We just came across this 9 Dec 2019 beautifully illustrated review of the work of the Deep Carbon Observatory, especially its work on the deep biosphere, a subject in which Russian and Ukrainian scientists have made important contributions since Mendeleev. Jesse Ausubel is quoted near the end of the article.
How they live where almost nobody lives: the dark side of the biosphere Life exists at a depth of several kilometers, in the hot and oxygen-deprived bowels of the Earth – and thrives there, completely uninterested in anything that happens here, above.