Micro- to nanoscale Molecular, Mineralogical, Morphological and isotopic identification of Micro and Macro-fossils
We aim at constraining the co-evolution of life and the environments on early Earth, targeting five milestones through life evolution (between 3.4 Ga – 400 Ma, Billion-Million years) linked with important changes in redox conditions and oxygenation.
Identifying the fossils of these times has been limited by:
- morphological simplicity,
- non-diagnostic organic carbon isotope ratio,
- difficulty to correlate individual fossils with molecular biomarkers analyzed on bulk rocks,
- difficulty to correlate fossils with geochemical metabolic/environmental proxies from bulk rocks.
To overcome these limitations, we will use a combination of micro- to nanoscale characterizations of fossils:
- We will develop novel microscale molecular methods: Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), and microscale Laser-desorption Laser-ionization Mass Spectrometry (µL2MS). Thanks to these innovative techniques we will be able, for the first time, to retrieve molecular information (biomarker and fossil biopolymer composition) on single fossil cells, and to distinguish adjacent cells as well as cell anatomy. These spatially-resolved analyses will identify possible in-lab and weathering contaminations.
- Complementary nanoscale analytical (spectro)microscopy will be used to analyze anatomy as well as mineral structures informing on post-mortem morphological modifications and biominerals.
- Metabolic signatures will be investigated using microscale and bulk-rock isotope analyses of organic matter and biominerals.
The project builds on the gathered participants’ expertise in the fields of organic and isotope geochemistry, paleontology, nano-mineralogy, mass spectrometry and spectroscopy, and analytical developments.