How do they know the meteorite crater is 50,000 years old?

Hi All,

This was a question from the lecture relating to the Barringer crater: http://www.barringercrater.com/education/craterfacts.php

Here is one way to do it: http://en.wikipedia.org/wiki/Radiometric_dating

Apparently scientists also use a technique called "relative dating" which assumes new rock layers are found on top of old rock layers.

It would be interesting to build some of this into your islands.

Cheers