A Natural Fission Reactor

The evidence supporting the establishment of the zones of a natural fission reactor that occurred about 2 billion years ago is presented. The reactor evidence was found in an open-pit uranium mine in the southeastern part of the Gabon Republic, near the Equator on the coast of West Africa. The history of the probable sequence of events leading to the reaction is recounted. Reasons for the ceasing of the fission reaction are set forth. The spectrum of fission products in the area is thought to be so distinctive that it serves as an unmistakable sign that a chain reaction has taken place. Geological features of the area are related to conditions before and after the fission took place. (BLM)