ARCH 100 Lecture Notes - Lecture 5: Accelerator Mass Spectrometry, Sinodonty And Sundadonty, Blackwater Draw
11 Feb 2018
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Chopping tool: oldest humanly made object in the british museum. Used for many purposes chopping bones, plants & wood: making, using & sharing things played a key role in developing human behavior. The ability to make tools allowed humans to adapt to new environments & out-compete other animals. Changed now: siberia: glacier-free, grassland, herbivores, hunter-gatherer cultures, radiocarbon: carbon-14 dating. Plants take it up and animals eat plants. When plants & animals die, carbon-14 begin to decay at a steady rate (half life). Use this rate to determine when organic objects died: calibration: half-life works, but varying levels of c-14 in atmosphere not constant. Calibration curve created using dates of known organic objects. (cal bp, cal bc/ad, etc: rcbp: radiocarbon before present, ams (accelerator mass spectrometry): more accurate than traditional radiocarbon dating. Measures # of c-14 atoms in the object to be dated. Geiger counter to count beta particles being emitted by c-14 atoms as they decay.
