Carbon dating flaws wikipedia
Another common carbon flaw appears as a black shard or needle through the stone.
These flaws are regarded as undesirable in any stone, though the appearance of carbon flaws is more notable in white stones.
But that assumes that the amount of carbon-14 in the atmosphere was constant — any variation would speed up or slow down the clock.
The clock was initially calibrated by dating objects of known age such as Egyptian mummies and bread from Pompeii; work that won Willard Libby the 1960 Nobel Prize in Chemistry.
The blemish may be microscopic or visible to the naked eye.The problem, says Bronk Ramsey, is that tree rings provide a direct record that only goes as far back as about 14,000 years.Marine records, such as corals, have been used to push farther back in time, but these are less robust because levels of carbon-14 in the atmosphere and the ocean are not identical and tend shift with changes in ocean circulation.Take the extinction of Neanderthals, which occurred in western Europe less than 30,000 years ago.Archaeologists vehemently disagree over the effects changing climate and competition from recently arriving humans had on the Neanderthals' demise.