ANT 304 Lecture Notes - Lecture 9: Archaeomagnetic Dating, Tooth Enamel, Nuclear Weapon
Document Summary
Use same species of trees to date. Use as dating method and calibrate radiocarbon dating. Don"t use in tropics because of biodiversity in flora. Rely on radioactive decay of isotopes - decay is constant. Decay starts with death and/or deposition in a sealed context. Parent - unstable isotope that decays over time. Daughter isotope - the decay product, or remaining element after radioactive decay. Half-life - decay rate is constant, time to decay to daughter. Dates organic material only - charcoal, burnt seed/food. C14 is unstable isotope - remain stable in atmosphere. Stops when you are dead - fix carbon when you are alive. 1949 - willard libby discovers carbon dating - made assumptions. Environmental factors don"t influence initial c14 in organic matter. Nuclear bomb has had large impact on carbon dating. Need to calibrate dates - with dendrochronology. Dates mineral and some crystalline rocks - obsidian. Artifacts exposed to heat/light and electrons become trapped.
