Microbialites record interactions between the biosphere and the geosphere for ~3.5 billion years and are the oldest fossils of life on Earth. Our ability to interpret these trace fossils hinges on our ability to properly interpret their texture (texture also provides critical context for interpreting their geochemistry). However, we don't completely understand which actions by microbial ecosystems or specific bacteria/archaea cause the mineral textures to form which end up preserved in the fossil record. As a result of an unreliable ability to interpret textures, texture itself can be considered an "unpromising" biosignature. If, however, our ability to interpret textures in fossils improved, the promise of texture as a biosignature might change in an exciting way.

I use fluorescently labelled embedded coring to reconstruct textures of microbes, minerals, and channel architecture within incipient microbialites in 2 & 3 dimensions on micron scales. I use a suite of microscopy techniques including epifluorescence and petrographic microscopy, coupled with microCT scanning at a voxel size of 2.1 microns. We have applied this technique to microbialites forming in Cone Pool, a Hot spring in Little Hot Creek, which is the subject of an in prep publication. However, we also use FLEC on other targets with support from the NASA Early Career Collaboration Award (thrombolites), the USC Wrigley Institute on Catalina Island (intertidal marine cyanobacterial mats), the Cnidarian Evolutionary Ecology lab in USC Marine and Environmental Biology (live corals), and Inyo National Forest (looking at arthropod taphonomy). These are ongoing projects and collaborations. 

Recent oral presentations about this project at AGU (Washington DC), GSA (Anaheim), Goldschmidt, and Life and Planet (London)