Hi, 
I am working on applications of stable isotope data (O-18 and 
C-13) to paleoclimatic/paleoenvironmental reconstruction from 
lake sediments in southern Ontario.  I have some questions 
regarding the use of mollusc shells for isotope analysis.
The aquatic molluscs I am going to use are Valvata sincera and 
Gyraulus parvus.

1. Usually how many miligrams of shells are needed for the 
analysis?  And will different amounts used give different 
results?

2. Any preference regarding the mollusc ecology for using 
as isotope analysing materials? e.g., shallow vs. deep water 
species, still vs. moving water species, etc.?

3. Any preference regarding the size in one species?  Will 
small and large individuals give different results due to 
their ages or habitats?

Any suggestions or references would be greatly appreciated.

Thanks.
Zicheng


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Zicheng Yu, Department of Botany, Royal Ontario Museum, Toronto, ON M5S 2C6
[log in to unmask]; Fax: (416) 586-5516; Phone: (416) 586-5609
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