gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1998.62A.1.220 Precise two Chronometer Dating of Pleistocene Travertine: The ²³⁰Th/²³⁴U and ²²⁶Ra_ex/²³⁴U Approach Eikenberg J. Vezzu G. Paul Scherrer Institute, 5232 Villigen (PSI), Switzerland Wyssling G. Buero Wyssling AG, 8803 Pfaffhausen (ZH), Switzerland 1998 62A 1 417 418 Copyright © 1998, The Mineralogical Society 1998