Tullis Onstott, innovative Geologist, Explorer of Subsurface Life, and Revered 'Gentle Soul,' dies at 66

Denise Valenti, Office of Communications

Tullis Onstott, a Princeton graduate and professor of geosciences known for his innovative research in several specialties and his explorations of lifeforms deep below the Earth’s surface, died Oct. 19, 2021, in Oracle, Arizona, from complications associated with lung cancer. He was 66.

Tullis Onstott has been focusing his research for the last 23 years on subsurface microbial life. This research involves exploration of subsurface microbial ecosystems via mines, drilling, and new underground laboratories, and by quantifying their community structure, function, and activity. His group does this by analyzing metagenomes, metatranscriptomes and metaproteomes, performing stable isotope measurements, and combining geochemical measurements with thermodynamic models.

The principal focuses of his research projects are the activity and survival of bacteria and other microorganisms in the deep subsurface (> 0.5 km) of continents, in the shallow permafrost deposits in the polar region and in shallow aquifer sediments.   Among the questions his research group address are: 1) How do subsurface microorganisms evolve and what role do subsurface viromes play in evolution? 2) What constrains the diversity and abundance of microorganisms? 3) What role does radiation play as an energy source for life? 4) What types of organic compounds are utilized by subsurface microorganisms and by what processes? 5) How does the methane and nitrogen cycles interact in the subsurface? 6) How will global climate warming impact the methane cycle in the Arctic and in Antarctica. 7) What controls the upper temperature limit of life? 8) How do microbial redox processes control the migration of arsenic in groundwater?

Currently, his group is involved in four field projects, the first situated in the deepest mine in North America and the second sited in the world’s deepest mines in South Africa, the third in the Siberian permafrost deposits and the fourth in shallow groundwater sites in the state of New Jersey. These projects seek to address fundamental scientific questions regarding bacteria/rock/environment interactions while at the same time developing applications of this information that will benefit mankind. test

ORCID Profile

Image removed.https://orcid.org/0000-0002-2898-3374