geography Flashcards
Limestone landscapes in the Uk?
Yorkshire dales, North Yorkshire moors, Peak District, Brecon Beacons
What is carboniferous limestone?
Is a sedimentary rock. Limestone is calcium carbonate and is formed in warm shallow tropical seas from organic matter.
Water can pass through ( its joints and cracks) limestone? What is the name for it.
Permeable rock.
What are bedding planes?
layers of material built up on the sea bed, forming horizontal layers called bedding planes.
What are joints?
Vertical cracks called joints were created when the rock dried out and also when there was tectonic plate movement.
what are the two ways that limestone can get eroded?
- chemical weathering & 2. Solution
Explain the the ways?
- rainwater- mixes-carbon dioxide- makes a weak acid m- carbonic acid. It chemically weathers the rock and dissolves it very slowly.
- turns into a solution - carried away by running water - action- responsible for distinctive features in the uplands.
Name the limestone surface features?
Limestone pavement, swallow holes/pot holes, Scars
Explain the formation of limestone pavement?
Glacial abrasion scraped away the topsoil exposes the bare rock. As limestone is permeable the rain water (carbonic acid) seeping in enlarging the joints and bedding planes .Dues to chemical weathering joints widens to create grykes and bedding planes leaving exposed called clints - pattern is called limestone pavement. Eg. Malham cove
Explain the formation of Scars?
- Scar are exposed cliffs of limestone
- They were formed during ice age , when huge sheets of ice scraped away the soil covering.
- the exposed surface is then affected by freezing and expanding and cracking.
- Repetition of the action breaks rocks and at the bottom forms scree slopes. Eg . Twistleton Scars
Explain the formation of Swallow holes/pot holes?
Are a natural depression on the surface of a limestone landscape erdoed by chemical weathering. An enlarged gryke.
Name the Limestone underground features?
Caverns, Stalactites/stalagmites, Gorge, Intermittent Drainage.
Caverns?
large caverns formes in carbonifrous limestone landscaped. They Form when chemical solution is more active.
Small caves develop where joints and bedding planes are close.
Large caverns develop when cave roofs collapse.
Caverns can also eroded by the usual river erosion process- hydraulic action- corrosion
Eg. Battlefield cavern
Stalactitus/Staglagmites & pillars
- the calcite build up to form a stalatites hanging from the roof, as drip land on the floor again carbon dioxide leaves and calcite deposits form a stalagmite.
- Occasionlly when stalatites and Stalagmite meet to form a pillar.
- Evaportation through process known as gas diffusion..
Gorge
A steep sided valley
formed during the proces of dissolving limestone- cavern fomation continues over and over - get larger and larger
Everntually les to support the roof will collapse.