Open AccessA Study in Blue: Secondary Copper‐Rich Minerals and Their Associated Bacterial Diversity in Icelandic Lava Tubes
Author(s) -
Kopacz Nina,
Csuka Joleen,
Baqué Mickael,
Iakubivskyi Iaroslav,
Guðlaugardóttir Hrefna,
Klarenberg Ingeborg J.,
Ahmed Mahid,
Zetterlind Alexandra,
Singh Abhijeet,
ten Kate Inge Loes,
Hellebrand Eric,
Stockwell Brent R.,
Stefánsson Árni B.,
Vilhelmsson Oddur,
Neubeck Anna,
Schnürer Anna,
Geppert Wolf
Publication year - 2022
Publication title -
earth and space science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.843
H-Index - 23
ISSN - 2333-5084
DOI - 10.1029/2022ea002234
Subject(s) - lava , astrobiology , martian , geology , mars exploration program , life on mars , geochemistry , copper , volcano , chemistry , biology , organic chemistry
Lava tubes on Mars hold exciting potential for the preservation of biosignatures, which may survive on geological timescales in these isolated, stable environments. To support the development of future astrobiological mission concepts, we turn to terrestrial lava tubes, host to a variety of microbial communities and secondary minerals. Following a multidisciplinary sampling protocol, we retrieved biological, molecular, and mineralogical data from several lava tubes in Iceland. We report on blue‐colored copper‐rich secondary minerals and their associated bacterial communities using a multi‐method approach, and an amalgam of 16S rRNA gene sequencing, Raman spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy data sets. We found numerous bacterial genera known for their high metal resistance and ability to survive in low‐nutrient environments. Both are characteristics to be expected for any potential life in Martian lava tubes, and should be considered when checking for contaminants in Mars mission preparations. Associated with the microbial mats, we identified several types of copper‐rich secondary minerals, indicating localized copper enrichments in the groundwater, possibly stemming from overlying ash deposits and nearby hyaloclastite formations. Molecular analysis revealed carotenoid signals preserved within the copper speleothems. If found in Martian lava tubes, blue copper‐rich mineral precipitates would be deserving of astrobiological investigation, as they have potential to preserve biosignatures and harbor life.