RECONNAISSANCE GEOBIOLOGY SURVEY OF A POTENTIAL MARS ANALOGUE SITE, CAPULIN VOLCANO NATIONAL MONUMENT, NM

Volcanic caves are key targets for the search for life on Mars. Volcanic caves can provide shelter from a rapidly shifting outside environment, and the basaltic walls provide potential chemical energy resources, allowing life to prosper in an otherwise harsh environment. Lava tubes contain diverse microbial communities containing organotrophic and lithoautotrophic microorganisms, and neutrophilic iron-oxidizing bacteria have been documented to survive on olivine that occurs in basalt (Popa et al. 2012, Astrobiology v. 12, DOI: 10.1089/ast.2011.0639). The low light and Fe-mineral-rich conditions of Earth’s volcanic caves are thought to be similar to Martian lava tubes, which makes them compelling candidates in the search of extraterrestrial life. Capulin Volcano National Monument (CAVO) contains several lava flow fields deposited during the last Tertiary volcanic activity within the Raton-Clayton volcanic field, NM. The lava flows contain possible relict collapsed lava tubes and small volcanic and talus caves throughout the exposed trachybasalt outcrops. The diverse cave types and geometries at CAVO provide an opportunity to investigate microbial diversity in a variety of volcanic cave environments. We conducted a pilot study of the caves and their existing microbial communities that, to our knowledge, represents the first survey of the geobiology of volcanic caves at CAVO. We compiled cave coordinates, descriptions, and several maps, and then collected samples of cave walls and sediments for microbiological analysis. In the lab, DNA extraction and PCR analysis reveal low biomass microbial communities and confirmed the presence of life. In ongoing analyses, we will evaluate SSU 16S rRNA gene libraries to compare microbial communities from different cave locations and substrates, and quantify microorganisms using fluorescent microscopy. We will use this data to compare microbial communities from CAVO to similar microbial communities from well-studied lava tubes and other volcanic caves.