the earth

• the crust is rocky and between 8-40km thick
• mantle is made up of solid rock but can flow
• Outer core is a liquid and made of iron and nickle
• Inner core is the solid centre of the earth
• Igneous rocks are made from crystals with no gaps inbetween
• Convection currents move hot molten material from the inner core to the surface
• Sedimentary rocks are formed by layers of sediments that have been compressed together over time
• Metamorphic rocks are formed when existing rocks change due to heat or pressure
• Igneous rocks are not porous as they don’t allow water in
• Igneous rocks are formed from molten rock that has been cooled and solidified
• sedimentary rocks are made up from little grains of other rocks quashed together that build up over time
• Sedimentary rocks are porous
• The stages of forming sedimentary rocks are

  1. Erosion
  2. Deposition
  3. Compaction
  4. Cementation
• 3 types of weathering are biological chemical and physical
• biological weathering is the breaking up of rocks by plants and animals
• chemical weathering is the breaking up of rocks from the action of chemical and rain
• physical weather is the breaking up of rocks from water freezing and expanding