You still have to figure out when it did. If there's a tree with 800 rings, but it died 100,000 years ago, then there's 100,000 years you have to date by some o

You still have to figure out when it did. If there's a tree with 800 rings, but it died 100,000 years ago, then there's 100,000 years you have to date by some other method, and add 800 on top.