GCSE: OCR gateway: C2: Structure of the earth + construction materials
- Created by: 09tvzutphen
- Created on: 07-04-14 14:15
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- C2
- The Structure of the Earth
- The Lithosphere
- The crust and the top part of the mantle
- Cold and rigid
- Made up of tectonic plates which are less dense than the mantle below
- Crust too thick to drill through so most imformation about the earth is obtained by seismic waves created by earthquakes and man made explosions
- The Earth's Structure
- Mantle cold and rigid below the crust however at greater depths is is non-rigid and able to move
- The earth's core transfers energy so the temperature of the mantle increases with depth
- Convection currents slowly move plates
- Subduction
- Oceanic crust is denser than continental crust
- When plates collid the oceanic crust is forced down
- Cooler at the margins than continental crust
- Partly melts as it reaches the hotter part of the mantle
- When plates collid the oceanic crust is forced down
- Oceanic crust is denser than continental crust
- Plate Tectonic Theory
- Scientists accept theory because it explains a wide range of evidence + has been discussed and tested by many scientists
- Wegener's theory not accepted at the time
- Magma and Rocks
- Magma rises through the crust as it is less dense forming volcanoes
- Different types of magma composition make different kinds of eruptions
- Geologists study volcanos to predict future eruptions + find out more about the earth's structure
- Magma rises through the crust as it is less dense forming volcanoes
- The Lithosphere
- Construction Materials
- Raw Materials
- Some raw materials are found in the earth's crust
- Hardness can be compaired by rubbing two materials together
- Rock Hardness
- Sedimentary rock
- Soft sediments compressed together so its soft
- Metamorphic rock
- Formed when sedimentary rock is changed by heat and pressure
- Compressed into a mosaic of interlocking carbonate crystals
- Makes it harder as it has been baked
- Compressed into a mosaic of interlocking carbonate crystals
- Formed when sedimentary rock is changed by heat and pressure
- Igneous rock
- Formed when magma cools and solidifies
- Granite has interlocking crystals so it is very hard
- Sedimentary rock
- Cement and Concrete
- Thermal decomposition
- When a substance breaks down from heating to give two new substances
- Calcium carbonate = calcium oxide + carbon dioxide
- CaCO3 = CaC + CO2
- Limestone heated with clay makes cement
- Mixing cement, sand, and small stones with water makes concrete
- Composite materials
- Thermal decomposition
- Reinforced Concrete
- Under compression concrete is strong however under tension it is weak
- If heavy loads are applied to a concrete beam the concrete will bend creating tension and compression
- This cracks the concrete
- If heavy loads are applied to a concrete beam the concrete will bend creating tension and compression
- Reinforced concrete is harder and more flexible than concrete so it is a better construction material
- Under compression concrete is strong however under tension it is weak
- Raw Materials
- The Structure of the Earth
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