Speleothem Studies Extend 14C Calibration
Speleothems (such as stalagmites) are calcium carbonate deposits that form from drips in limestone caves. Individual speleothems can be tens of thousands of years old. Scientists are attempting to extend the record of atmospheric carbon-14 by measuring radiocarbon in speleothems which have been independently dated using uranium-thorium dating. These results are improving the calibration for the radiocarbon technique and extending its usefulness to 45,000 years into the past. Initial results from a cave in the Bahamas suggested a peak in the amount of carbon-14 which was twice as high as modern levels. A recent study does not reproduce this extreme shift and suggests that analytical problems may have produced the anomalous result.
Read more about this topic: Radiocarbon Dating
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