Characterisation of the bio-mineralogical and isotope geochemical signatures of past life in a Mars analogue environment of Rio Tinto, SW of Spain
Abstract
Iron-rich sulfate minerals are present on Mars hence sulfur, oxygen and iron isotopes could be a key tool for the detection of any past or present life. Experiments with flow through reactors and enrichment cultures have been conducted to investigate the link between the activity of microbial communities and sulfur, oxygen and iron isotope fractionation in Martian like minerals. Sediments from a modern hyper-acidic, Fe-rich subareal environment at Rio Tinto, SW Spain were used in the experiments. This site has been frequently used as a geochemical analogue of Mars. Sediments were sampled from the upper part of Rio Tinto (Marismilla) and the estuary (Moguer). Laboratory incubations were carried out at 30°C, using an artificial input solution with sulfate in excess [1]. Initial data from the flow through reactor experiments indicate an extreme sulfur isotope fractionation in the Moguer estuarine part, extending beyond the maximum of 47‰ predicted by the standard Rees model [2]. These data suggest that, at least, sulfur isotopes have a potential to be sensitive indicators of biotic activity in Martian environments that contain sulfate minerals.
- Publication:
-
European Planetary Science Congress 2012
- Pub Date:
- September 2012
- Bibcode:
- 2012epsc.conf..579V