2016/11/17 by Steven W. Ruff, Jack D. Farmer · 9 citations
Physics and Astronomy · Earth and Planetary Sciences · #Planetary Science and Exploration #Paleontology and Stratigraphy of Fossils #Geology and Paleoclimatology Research #Mars Exploration Program #Hot spring #Impact crater #Geology #Fumarole #Martian #Astrobiology #Hydrothermal circulation #Regolith #Geochemistry #Volcano #Sedimentary rock #Spring (device) #Amorphous silica #Mineralogy #Chemical engineering #Paleontology
paper · pdf · doi:10.1038/ncomms13554
openalex publication_date 2016/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
O) in an ancient volcanic hydrothermal setting in Gusev crater. An origin via either fumarole-related acid-sulfate leaching or precipitation from hot spring fluids was suggested previously. However, the potential significance of the characteristic nodular and mm-scale digitate opaline silica structures was not recognized. Here we report remarkably similar features within active hot spring/geyser discharge channels at El Tatio in northern Chile, where halite-encrusted silica yields infrared spectra that are the best match yet to spectra from Spirit. Furthermore, we show that the nodular and digitate silica structures at El Tatio that most closely resemble those on Mars include complex sedimentary structures produced by a combination of biotic and abiotic processes. Although fully abiotic processes are not ruled out for the Martian silica structures, they satisfy an a priori definition of potential biosignatures.