ANP 203 Lecture Notes - Lecture 13: Optically Stimulated Luminescence, Thermoluminescence Dating, Tooth Enamel
Document Summary
The 14 c level in the atmosphere is affected by: Carbon uptake/release in organic matter, the ocean, ocean sediments/methane hydrate) and sediment rocks which fluctuates w/ glacial and interglacial episodes. Burning of fossil fuels - not radioactive carbon in air. 14 c concentrations are well mixed in atmosphere, 40 year correction in s. K-ar dating, ar-ar dating dates volcanic rocks, ash deposits. Trapped charge dating - background gamma radiation from the decay of uranium, thorium, potassium in sediments causes electrons to be trapped in crystal lattices in quartz sands and feldspars. How: experimentally determine the background radiation that accumulates annually using dosimeter, expose the sediment sample to light or heat, which frees the trapped electrons. These electrons generate light, which is measured and yields the estimate of the amount of trapped electrons. Thermoluminescence dating - used on kiln-fired ceramics, hearth sediments, burned artifacts. Dartes the last time an object reached 500 o c.
