Chapter 6 Weathering Flashcards
What is denudation
Wearing down of the surface of the earth
Two types of weathering
Mechanical
Chemical
Erosion
Wearing away of rock,the transportation of the Rock and its deposition.
Carried out by rivers, the sea glaciers and wind
Weathering
The breakdown of rock. Usually by the forces of weather. The broken rock lies where it has been broken.
Two types of mechanical weathering
Freeze thaw action
Exfoliation
Carbonation
Rain falls and takes in carbon dioxide from the air.
Carbon dioxide worked like a week acid.
Opens cracks and joints in limestone.
Called carbonation
Stalagmite
Stalactite
Stalagmite from ground
Stalactite from ceiling
Karst landscape
In the ice age glaciers cleared away the earths covering. Eg the burren.
Features of a karst landscape
Swallow holes
Underground rivers+caves
Limestone pavements
Clints
Blocks of limestone form pavement
Grikes
Gaps between the blocks. Joints in the rocks were opened wider during process of carbonation.
Swallow holes
Openings in the surface through which the rivers disappear underground.
Open cast mining
Is used when rocks and minerals are close to the surface. Quarrying
Shaft mining
Used to extract rocks and minerals deeper I the ground
Igneous rock
Formed when magma or lava cooled beneath and above the surface
Eg granite, basalt
Sedimentary rock
Formed when existing rocks, animal and plant life were worn down and compressed to form new rocks
Eg limestone, sandstone
Metamorphic rock
When existing rocks are changed by great heat and/or pressure
Eg marble, quartzite, slate
Marble
Limestone changed by great heat and pressure
Different colours black from coal Kilkenny Red from sandstone cork Uses.
Kitchen work tops,sculptures, Eg
headstones Connemara marble Co.Galway
Limestone
Formed from shells and bones of fish at the bottom of the sea. Pressure from these layers formed it. Most common rock in Ireland. 40% is it.
Uses. Eg
Building road surfaces ,buildings The burren Co.Clare
Cement.
