However, carbon dating has done well on young material like the Dead Sea Scrolls, the Minoan ruins, and acacia wood from the tomb of the pharoah Zoser.Some corals can be carbon dated, and also dated by another radioactive material, Thorium-230.Acetone is sometimes used while extracting fossils, because it dissolves dirt.In short, unless you have evidence to the contrary, you should assume that most of the carbon in a fossil is from contamination, and is not originally part of the fossil. The nuclear tests of the 1950's created a lot of C14.(Specifically, neutrons hit nitrogen-14 atoms and transmute them to carbon.) Land plants, such as trees, get their carbon from carbon dioxide in the air. The same is true of any creature that gets its carbon by eating such plants. Suppose such a creature dies, and the body is preserved.The C14 will undergo radioactive decay, and after 5730 years, half of it will be gone. So, if we find such a body, the amount of C14 in it will tell us how long ago it was alive. The method doesn't work on things which didn't get their carbon from the air.Also, humans are now burning large amounts of "fossil fuel".
Here is a list of suggestions of things that need to be done.However, even this small an adjustment was a bit of a shock.For example, Stonehenge suddenly became older than the Pyramids, instead of younger.Since then, several other calibrations have been done, which confirm and extend the tree-ring one.Some were done by finding lakes with atmospherically derived carbon in their annual layers of silt (called varves).