# Question about carbon dating **URL:** \ **Category:** Factual Questions\ **Created:** [March 5, 2010, 4:02pm UTC](https://boards.straightdope.com/t/question-about-carbon-dating/531425 "2010-03-05T16:02:03Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![ratatoskK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ratatoskk/32/2987_2.png) [@ratatoskK](https://boards.straightdope.com/u/ratatoskK)\ **Post date:** [March 5, 2010, 4:02pm UTC](https://boards.straightdope.com/t/question-about-carbon-dating/531425/1 "2010-03-05T16:02:03Z")
[This article](http://www.tcpalm.com/news/2010/mar/04/scientists-urge-full-scale-excavation-of-vero/) discusses dating some human bones found in the ground in Florida. They were originally excavated in 1915 and there are plans to do more digging. About the already recovered bones, the article says: > [@](#): > > But because the bones lost all their carbon while in the ground, they can’t be dated using modern radiocarbon dating I don’t understand why being in the ground would hamper carbon dating. I thought this stuff was always found in the ground. Can someone explain this? ---
**Author:** ![Floater](https://avatars.discourse-cdn.com/v4/letter/f/dc4da7/32.png) [@Floater](https://boards.straightdope.com/u/Floater)\ **Post date:** [March 5, 2010, 4:09pm UTC](https://boards.straightdope.com/t/question-about-carbon-dating/531425/2 "2010-03-05T16:09:41Z")
My guess is that they have fossilised and the organic contents have been replaced with minerals and turned to stone. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 5, 2010, 4:29pm UTC](https://boards.straightdope.com/t/question-about-carbon-dating/531425/3 "2010-03-05T16:29:39Z")
The main mineral structure of bone is calcium phosphate. When bones are buried, the organic materials in them can be dissolved away and replaced by minerals in the process of [petrification or permineralization.](http://science.jrank.org/pages/15064/fossil.html) Carbon dating of course can only be done if the bone retains its original carbon. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [March 5, 2010, 5:06pm UTC](https://boards.straightdope.com/t/question-about-carbon-dating/531425/4 "2010-03-05T17:06:14Z")
> [@Floater](#): > > My guess is that they have fossilised and the organic contents have been replaced with minerals and turned to stone. Nope. Not in only 100 years. Takes milliions and millions. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [March 5, 2010, 5:27pm UTC](https://boards.straightdope.com/t/question-about-carbon-dating/531425/5 "2010-03-05T17:27:04Z")
> [@CC](#): > > Nope. Not in only 100 years. Takes milliions and millions. Nope. 5-10 years is sufficient in the ideal circumstances ([cite](http://www.dinosauria.com/jdp/fossil/fossil.htm)) Of course, it’s also possible that all of the organic content simply decayed away. Once bacteria and such get in there, you can’t trust the age of the carbon that’s left to be representative of the original artifact’s age. Water would be relevant to this only as far as it helps support decay. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [March 5, 2010, 5:30pm UTC](https://boards.straightdope.com/t/question-about-carbon-dating/531425/6 "2010-03-05T17:30:46Z")
> [@CC](#): > > Nope. Not in only 100 years. Takes milliions and millions. Incorrect. Did you read the article linked to in the OP? The bones have been in the ground for at least 11,000 years, which is sufficient time for mineralization to have taken place. It certainly does not require “millions and millions.” While mineralization/fossilization can take a long time (often thousands of years), under some conditions it can happen rapidly. From [here (pdf):](http://www.aaps-journal.org/submission%20pdf/How%20to%20Make%20a%20Fossil.pdf) > [@](#): > > We don’t know how long it took for fossilization of the Stegosaurus skeleton to occur. Experimental work I have conducted has shown that the process does not necessarily take very long (Carpenter 2005). Under ideal situations, a dinosaur could be fossilized in only a few years. The rate seems dependent upon the supply of dissolved atoms and molecules in the water available for bacterial use. This in turn is dependent upon the replenishment rate of the water. The rate is faster for bone buried in sand than for bone buried in mud, because ground water can flow more freely around the sand grains than around the clay particles. ---
**Author:** ![Arkcon](https://avatars.discourse-cdn.com/v4/letter/a/96bed5/32.png) [@Arkcon](https://boards.straightdope.com/u/Arkcon)\ **Post date:** [March 5, 2010, 5:33pm UTC](https://boards.straightdope.com/t/question-about-carbon-dating/531425/7 "2010-03-05T17:33:22Z")
The article in question also seems to imply that they are fragments, collected 100 years ago, possibly handled improperly. It may not be that these fragments can’t be carbon dated, just that, for some reason or another, no one wants to. Carefully checking to find an uncontaminated, organic-rich fragment may just not be a sellable idea.