Matuyama

Matuyama is a geologic polarity interval in Earth’s geomagnetic history, defined by a predominantly reversed magnetic polarity during a span of the Cenozoic era. It forms a major backward (reverse) interval on the geomagnetic polarity timescale and is used to anchor correlations between marine and continental sequences.

In the standard timescale, the Matuyama Chron extends from about 2.58 million years ago to about 0.781 million years ago. It is preceded by the Gauss Chron, which contains intervals of normal polarity, and it is followed by the Brunhes Chron, marked by normal polarity. The boundary between Matuyama and Brunhes, the Brunhes–Matuyama boundary, is a widely used marker for dating sediments and volcanic rocks, especially in paleomagnetic and stratigraphic studies.

Rocks that record Matuyama polarity are found in many regions around the world, including marine sediments and terrestrial sequences. Identifying the Matuyama reversal in a section helps establish a temporal framework for associated climatic, tectonic, or faunal records, and it provides a basis for correlating events across distant regions when combined with other stratigraphic and radiometric data.

The term Matuyama is part of the broader discipline of paleomagnetism and the geomagnetic polarity timescale, which track changes in Earth’s magnetic field through time. It is commonly referenced in geology, paleontology, and climate research to date geological formations and to interpret past geophysical and environmental conditions.

See also: Brunhes Chron, Gauss Chron, Geomagnetic polarity timescale, Paleomagnetism.