Hi Greg,

Antarctic snow nitrate may hold the record : Blunier et al (GRL,  
2005) have found a maximum d15N of 200 ‰ in snow at 15 cm below the  
surface, at Dome C, Antarctica. See also Freyer et al. (Tellus, 1996)  
for high d15N in polar snow and ice. We've recently carried out  
measurements of nitrate from Dome C snow, and found out d15N values  
as high as 350‰ at 150 cm below the surface (M. Frey et al., in prep.).

References :

Freyer, H. D., Kobel, K., Delmas, R. J., Kley, D., and Legrand, M.  
R. : First results of 15N/14 N ratios in nitrate from alpine and  
polar ice cores, Tellus, 48B(1), 93 – 105, 1996.

Blunier, T., Floch, G. L., Jacobi, H.-W., and Quansah, E. : Isotopic  
view on nitrate loss in Antarctic surface snow, Geophys. Res. Lett.,  
32 (L13501), doi :10.1029/2005GL023011, 2005.

Cheers

Samuel

On Jun 11, 2008, at 12:53 AM, greg michalski wrote:

>> What are the highest reported d15N values in natural samples?
>
>
>
>
> Greg Michalski, Assistant Professor
> http://www.purdue.edu/eas/michalski/
> Department of Earth and Atmospheric Sciences
> Purdue University
> 550 Stadium Mall Dr.
> Lafayette IN.47907
>
>