Processes of Denudation chapter 5 Geography

Biological weathering is the breakdown of rock caused by plants and animal.

Mechanical weathering, often referred to as physical weathering, is the breakdown of rock into smaller pleces by natural forces .

Freeze-thaw action is a form of mechanical weathering that occurs in areas where the temperature regularly rises above and falls below freeze ( 0*C ).

2. At night temperature drops and causes the water to freeze.

3. As the water turns to ice, it expands by 9 per cent of it's volume. This expanding widens the orginal crack in the rock, creating a larger crack.

4. Once the temperature rises again, the ice melts to water and the widened crack collection more water.

The weathered rock collection at the base of a hill and is called screen.

1. Rainwater is carried in streams across the land scape of the Burren .

2. These streams carve out a path and flow down through swallow .

2. This leads to the creation of a cave, which is a large underground area that is formed over time by carbonation.

4. As the temperature rises underground, the water present beings to evaporate.

5. The process of evaporation leaves behind a tiny amount of the mineral calcite. Calcite builds up over time to form a stalagmite, which is a build-up rock on the floor of a cave.

6. Some of the evaporated water sticks to the roof the cave and can drip back to the ground. Calcite is also left behind on the roof of the cave to form a stalactite, which is an inverted stalagmite that forms on the roof of a cave.

7. Stalagmites and Stalacitites can often grow towards each other and eventually connect to form a pillar.

8. The stream that once entered through the swallow hole creates a new pathway out of the cave and it continues to flow underground.

9. Futher down the landscape the stream may emerge on the surface again.

the surface of the Burren tells the story carbonation over time.

The landscape that has evolved here is called limestone pavement, which is large slabs of limestone rock that are separated vertically by joints and horizontally by bedding planes.

Carbonation dissolves and weathers the joints and bending planes present in limestone pavement .This widens the joint and creates many surface features as it weakens and breaks down rock:

A grike is a deep gap or groove between slabs of limestone.

A clint is a slab of limestone separated by grikes.

A Karren is a circular-shaped scoop that forms on the surface of a clint.

A swallow hole is a hole in the landscape were the rock has been dissolved. A swallow hole allows a river or stream to flow underground.

1. Carbon dioxide (CO2) gas is naturally present in the atmosphere. Factories, cars and homes also relese carbon dioxide into the air.

2. This carbon dioxide gather and is transported in clouds.

3. When rains falls from clouds it absorbs more carbon dioxide from the atmosphere . this additional carbon dioxide turns the rainwater into a weak carbonic acid.

4. The acidic rainwater falls on the limestone landscape of the Burren and enters rivers and streams . Reacts with the calcium carbonate in limestone and forms calcium bicarbonate, which dissolves limestone rock over time. This dissolves rocks is washed away by flowing water.

5. Limestone is a permeable. makes down continues to dissolve the limestone that is underground.

Denudation is the breaking down and carrying away of material over time caused by the processes of weathering and erosion .

Weathering is the breaking down or dissolving of minarals and rocks across the surface of the Earth.

The broken-down material may or may not be transported.

Erosion is the wearing down and transportation of materials across the surface of the earth.

Weathering is grouped into three main categories: mechanical, chemical and biological .

Chemical weathering is the breaking down or dissolving of minerals in rocks caused by a chemical reaction .

Carbonation is an example of chemical weathering that involves carbon dioxide and calcium carbonate.

A Karst region is a large area defined by limestone rock .