Tim-
  I have measured 13C/12C ratios in pollen extracted from lake sediments
following the method of Brown et al (QR 32:205-212, 1989).  It is time
consuming but looks promising especially with additional cleanup using
sodium polytungstate density separations rather than picking out any
extraneous material by hand.
 I've also analyzed some modern lodgepole pine and Douglas fir samples
from the Pacific Northwest which had been treated to remove the inner
material.  Those values ranged from -28 to -30 o/oo.  Hopefully these will
be published soon as part of my dissertation.
Best wishes,
Paula


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On Thu, 31 Jul 1997, Tim Heaton wrote:

> Apologies if this question has been asked before:
>
> Have any attempts been made to analyse the 13C/12C of pollen?
>
> Tim Heaton
> NERC Isotope Geosciences Lab
> Keyworth
> Nottingham NG12 5GG, UK
>
> E-mail [log in to unmask]
>