Matuyama A reversed polarity chron at the end of the Pliocene and the beginning of the Pleistocene. It is preceded by the Gauss and followed by the Brunhes normal-polarity chrons, and is radiometrically dated as occurring between 2.60 and 0.78 Ma. The Matuyama contains at least three normal polarity subchrons: Réunion, Olduvai, and Jaramillo.

Matuyama The penultimate chron; during most of it the prevailing magnetization was reversed (i.e. the magnetic north and south poles were reversed from their present orientation). It lasted, with a few subchrons of normal polarity, from 2.4 to 0.71 Ma ago.