Re: Occupationally Exposed Paleontologists?

["Dale E. Boyce" <dale@radpro.uchicago.edu>]

I first learned about radioactive fossils a few years ago.  Paul
Sereno, the discovereer of Hererrasaurus (or something like that)
asked me to check H. out.  It measured as I remember about 2 mRem/hr
at contact with a thin end window GM (2,400 cpm).  The activity
was from uranium and its decay chain.  It seems that the uranium
phosphate is the culprit.  I am told that soluble uranium in ground
water is precipitated as phosphate by other more soluble phosphates
in the animal.  Since fossils are old, radium is in equilibrium and
its gamma-rays are evident in spectra of fossils that have been
exposed to significant uranium concentrations during the fossilization
process.

Dale E. Boyce  dale@radpro.uchicago.edu