Rock meets microbe: Towards better models of subsurface microbial communities

Beneath the land are subsurface aquifers in which deposits of gravels, sands, silts, and clays mix with water and microbial communities. These subsurface gatherings of microbes, metabolically influenced by the mineral mixes that bind them, are busy with the business of microscopic life: eating carbon and excreting gases, which in turn (by virtue of microbial abundance) greatly influence the composition of the Earth's atmosphere.