"We know from atmospheric measurements over the last 50 years that radiocarbon levels vary through the year, and we also know that plants typically grow at different times in different parts of the Northern Hemisphere.
So we wondered whether the radiocarbon levels relevant to dating organic material might also vary for different areas and whether this might affect archaeological dating." The authors measured a series of carbon-14 ages in southern Jordan tree rings, with established calendar dates between 16 A. They found that contemporary plant material growing in the southern Levant shows an average offset in radiocarbon age of about 19 years compared the current Northern Hemisphere standard calibration curve.
Radiocarbon, or carbon 14, is an isotope of the element carbon that is unstable and weakly radioactive. Carbon 14 is continually being formed in the upper atmosphere by the effect of cosmic ray neutrons on nitrogen 14 atoms.
It is rapidly oxidized in air to form carbon dioxide and enters the global carbon cycle.
The impact of the radiocarbon dating technique on modern man has made it one of the most significant discoveries of the 20th century.
No other scientific method has managed to revolutionize man’s understanding not only of his present but also of events that already happened thousands of years ago.
Click on each point to view radiocarbon data report. Additional samples from other perishable artifacts from Ceremonial Cave have been submitted for radiocarbon dating and results will be added to this exhibit as findings become available.
The intact condition and excellent preservation of the hafted dart points from Ceremonial Cave made them exceptional candidates for radiocarbon dating. CT scans reveal that the chipped-stone dart points are expanding stem varieties tentatively classified as type The three classified as Carlsbad are dated to 400 B.
by contributing institutions or for the use of any information through the Eurek Alert system.
Small samples were removed from the wood foreshaft on three specimens and the wrapping material on one and submitted to Beta Analytic Inc. Two samples received the standard pretreatment and analysis and two received a solvent extraction to remove any potential preservative/pesticide contamination. For those samples not large enough for 13C/12C ratio measurement, a ratio including both natural and laboratory effects was measured during the 14C detection to derive a conventional radiocarbon age suitable for applicable calendar calibration.
For each of the sampled specimens, both conventional and calibrated dates were calculated and results plotted on a graph.
Radiocarbon dating is essentially a method designed to measure residual radioactivity.
By knowing how much carbon 14 is left in a sample, the age of the organism when it died can be known.