I doubt they know what they are talking about. You can’t use carbon dating on rocks. It only works on dead, but former living, things:
Carbon-14 is an unstable isotope of carbon, Carbon-12 being the stable form. Living things, being made of carbon to a large extent, have a ratio of carbon-12 to carbon-14 which is the same throughout life. But once they die and stop eating, the carbon-14 decays slowly to an isotope of nitrogen, with a half-life of maybe 6000 years. Of course, the nitrogen goes into the atmosphere. Over time, the ratio changes to have more and more carbon-12 represented. After some years, all of the carbon-14 has decayed, leaving only carbon-12 represented. After that time, carbon dating is not available.
It is more likely that Stonhenge was built right where it is now, using rocks quarried from another place. Probably the heavy stones were moved just the same way as the blocks that make up the pyramids, by extraterrestrials. LOL.
Ah...like the American Constitution
[snip] Radiocarbon-dating of burnt hazelnuts and charcoal from the quarry-workers’ camp fires reveals that there were several occurrences of megalith-quarrying at these outcrops. Stonehenge was built during the Neolithic period, between 4,000 to 5,000 years ago. Both of the quarries in Preseli were exploited in the Neolithic, and Craig Rhos-y-felin was also quarried in the Bronze Age, around 4,000 years ago. [/snip]
http://phys.org/news/2015-12-stonehenge-bluestone-quarries-miles-wales.html
http://cdn.phys.org/newman/csz/news/800/2015/stonehengebl.jpg
