Mars Rover Techniques and Lower/Middle Cambrian Microbialites from South Australia: Construction, Biofacies, and Biogeochemistry

Using laser micropyrolysis to assess potential relationships between Cambrian tommotiids and organophosphatic brachiopods

“…The pyrolysates of two Dailyatia specimens also contain phenanthrene, while the pyrolysates of A. toddense and M. etheridgei C-E contain phenanthrene and methylphenanthrenes. The MPI values that Teece et al [52] reported were <0.44, whereas the values reported here are between 0.42 and 0.73. The pyrolysates from each species have similar peak distributions relative to one another, and there are consistent differences between species.…”

“…The low Pr/n-C17 ratios (<0.5) and Ph/n-C18 ratios (<1.0) are typical of extracted samples in the oil generation window. Teece et al [52] reported similar Pr/n-C17 (<0.55) and Ph/n-C18 (<0.7) ratios from GC-MS of solvent extracted microbialite samples from younger Cambrian strata in the Flinders Ranges.…”

“…That study included samples from the Wilkawillina Limestone and the coeval Wirrapowie Limestone, but these were overmature and did not return diagnostic biomarker information using extract chemistry [52]. Through Raman spectrometry and the methylphenanthrene index (MPI) obtained through GC-MS, it was concluded that the least thermally mature samples in their study had burial temperatures of ~200°C, with thermal maturity decreasing through younger strata above the Flinders Unconformity (Wirrapowie > Wilkawillina > Wirrealpa limestones).…”

“…Through Raman spectrometry and the methylphenanthrene index (MPI) obtained through GC-MS, it was concluded that the least thermally mature samples in their study had burial temperatures of ~200°C, with thermal maturity decreasing through younger strata above the Flinders Unconformity (Wirrapowie > Wilkawillina > Wirrealpa limestones). The sample analysed from the Wilkawillina Limestone has a burial temperature of approximately 201-210°C [52]. While little is known about the thermal maturation of Cambrian small shelly fossils, many early-mid Palaeozoic organophosphatic fossils (e.g.…”

Compositional Remote Sensing and Hyperspectral Laboratory Analyses of Sinters in Hydrothermal Fields in Chile, With Relevance to Astrobiological Targets on Mars

“…For example, it has been suggested that life's essential elements and reactive mineral surfaces in impact craters of about 100 km in diameter could be available for up to a few million years, which would be long enough for the emergence of life (Westall et al, 2018). Hence, hydrothermal silica on Mars may be an optimal niche for preserving biosignatures, if life was once hosted on Mars, which could also serve as paleontological repositories that may aid understanding of controls on the origin of life on Earth (Cady et al, 2003(Cady et al, , 2018Campbell, Lynne, et al, 2015;Damer & Deamer, 2020;Farmer & Des Marais, 1999;Ruff et al, 2020;Teece et al, 2020Teece et al, , 2022Teece et al, , 2023Westall et al, 2015).…”