EARTH SCIENCE (CETS)

• Law of Superposition


  oldest layers of rock is at bottom and youngest is at top
• Radioactive Dating


  some materials change to another material which can be helpful in identifying its age
• Uranium-Lead Method


  Uranoum 238 changes into lead
• Fossils


  hardened imprints/remains of organisms
• Paleontologists


  studies fossils
• Cast Fossil


  sediment seep through dead organism, organism breaks, then sediments harden
• Ice & Amber


  can stop/prevent decay of organism
• Geologic Time Eras


  Precambrian Era, Paleozoic Era, Mesozoic Era, Cenozoic Era
• Paleozoic Era Periods


  1 Cambrian Period

  2 Ordovician Period

  3 Silurian Period

  4 Devonian Period

  5 Mississippian Period

  6 Pennsylvanian Period

  7 Permian Period
• Cambrian Period


  Rodinia breaks apart resulting in Gondwana (largest), Laurentia (2nd largest), Siberia, & Baltica; 1st vertebrate and invertebrate fossil records; more life on water