Erosion and weathering
Scree: lime stone tends to erode along the joints due to freeze thaw, this causes the parts to break off and fall to the bottom of the rock face to join the rest of the scree.
Terraces: Limestone terraces are exposed bedding planes. Terraces are formed when limestone is eroded along joints and bedding planes on the scarp slope. Blocks of limestone are removed leaving the terracing.
Limestone pavements: Where limestone outcrops at the top a hill, limestone pavements will form. The surface of the pavement is an exposed bedding plane and the exposed joints become widened, to form grykes, the blocks of limestone that remain between the grykes are called clints. Acidic rainwater will collect in the clint which will widen and deepen it.
Caves/swallow holes: these are formed by melt water eroding a weakness in the limestone
Uses of limestone
- Lime stone can be heated with clay to make cement, it can then be mixed sand, water and crushed rock to make cconcrete.
- Limestone can be heated which makes quicklime, if you the add water you will make slaked lime which can be used to neutralise excess acidity in lakes and soils.
- It can be used as a building material and in the manufacture of iron.
- It can be hated with sand and soda to make glass.
Limestone features
Limestone and recreation
Limestone areas provide many uses for people such as potholing, caving, climbing, walking and many other outdoor activities.
Case study: Malham Cove
Malham cove is a very large natural cliff, standing some 80m high and 300m wide which is positioned just north of the mid craven fault. Malham cove is a curved crag of carboniferous limestone which was formed after the last ice age. Melt water produced a waterfall that cut back the cliff, the erosion took place mainly at the lip of the fall which is why there’s a curve in the cliff. After the last ice age the waterfall stopped because the water seeped down into the cracks and fissures, and therefore the water level never rises enough to produce a waterfall again.
The cove has distinct vertical ledges, which are a result from variations in the hardness of the limestone layers. Dark vertical stripes are created on the cliff by lichens and mosses as water seeps down the face of the rock.
The surface of the cove has a limestone pavement which has deep fissures as a result of chemical weathering, which is mainly acidic rain. The rain seeps down into the cracks and attacks the limestone causing the formation of Clints and grykes.