Weathering breaks rocks into fragments, that are transported to the ocean by rivers. Fragments fall to the bottom as sediments.
- The sediments are squashed (compaction) and cemented together by minerals.
Fossils form in sedimentary rock when:
- Organisms fall into the sediment.
- Not enough oxygen to cause the organism to decay.
- Organisms has solid enough parts to leave a caste in the rock.
- Water filtering through desposits minerals in the caste.
Rocks may be eroded by wind and water, producing small fragments.
- In time, the layers are uplifted and exposed to wind and water.
- The different layers erode and different rates due to varying properties.
The chemical in limestone, chalk and marble is calcium - CaCO3.
- Limestone is quarried for use in making glass, cement and concrete.
Makes glass by heating limestone, sodium carbonate and sand together.
Cement by heating limestone and clay.
Concrete by mixing sand, gravel, cement and water.
Problems of quarrying is the creation of noise and dust, damage to animal habitats and traffic congestion/road damage.
Advantages of quarrying limestone is it provides jobs and the limestone industry is important for the local and national economy.
Negative impacts of quarrying is minimised by restricting quarry size, blasting in quarries at specific times, using water sprays to reduce dust, earth barricades to reduce noise and rebuilding the land when it closes.