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发帖数: 76 | 1 One of Dr Richards' research interests is the calibration of radiobarbon
dating. This involves checking the dates using other independent methods. The
main source of systematic error in radiocarbon dating is the varying
concentration of carbon-14 in the atmosphere in the past. Dr Richards and his
colleagues have found good evidence of increased levels beyond about 30,000
years ago, with a very substantial peak around 43.3 to 44.3 thousand years
ago, by studies of a stalagmite.
They consider incr |
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