James,

You should know that Bob Clayton has been doing this for years!  Ask him or
Tosh Mayeda.

Hal

Dr. Haraldur R. Karlsson
Assistant Professor
Department of Geosciences
and Department of Chemistry and Biochemistry (Joint)

Mailing Address:
Department of Geosciences
Box 41053,Texas Tech University
Lubbock, TX 79409
USA


Phones -  (806)-742-3130 	Office
          (806)-742-3112 	Stable Isotope Laboratory

Fax -     (806)-742-0100

world-wide-web: http://www.ttu.edu/~geosc/