[DrDavid]

There was an article about this in Scientific American about 20 years ago.

I remember that article too!

This clearly demonstrates that nuclear fission reactors are more natural than internal combustion engines!

[nightdriver]

"This clearly demonstrates that nuclear fission reactors are more natural than internal combustion engines!"

I wouldn't have wanted to be near it when it was reacting, however!!

The authors of the article postulated that the critical mass was obtained when uranium salts were washed down this ancient stream bed and concentrated in a whirlpool or something.

It attracted the attention of the nuclear community when it was discovered that the U²³⁵ content at this location was only 0.4% instead of the more universal 0.7% found in uranium ores worldwide.

They called it evidence that nature had indeed formed a nuclear reactor.