subepoch

Subepoch refers to a division of a larger geological epoch. Epochs are the smallest official units of the geologic time scale, subdividing periods. When an epoch is further divided for finer chronological resolution, these smaller divisions are termed subepochs. For instance, the Pleistocene Epoch is often divided into the Early Pleistocene, Middle Pleistocene, and Late Pleistocene subepochs. These subdivisions are not always formally recognized by the International Commission on Stratigraphy (ICS), which is the ultimate authority on the geologic time scale, but are commonly used in scientific literature and in regional geological studies. The boundaries of subepochs are typically defined by specific fossil assemblages or radiometric dates that mark significant changes in the geological or biological record. The use of subepochs allows for a more detailed examination of events and environmental changes within a particular epoch.