Initial Publication Date: October 17, 2006

Project Significance:

Created by George Rice, Montana State University

Intellectual Merit: The main question addressed by this research is whether the presence of terraced carbonate architecture is prima facie evidence for the presence of microbial activity. Results from this study will permit the identification of microbiologically influenced crystallization in other modern and ancient high-temperature and low-temperature terraced carbonate spring deposits. The techniques employed in the quantitative modeling provide a first principles understanding of significant geological features from a physical and biological perspective. Of equal importance, the results from this study will establish a systematic and quantitative tool kit to identify microbial influence during carbonate deposition that can be used in a wide variety of other important terrestrial, marine, and burial environments on earth and other planets.

Terraced architecture at Mammoth Hot Springs.

Mammoth Hot Springs is the most appropriate natural laboratory in the world for conducting this research. Although CO2 degassing and decreasing temperatures strongly influence the spring water chemistry, significant biological controls on travertine crystal form and isotope chemistry have recently been quantitatively documented. Mammoth Hot Springs uniquely offers: 

  1. Precipitation rates as high as 5 mm/day that allow short-duration in situ crystallization experiments in a regime of coupled biological and physical influences.
  2. A full spectrum of high- to low-temperature carbonate precipitates at one site.
  3. Long-term familiarity of the study site by the PI's who have all required research permits in hand.
  4. The only easily accessible hot spring complex of this kind in the world protected in its natural state.

Copyright on all images and material by Bruce Fouke, 2006.