Pyramids carbon dating project
It's saying the average emission of Radium 226 for most building materials is: 50 bq.kg-1 (And I am not going to try and pretend that I know what that unit designation means....) The limestone in Egypt was between 79 and 99. So I guess it's not really that strongly radioactive.
Radium 226 is the isotope that can, rarely, affect C14 levels.
There's a lot you can get out of a piece of wood before you burn it to make lime or whatever. But if they're spread out, then that means all or most of the mortar has to be from the same year.
If we assume each boat carried one stone (since they were approximately 2.5 tones), that is an average of 100 stones per ten days, or 10 stones per day. I can't find a good number for the estimated number of casing stones that were used, but some sites put it at 144,000. Or 39.45 years of it anyway (I think maybe the camp was there longer?
The Great Pyramid has been carbon dated by dating some of the mortar in the layer below the outer stones. However, the dates ended up being 374 years too early. Then I remembered an article I had read once about granite being radioactive. en...-14_sources And then I happened to stumble on to this weird paper out there in the void of the internet that discussed the radio active properties of limestone from Upper Egypt.
A guy named Mike Lehrner crawled over the outside of the pyramid finding stones that had been slightly mis-cut and had parts filled in with mortar, and scraped some usable charcoal and other materials out of it. So I did a search and found something, but it basically said all rocks are mildly radioactive. It is highly technical, but if you skip to the end where they give their conclusions they mention that, although it falls within acceptable levels (not dangerous to human inhabitants of the buildings), the three isotope emission risks are: Thorium 232, Potassium 40, and Radium 226. In most cases, Radium 226 is the result of the decay of Uranium 238, which is found in trace amounts in most rocks.
The other I've read is that Carbon 14 dating is just unreliable (and that this finding is the reason it has been called into question.) Let me put you on another track.
What if you aged the Statue of liberty, to find out how old she was.
Maybe from tearing down a really big palace or a whole city and retasking the support beams? If they were just gathering old scraps from all over, then the dates would vary wildly. The recently found Merer diary from a guy in charge of moving the stones is the strongest evidence so far tying the pyramid to Khufu, but it only describes the moving of casing stones from the Tura quarry 8 miles away.