ABSTRACT

Argon dating of alunite in the Guadalupe caves by Polyak et al. (1998) shows consistently increasing age with elevation. Since the alunite is a by-product of the speleogenetic process, these dates indicate the true ages of the caves. The highest levels are 12 million years old, indicating that most tectonic uplift took place since then. Ages decrease downward at a decelerating rate, indicating a decrease in uplift rate and watertable decline with time. The lowest dated cave level is the Big Room of Carlsbad Cavern, at about 4 million years old.