Selenium may support deep microbial life in Earth's continental crust

International drilling efforts over the last decades into the seafloor have provided increasing evidence for the existence of an extensive deep biosphere below the seafloor. There, circulating fluids in the sub-seafloor deliver chemical compounds from which energy is produced to fuel microbial life in such deep ecosystems. Our understanding of the role of such chemolithotrophic microbes in the continental deep biosphere, however, is much more limited due to poor accessibility.

from Latest Science News -- ScienceDaily https://www.sciencedaily.com/releases/2021/07/210727171533.htm