Pushing it Back

[stickmaker]

A new method of calibrating Carbon 14 dating back to 52k years has been developed using lakebed sediment cores. As with tree rings, each year leaves a distinct layer. If there's a leaf or other bit of organic matter trapped in a layer, you can count back to the year in the core then carbon date the organic matter to calibrate. Find a lake with undisturbed sediments going back far enough...

Here's a link to more information:

http://www.terradaily.com/reports/Japanese_lake_record_improves_radiocarbon_dating_999.html