Geologic Epoch

An epoch is the second smallest geochronologic unit in the geologic time scale. The cited article, Geologic time scale, which also defines the other three ranks because their own titles redirect to it, says there are 37 defined epochs and one informal one, and that the current epoch is the Holocene. It also reports that the Anthropocene was proposed as an epoch, first suggested in 2000, and that the proposal was rejected as a formal geologic epoch in early 2024, the term being left instead as an invaluable descriptor of human impact on the Earth system. Time units of this rank in the atlas are grouped under this entry.