title: Self-assembled silica-carbonate structures and detection of ancient microfossils.
abstract: We have synthesized inorganic micron-sized filaments, whose microstucture consists of silica-coated nanometer-sized carbonate crystals, arranged with strong orientational order. They exhibit noncrystallographic, curved, helical morphologies, reminiscent of biological forms. The filaments are similar to supposed cyanobacterial microfossils from the Precambrian Warrawoona chert formation in Western Australia, reputed to be the oldest terrestrial microfossils. Simple organic hydrocarbons, whose sources may also be abiotic and indeed inorganic, readily condense onto these filaments and subsequently polymerize under gentle heating to yield kerogenous products. Our results demonstrate that abiotic and morphologically complex microstructures that are identical to currently accepted biogenic materials can be synthesized inorganically.
authors: Instituto Andaluz de Ciencias de la Tierra, Consejo Superior de Investigaciones Científicas Universidad de Granada, Facultad de Ciencias, Campus de Fuentenueva 18002, Granada, Spain.
authors: J M
authors: JM
authors: García-Ruiz
authors: S T
authors: ST
authors: Hyde
authors: A M
authors: AM
authors: Carnerup
authors: A G
authors: AG
authors: Christy
authors: M J
authors: MJ
authors: Van Kranendonk
authors: N J
authors: NJ
authors: Welham
mesh_terms: D001315:Australia; D001464:Barium / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry*; D003460:Crystallization; D000458:Cyanobacteria; D018559:Exobiology; D005557:Formaldehyde / Q000737:chemistry; D005580:Fossils; D019015:Geologic Sediments / Q000737:chemistry*; D006838:Hydrocarbons / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D019369:Life; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008968:Molecular Conformation; D019800:Phenol / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D002254:Carbonates; D006838:Hydrocarbons; D005557:Formaldehyde; D001464:Barium; D019800:Phenol; D012822:Silicon Dioxide