[Coral-List] Vital effect

[Clare]

Dear List,
I am working on some Eocene Acropora from the Hampshire and Paris basins 
for my masters and particularly the paleoclimatic imformtion i can get 
from their preserved aragonite skeletons.  I have just got my carbon and 
oxygen results back and was andering how to make a 'vital effect' 
correction? I know this can be effected down to species levels but as i 
have abraded small fragments i wandered if there was a general 
correction i could apply on genus level?
Many thanks
Clare White