Structure of the Earth

• Definition of an Asteroid 


  A rocky object orbitting the sun that is thought to be left over from the formation of the solar system
• Definition of a Meteorite?


  A piece of rock that has fallen to the earths surface from outer space
• Where do most meteroites come from?

  The asteroid belt
• Name the 3 types of meteorite

  Iron, Stony and Carbonaceous chondrite
• What are the characteristics an Iron Meteorite? 


  its made of nickle and iron, is 6% of known meteories
• Interpretation of an Iron Meteorite


  Represents the core of a planet like object
• Characteristics of a Stony Meteorite


  made from silicate minerals, is 93% of known meteorites
• Interpretation of a Stony Meteorite


  represents the mantle of a planet like object
• Characteristics of a Carbonaceous Chondrite


  special type of stony meteorites, has water and organic compounds
• Why are Meteorites useful?


  We assume that all meteorites come from the same source, therefore when they land on Earth they show us information about the chemical composition of this source
• Meteorites that have landed on earth are not the same as crustal rock because the crust has been changed by processes like weathering
• What are the 4 Goldschmidt Groups?


  Siderophile, lithophile, chalcophile, atmophile
• Atomophile


  ‘Gas Loving’ occur as liquid or gasses, E.G. Nitrogen, Neon, Hydrogen
• Lithophile


  ’Rock Loving’ combine with oxygen, E.g. Sodium, Potassium, Lithium
• Chalcophile


  ‘Ore Loving’ combine with sulphur, E.g. Silver, Copper, Zinc
• Siderophile


  ‘Iron loving’ combine with iron, E.g. Iron, Nickle, Gold
• From Low Density to High Density

  Atomophile - Lithophile - Chalcophile - Siderophile
• Layer of the Earth

  Atomophile - Atmosphere/Ocean

  Lithophile - Crust

  chalcophile - mantle

  Siderophile - Core
• Proto-Earth was a collection of all possible elements.

  Then due to gravity the denser compounds moved towards the centre and accumulated at the core, pushing the lighter compounds outward to create the mantle
• Chemical Propertied:

  1. Crust - Solid
  2. Mantle - Solid
  3. Outer Core - Liquid
  4. Inner Core - Solid
• Mechanical Properties

  1. Lithosphere - Rigid and Brittle
  2. Asthenosphere - Ductile, Partially Melted
  3. Mantle
  4. Outer Core
  5. Inner Core