>Hi Tim and Zicheng,

I am interested to hear about your research on freshwater molluscs. I have a
PhD student, Rowan White (E-mail: R.M.P. [log in to unmask]) working on an
experimental study of oxygen and carbon isotope fractionation in freshwater
molluscs. She is looking at two species: Lymnaea peregra and Vulvata
piscinalis. We have chosen these as they are common in British ponds and
lakes, also common throughout the UK Pleistocene and Holocene record and
because they spend their lifetime in water and not ephemeral puddles.

A few years ago we ran a pilot study using non-diagenetically altered
specimens from several UK sites. What became clear to us is that there is an
important species specific fractionation and also possibly an aging effect
in the isotope composition in the sense that juveniles might record a
slightly different composition to adults. Hence our experimental study. If
you are interested I can arrange for a report of the initial study to be
emailed to you.

Let me know what you think.

Best wishes,

Paul

P.F. Dennis
Stable Isotope Laboratory, University of East Anglia, Norwich, UK
>