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The Age of Things: Sticks, Stones and the Universe. Correcting and Using Carbon 14. http://cfcp.uchicago.edu/~mmhedman/compton1.html. Last Time:. Current Carbon-14 Fraction Original Carbon-14 Fraction. R =. Carbon 14 All Carbon. Carbon-14 Fraction =. R. A personal aside:. R.
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The Age of Things:Sticks, Stones and the Universe Correcting and Using Carbon 14 http://cfcp.uchicago.edu/~mmhedman/compton1.html
Last Time: Current Carbon-14 Fraction Original Carbon-14 Fraction R = Carbon 14 All Carbon Carbon-14 Fraction = R
My Answer: This says the tree from which this sample was taken was fallen ~14000 yrs ago. However, (we) cannot judge this date as valid w/o adequate context: Does this date make sense in terms of other dates at the site? For a single date is not very reliable in these situations. Furthermore, is the sample contaminated? Could there be factors that would cause the date to be erroneous? Also the date has not been properly altered to take into account fluctuations in radiocarbon levels from year to year. Finally, even if the above factors were taken into account, we only know when the tree was cut down (when it stopped taking up CO2) we have no idea how long it might have sat around before being used in a fire. Therefore, unfortunately, we cannot tell when the fire occurred with the limited data given.
Measured with radioactivity or AMS methods Current Carbon-14 Fraction Original Carbon-14 Fraction R = Measured using a contemporary reference sample R
Warning! Astrophysicist Talking about Tree-Rings!
Correcting Carbon-14 With Tree Rings
Current Carbon-14 Fraction Original Carbon-14 Fraction R = R Estimated Age Estimated Ratio
Current Carbon-14 Fraction Original Carbon-14 Fraction R = R Estimated Age Actual Age Estimated Ratio Actual Ratio
Warning! Astrophysicist Talking About Archaeology
Glaciers around 12,000 BP Clovis Mammoth kills Clovis and the Ice-Free Corridor
Are there Sites earlier than Clovis?
Dates at Meadowcroft 1775 AD 1265 AD 1025 AD - 660 AD 285 AD - 125 BC 340 BC - 870 BC 980 BC -1305 BC 1260 BC - 6060 BC 10,850 BC - 14,255 BC +
What is really Important about Monte Verde
Rather than: How did people get into the New World? Mammoth Hunters How did people live in the New World? Forest Foragers
Next Time Potassium, Argon, Genes and Walking Upright