ABSTRACT
Helium and lead are both present in the sun but no radioactive elements of higher atomic weights than lead are known to exist in it. An interesting sidelight on radioactive dating comes from a comparison of age figures compiled from the analyses of uraninite with figures of Goodman and Evens quoted in Dr. Rex’s article in the A. S. A. symposium. Granting the premise of uniform radioactive element formation at some distant period in the past and subsequent initial decay, let us say roughly three billion years ago, then follows, pari passu, that any radioactive mineral showing an age less than this has undergone modification and re-crystallization at a later date. Radioactive age dating research has largely been confined to minerals found in rocks the ages of which are assumed to be indicated by basic stratigraphical evidence. All radioactive minerals originally present in the rocks from which the comminuted material was derived must exist, even though widely disseminated.
