Key Terms for a 1

							Key Terms:


  1. Anothosite- a granular plutonic rock composed largely of labradorite or a more

     calcic feldspar

  2. Continental drift- the lateral movement of continents resulting from the motion of

     crustal plates

  3. Convection- the transfer of heat by the circulation or movement of the heated

     parts of a liquid or gas.

  4. Core- the central portion of the earth, having a radius of about 2100 mi. (3379

     km) and believed to be composed mainly of iron and nickel in a molten state.

  5. Coronal mass ejection- a large-scale solar event involving an ejection of hot

     plasma that may accelerate charged particles and travel as far as the Earth's

     orbit, preceded by a shock front that may create a magnetic storm on Earth.

  6. Crust- the outer layer of the earth, about 22 mi. (35 km) deep under the

     continents and 6 mi. (10 km) deep under the oceans.

  7. Dynamo theory- proposes a mechanism by which a celestial body such as the

     earth generates a magnetic field.

  8. Ejecta blanket- generally symmetrical apron of ejecta that surrounds a crater; it is

     layered thickly at the crater’s rim and thin to discontinuous at the blanket’s outer

     edge.

  9. Fission theory- the splitting of a heavy element into lighter elements.

  10. Highlands- a mountainous region