Funding
This research is part of two ERC-funded projects, led by Dr. Mark van Zuilen in Paris (TRACES), and Dr. Stefan Lalonde in Brest, France (EARTHBLOOM).
Silica Precipitation in Microbial Mats
How does a living microbial mat become a lithified microbialite, preserving biosignatures which can last for billions of years?
While many studies investigate initial silica precipitation on a cellular scale, the succeeding steps of mat silicification into microbialite formation remain poorly understood.
To clarify the roles of environment and biology on mat silicification, I am:
1) producing chemical micro-profiles of silicifying mats from El Tatio, Chile
2) using electron microscopy to examine physical and chemical properties of silicified mat layers
3) replicating field conditions in laboratory mat incubations to foster silica precipitation.
Preservation of Microbial Textures In Microbialites
When examining ancient microbialites, what textures indicate primary microbial activity, and which indicate post-depositional alteration?
The same burial processes which preserve microbialites also alter biosignatures. Experiments have tested the effects of gradual diagenesis at a cellular scale, but the persistence of larger, delicate fabrics such as former gas bubbles and microbial cones remains less well-understood.
To examine the effects of diagenesis on mineralized mat textures, I am:
1) simulating natural silica precipitation in laboratory incubations of various mat textures (planar, tufted, bubble-rich, etc.)
2) performing autoclave experiments on silicified mats to simulate burial temperatures and pressures
3) using petrography and electron microscopy to compare autoclaved samples with living mats and recent sinters
Sinter Cores as Sedimentary Records
