conodont apatite

["CN. Trueman" <C.N.Trueman@xxxxxxxxxxxxx>]

  Hello.
	(a good way of starting I thought).
  This is essentially for Cindy Wright, as the title may suggest. I'm a
PhD student in Bristol looking at various aspects of inorganic apatite
preservation. As well as other things I've done some work on REE's and
through that had a chat with Richard Aldridge who together with H.
Elderfield had a look at conodont Nd and REE's. What I'm getting with my
results so far supports what they suggested, that when you move from
conodont apatite to fish apatite, you lose the stability in REE
signatures. 
  I've not looked at isotopic signatures, so I've no idea what goes on
there, but I would be interested in any suggestions as to why conodont
apatite preserves REE signatures. (for instance, what is the crystal size
of conodont apatite? - and how close is it to stoichiometric apatite?)

P.S. can anyone give a really good reason why blood cells should never be
preserved?. In Archaeological material (I forget the age) from the East
Med region, blood cells were preserved mineralised, so that some
could be seen to be shattered under SEM. - they didn't give any chem.
analyses. 
  I agree you have to be careful with simple Fe concentrations.

  Have fun.
	Clive Trueman
	Dept. of Geology
	University of Bristol
	glcnt@bristol.ac.uk