TY - JOUR
T1 - Biomolecules from fossilized hot spring sinters
T2 - Implications for the search for life on mars
AU - Teece, Bronwyn L.
AU - George, Simon C.
AU - Djokic, Tara
AU - Campbell, Kathleen A.
AU - Ruff, Steven W.
AU - Van Kranendonk, Martin J.
N1 - Funding Information:
B.L.T. was supported by an Australian Government Research Training Program Scholarship. Funding for this project comes from an Australian Research Council Discovery Grant to M.J.V.K., and samples were collected during research conducted by K.A.C. supported by a Royal Society of New Zealand Marsden grant.
Publisher Copyright:
© Mary Ann Liebert, Inc., publishers 2020.
PY - 2020/4
Y1 - 2020/4
N2 - Hot spring environments are commonly dominated by silica sinters that precipitate by the rapid cooling of silica-saturated fluids and the activity of microbial communities. However, the potential for preservation of organic traces of life in silica sinters back through time is not well understood. This is important for the exploration of early life on Earth and possibly Mars. Most previous studies have focused on physical preservation in samples <900 years old, with only a few focused on organic biomarkers. In this study, we investigate the organic geochemistry of hot spring samples from El Tatio, Chile and the Taupo Volcanic Zone, with ages varying from modern to ∼9.4 ka. Results show that all samples contain opaline silica and contain hydrocarbons that are indicative of a cyanobacterial origin. A ∼3 ka recrystallized, quartz-bearing sample also contains traces of cyanobacterial biomarkers. No aromatic compounds were detected in a ∼9.4 ka opal-A sample or in a modern sinter breccia sample. All other samples contain naphthalene, with one sample also containing other polyaromatic hydrocarbons. These aromatic hydrocarbons have a thermally mature distribution that is perhaps reflective of geothermal fluids migrating from deep, rather than surface, reservoirs. These data show that hot spring sinters can preserve biomolecules from the local microbial community, and that crystallinity rather than age may be the determining factor in their preservation. This research provides support for the exploration for biomolecules in opaline silica deposits on Mars.
AB - Hot spring environments are commonly dominated by silica sinters that precipitate by the rapid cooling of silica-saturated fluids and the activity of microbial communities. However, the potential for preservation of organic traces of life in silica sinters back through time is not well understood. This is important for the exploration of early life on Earth and possibly Mars. Most previous studies have focused on physical preservation in samples <900 years old, with only a few focused on organic biomarkers. In this study, we investigate the organic geochemistry of hot spring samples from El Tatio, Chile and the Taupo Volcanic Zone, with ages varying from modern to ∼9.4 ka. Results show that all samples contain opaline silica and contain hydrocarbons that are indicative of a cyanobacterial origin. A ∼3 ka recrystallized, quartz-bearing sample also contains traces of cyanobacterial biomarkers. No aromatic compounds were detected in a ∼9.4 ka opal-A sample or in a modern sinter breccia sample. All other samples contain naphthalene, with one sample also containing other polyaromatic hydrocarbons. These aromatic hydrocarbons have a thermally mature distribution that is perhaps reflective of geothermal fluids migrating from deep, rather than surface, reservoirs. These data show that hot spring sinters can preserve biomolecules from the local microbial community, and that crystallinity rather than age may be the determining factor in their preservation. This research provides support for the exploration for biomolecules in opaline silica deposits on Mars.
KW - Biomarkers
KW - Cyanobacteria
KW - Hot springs
KW - Sinter
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U2 - 10.1089/ast.2018.2018
DO - 10.1089/ast.2018.2018
M3 - Article
C2 - 32155343
AN - SCOPUS:85082542721
VL - 20
SP - 537
EP - 551
JO - Astrobiology
JF - Astrobiology
SN - 1531-1074
IS - 4
ER -