Puzzling Earth

2. the rigid outer part of the earth, consisting of the crust and upper mantle.
4. the product which remains after an original isotope has undergone radioactive decay.
7. emitted during the decay of naturally-occurring radionuclides in the earth
9. A technique used to determine the age of materials, such as rocks or fossils.
10. an elastic wave in the earth produced by an earthquake or other means.
11. A rock or other matter from space that has landed on Earth
13. The third layer of Earth´s atmosphere.
14. A process that involves the movement of energy from one plce to another and is causeed by differences in temperature and density within a liquid or gas.
15. the upper layer of the earth's mantle, below the lithosphere.
16. The process by which an unstable atomic nucleus loses energy by radiation.
18. The first form of an isotope during radioactive decay
20. massive, irregularly shaped slabs of solid rock in the Earth.

1. an area on Earth where two or more lithospheric plates collide
3. is thickened by the compressive forces related to subduction or continental collision.
5. A type of plate boundary where 2 tectonic plates slide past each other horizontally
6. Produces the magnetic field around the earth
8. Makes up the seafloor of the Earth
12. the innermost layer of the Earth.
17. a layer within the Earth between the crust and the core.
19. a linear feature that exists between two tectonic plates that are moving away from each other