Greetings One and All, Do any of you have experience using lead isotopes for groundwater dating? Are there any references available? Thanks in advance for your assistance. Cheers! Julie Julie K. Sueker, Ph.D. Hydrologist Exponent Environmental Group 4940 Pearl East Circle, Suite 300 Boulder, CO 80301 [log in to unmask] http://www.exponent.com/ phone: (303) 444-7270 fax: (303) 444-7528