Re: EXTINCTION=> Iridium in Fish Teeth?

[xm9@sdcc12.UCSD.EDU (richard g. adair)]

> Don't forget that iridium is not inert. It can be remobilized and
> concentrated by microbal and/or diagenetic processes.

I've just read a summary of an article which used strontium isotope 
levels in late Jurassic fish teeth to infer ocean crust creation rates. 
I think the operative mechanism here is the molecular similarity
between strontium and Ca in the very stable apatite of the teeth.
I was wondering if anybody knew if fish teeth could also uptake Ir,
and thus provide another line of evidence for the impact scenario. 
If, further, there is sufficient K/Ar in the teeth, this might
permit fine-scale dating.