[mitthrowaway2]

> OSL measures when minerals such as quartz were last exposed to sunlight. Over time, these minerals build up a tiny store of energy while buried. When stimulated with light or heat in the laboratory, the minerals release this energy as a faint glow, which tells experts how long they have been underground.

Now that's just magic, plain and simple.

[bsder]

TIL. And that petrified mud wasp nests can be used to date things. Wild.

https://en.wikipedia.org/wiki/Optically_stimulated_luminesce...

[aa-jv]

It sure is. Plus, a little math:

Age (years) = Equivalent dose (Gy) ÷ Dose rate (Gy per year or Gy/ka)