Infrared Spectroscopic Biosignatures from Hidden Cave, New Mexico: Possible Applications for Remote Life Detection

Abstract

Subsurface environments are known to support and preserve diverse microbial communities. Giant pool fingers from Hidden Cave, New Mexico consist of mm-scale dark micritic calcite layers alternating with clear dogtooth spar crystals and contain morphological and geochemical evidence of past microbial communities. We used Fourier Transform infrared spectroscopy to identify fatty acids, proteins, PO₂-carrying compounds, and polysaccharides spatially related to morphological fossil filaments throughout the surface micritic laminations and central pool finger regions. These biomolecular signatures are important components that contribute to the biosignature suite under development that identify microbial involvement in carbonate precipitation on Earth and remotely.

Keywords:

• biosignatures
• caves
• life detection
• spectroscopy

Acknowledgments

We thank the U.S. Forest Service for permission to sample in Hidden Cave. Dr. Kenneth Ingham kindly provided the cave photography.

Additional information

Funding

Funding for the lead author during data acquisition was through the Center for Planetary Science and Exploration (CPSX) at Western University, London, ON. Current funding is gratefully provided by the Science and Technology Facilities Council, UK. Funding for the initial Hidden Cave study was provided by the WIU University Research Council.