where is there an example of all three?
The Ailwee Caves, Co. Clare
Where can the effects of carbonation be seen?
The Burren, Co. Clare
Where is there an example of scree?
The Great Sugar Loaf, Co. Wicklow
What are Clints?
The blocks of limestone that form the limestone pavement p.
Weathering
The breakdown of rock usually,by the forces of weather. The broken rock lies where it has been broken. There are two types of weathering, mechanical and chemical
What are Grikes?
The gaps between the blocks.joints on the rock were opened wider when the limestone was dissolved by rainwater through the process of carbonation.
Why is exfoliation called onion weathering?
The outer layer of rock peels or cracks away from the inner layers of rock?
What happens during the day?
The rock contracts when the ice melts. This continues and it puts pressure on the rock which eventually breaks off.
Underground Features
The underground rivers open up caves and caverns in the limestone.
Erosion
The wearing away of rock, the transportation of that rock and its deposition.
Denudation
The wearing down of the surface of the earth. It is done by weathering and erosion
How does freeze-thaw action work?
Water enters cracks in the rock. During the night the water is frozen and it expand the cracks.
When does chemical weathering occur
When a chemical change in the rock causes them to dissolve
When are pillars/columns formed?
When stalactites and stalagmites join together.
When is this caused?
When the outer layer of rock is heated during the day and it expands. The rock then contracts during the cold nights.
How are stalactites formed?
When water drops containing dissolved limestone(calcite) form on the roof of a cave.
Where does freeze-thaw action happen
Where the temperature rises and falls above zero degrees and where there is precipitation