Evidence for biological activity in mineralization of secondary sulphate deposits in a basaltic environment: implications for the search for life in the Martian subsurface

Abstract

Evidence of microbial activity associated with mineralization of secondary Na-sulphate minerals (thenardite, mirabilite) in the basaltic subsurface of Craters of the Moon National Monument (COM), Idaho were examined by scanning electron microscopy, X-ray diffraction, laser desorption Fourier transform ion cyclotron resonance mass spectrometry (LD-FTICR-MS), Fourier transform infrared spectroscopy (FTIR) and isotope ratio mass spectrometry. Peaks suggestive of bio/organic compounds were observed in the secondary Na-sulphate deposits by LD-FTICR-MS. FTIR provided additional evidence for the presence of bio/organic compounds. Sulphur fractionation was explored to assist in determining if microbes may play a role in oxidizing sulphur. The presence of bio/organic compounds associated with Na-sulphate deposits, along with the necessity of oxidizing reduced sulphur to sulphate, suggests that biological activity may be involved in the formation of these secondary minerals. The secondary Na-sulphate minerals probably form from the overlying basalt through leached sodium ions and sulphate ions produced by bio-oxidation of Fe-sulphide minerals. Since the COM basalts are one of the most comparable terrestrial analogues for their Martian counterparts, the occurrence of biological activity in the formation of sulphate minerals at COM has direct implications for the search for life on Mars. In addition, the presence of caves on Mars suggests the importance of these environments as possible locations for growth and preservation of microbial activity. Therefore, understanding the physiochemical pathways of abiotic and biotic mineralization in the COM subsurface and similar basaltic settings has direct implications for the search for extinct or extant life on Mars.

Laser Ionization Mass Spectrometry at 55: Quo Vadis?

“…This instrument was extensively used for the identification and characterization of organic matter, such as amino acids, and other characteristic biosignatures in geological samples in regard to the possible use of LIMS for the search of extraterrestrial life (Richardson et al, 2008;Kotler et al, 2008;Richardson et al, 2009Richardson et al, , 2013 and for the characterization of naturally occurring minerals, for example, of high-iron basalts analog to Martian basalts (Richardson et al, 2012).…”

“…The spectra of natural and synthetic jarosites showed the presence of a peak at m/z of 275 u, which was identified as a cluster ion of glycine and jarosite fragments, demonstrating the presence of glycine in the natural jarosite samples. Afterwards the study was extended to other amino acids (Richardson et al, 2009) and minerals (Richardson et al, 2013). Using this methodology, it was possible to provide evidence that certain mineral deposits are associated with biological activity, either directly or indirectly.…”

Interstellar Detection of O-protonated Carbonyl Sulfide, HOCS+

“…The pursuit of understanding the chemical reservoir of the interstellar medium (ISM) is a cornerstone of modern astrochemistry. At the heart of this quest is the investigation of molecules harboring sulfur (S), which play a key role in diverse aspects, from stellar nucleosynthesis and chemical evolution of galaxies (Perdigon et al 2021) to atmospheric chemistry in planets (Krasnopolsky 2012;Gómez Martín et al 2017;Chang et al 2023), or biological processes (April 1986), and they are considered essential ingredients for life on Earth (Richardson et al 2013;Todd 2022).…”

Fundamental Science and Engineering Questions in Planetary Cave Exploration

“…Pits, vents, fissures, and caves provide access to near surface geology and liquid oceans without the need for drilling or digging (Stamenković et al., 2019 ). On Mars, these features may provide access to preserved volatiles including water ice (Schörghofer, 2021 ; Williams et al., 2010 ), brines (D. M. Burt & Knauth, 2003 ), and organic matter (Richardson et al., 2013 ). More broadly, planetary SAPs may ultimately provide data on volatile delivery and climatic oscillations.…”