"Dino-radiation?" -Reply

[FRAMEP@ORAU.GOV]

Mark:

NaI detectors have been utilized for quite some time to locate dinosaur
remains (there was a thread on Radsafe a couple of years back about
this very subject). In fact, the radioactivity of these fossils can cause a
little bit of a problem for some museums.

I don't pretend to know the chemistry involved, but the idea is more or
less as follows. Uranium in the groundwater exchanges with minerals in
the bones and the minerals that replace the bones. i.e. the minerals that
create the fossil. The greater the amount of uranium around, the higher
the activity. Obviously, Colorado is one area where dinosaur remains
can be expected to contain substantial quantities of uranium. We have a
couple of fossils from the Museum of Western Colorado that are quite
warm. Within one minute we can obtain a beautiful spectrum of the
uranium series counting one of these 20 cm away from a 10%
germanium detector!

Its not just dinosaur fossils either. Some fossilized remains of trees can
be easily detected with a NaI survey instrument (I have some fossilized
wood like this from Moab Utah). It also common to hear about fossilized
whale bones being radioactive. I've heard, but can't cite any references,
that human bones will accumulate uranium over time and that some
attempts have been made to date them using the uranium content. This
approach to dating sounds somewhat implausible however.

Fun stuff

Paul Frame
Professional Training Programs
ORISE
framep@orau.gov

Forget Clinton, Dole and Perot. Boney for President!