Jena E. Johnson

Assistant Professor

Principal Investigator [CV]

I have long been fascinated by how the history and evolution of life on Earth are tied to the evolving climate and surface chemistry of our planet. I majored in Geobiology at Brown University and pursued a PhD in Geobiology at Caltech. My PhD investigated the evolution of photosynthesis and rise of atmospheric oxygen through the manganese mineral record. During the course of my thesis, I recognized the importance of performing laboratory experiments and studying field analogues in order to correctly interpret the rock record. I continued gaining expertise in linking aquatic chemistry with geomicrobiology in a postdoctoral position at the University of Colorado in Boulder. I began a faculty position in the Earth and Environmental Sciences department at U-Michigan in January, 2018.

Here at Michigan, I am focused on understanding how the evolution of life and environments are recorded in chemical signals safeguarded in the geologic record. We are working on projects to understand the potential geobiological signals hosted in chemical precipitates in the sedimentary record, and studying microbe-mineral interactions that could lead to the formation of these ancient geobiological signals.

Current Lab Members

Anisha Ghosh

Graduate Student

Anisha joined the microbe mineral lab in the fall of 2023 after completing her B.S. and Master’s degree in Geological Sciences at Jadavpur University, India. Throughout her life, Anisha has been fascinated by the ancient oceans and early life. Now as part of the Microbe-Mineral Lab, she is investigating the bioavailability of trace metals in ancient oceans. 

Anya Hall

Undergraduate Researcher

Anya is an Earth Science major who is passionate about the intertwined history of Earth and evolution of life. Anya is especially interested in oceanography and paleontology. Anya joined us in May 2024 to perform Raman spectroscopy analyses on iron formations and assist Leanne.

Leanne Rossi

Lab Manager

Leanne joined the Microbe-Mineral Lab as lab manager in 2022 to continue pursuing her interests in biogeochemistry and oceanography. With a background in aquatic chemistry, Leanne is aiding in the research pursuits of the lab as part of her work as lab manager & research technician!

Alice Zhou

Graduate Student

After joining the Microbe-Mineral Lab in Aug 2019, Alice is exploring whether photoferrotrophy can catalyze the precipitation of iron silicates and determining whether there are potential signatures of that biomineralization using a variety of characterization methods. This research will allow us to understand whether photoferrotrophy was involved in the formation of iron formations. She joined us from Dartmouth College where she obtained her M.S. degree working on extremophilic archaea and what exactly their preservable membrane lipids record about their activity.

Former Members of the Lab

Tessa Casselman (MS’24, Thesis: The effects of microbial iron reduction and silica on green rust in banded iron formations)

Kaitlin Koshurba (MS’23, Thesis: Braunite synthesized under simulated diagenetic conditions: Implications for the ancient manganese cycle), Undergrad Research Assistant Winter 2020, Research Tech 2020-2021, MS student 2021-2023

Ben Klein (BS’23) – Undergrad Research Assistant from Fall 2021 – Spring 2023; now at the EPA

Trinity Pryor (BS’22) – Undergrad Research Assistant from Fall 2020 – Spring 2023; now in environmental consulting

Isaac Hinz (MS’22, Thesis: Simulated Diagenesis of the Iron-Silica Precipitates in Banded Iron Formations, Lab Manager 2018-2020); now at the National Renewable Energy Laboratory (NREL)

Daniel Zammit (Lab Manager, 2021-22); now at Applied Environmental

Chrissie Nims (MS’21, Thesis: Exploring the impact of silica and divalent cations on microbial iron respiration and secondary mineral products in Archean ocean simulations); now environmental consultant at Wood 

Drake Yarian (Lab Manager, 2020-2021); now MS student at University of Cape Town

Sammy Theuer (BS’19, Honors Thesis: Iron-rich Silicate Clay Synthesis & Paleoenvironmental Implications for Early Earth and Mars); now MS student at Western Washington University

Photos