HYDRO26197

• Permit No: C1980007
• IBM Index Class Name: Hydrology
• Doc Name: APPENDIX A ISOTOPE ANALYTICAL LABORATORY REPORTS
• Permit Index Doc Type: OTHER GROUND WATER
• Media Type: D
• Archive: No

GEOCHRON LABORATORIES
a division of Krueger Enterprises, Inc.
711 CONCORD AVENUE + CAMBRIDGE, MASSACHUSETTS 02138-1002 + U . S . A
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RADIOCARBON AGE DETERMINATION REPORT OF ANALYTICAL WORK
Our Sample No. GX-24798-PRI
Your Reference: Mountain Coal Company/West Elk Mine
Submitted by: Mr. Erik C. Petersen
Mayo & Associates
710 East 100 North
Lindon, Utah 84042
Date Received: 1 0/30/98
Date Reported: 1 1/ 2 1/ 9 8
Sample Name: West Elk Mine: G-14
•AGE = 2,240 ± 390 14C years BP (13C corrected).
(75.67 t 3.69) °~ of the modern (1950) ~ 4C activity.
Description: Sample of groundwater precipitate.
Pretreatment: The barium salt precipitate was rapidly vacuum filtered and immediately hydrolyzed,
under vacuum, to recover carbon dioxide from the barium carbonates for the analysis.
13C analysis was made on a small portion of the same evolved gas.
Comments:
S13CPDB = -11.4 °,G.
Notes: This date is based upon the Libby half life (5570 years) for 14C. The error stated is t ie as judged by
the analytical data alone. Our modern standard is 95% of the activity of N.B.S. Oxalic Acid.
The age is referenced to the year A.D. 1950.
C~
SPECIALISTS IN GEOCHRONOLOGY 8 ISOTOPE GEOLOGY