Study Guide for Geologic Time Test

Know the difference between relative & absolute dating

Know Steno's 3 prinicples & how you can use them to date rocks and fossils

Principle of superposition; Principle of original horizontality; Principle of cross cutting

Be able to put rock layers in age order (oldest to youngest or youngest to oldest) using these principles

Fossils

Understand what index fossils are (faunal succession - William Smith)

Be able to put rock layers in age order using index fossils

Know the different types of fossils & be able to identify them - mold; cast; replaced remains; original remains; trace

Know what Illinois state fossil is; Know what the La Brea Tar pits are in Los Angles; Know who Sue is (Chicago's Field Museum)

Absolute Dating

Radioactivity - understand what beta & alpha radioactivity is and what happens to the parent atom

Understand what half life is (parent & daughter atoms) and how we use it to date rocks

Be able to graph the amount of radioactive atoms in a rock sample over a period of time and use the graph to find that atom's half life