While looking at thin sections from the Harkless Formation, I noticed many tiny spiraling organisms against the carbonate background. I soon learned they were Obruchevella, spiral cyanobacteria fossils. Examination under SEM-EDS revealed that they were silicified in a carbonate matrix, an unusual mode of preservation. I analyzed them using Raman spectroscopy and noticed that they still preserve organic matter.

I developed a taphonomic story to describe how these cyanobacterial fossils became silicified soon after death, relying on chemical and sedimentological information. 

Check out our paper for more details!