Thomas Gold was a scientific jack of all trades being involved in physics, cosmology and geochemistry, the latter of interest to us here. He thought petroleum and other hydrocarbons were actually produced by micro-organisms below the surface of the earth, providing us with a replenishable supply (how ecological !) Here’s part of a Wiki article about him — Hydrocarbons are not biology reworked by geology (as the traditional view would hold), but rather geology reworked by biology.– https://en.wikipedia.org/wiki/Thomas_Gold.
Why bring him up now? Because [ Proc. Natl. Acad. Sci. vol. 115 pp. 10702 – 10707 ’18 ] (http://www.pnas.org/content/115/42/10702) showed that 600 meters below the surface (where light and molecular oxygen never go) Cyanobacteria were found. They use the electrons stripped from hydrogen (which is said to be produced in the subsurface by several (unspecified) abiotic mechanisms) as an energy source. The electrons have to go somewhere, and they postulate that the electron acceptors are iron or manganese oxides. Wherever microorganisms have been found in deep continental settings hydrogen concentration decreases.
Basically life acts as the middleman, taking an energy cut from the flow of electrons from reductant to oxidant.
Seriously, life may have actually arisen in such situations.
Chemiotics II 
Comments
serpentinization can produce hydrogen from certain rocks. It is the likely source of methane seeps on Mars as well. An environment where that is happening would likely be rich in minerals / nutrients, though I’m not sure about nitrogen.