The Brunhes-Matuyama reversal
The magnetic field flips for the last time, and the compass has pointed the same way ever since.
- When
- —
- Duration
- 11 thousand years
- Known to
- ± 6 thousand years
- Era
- Early Pleistocene, Quaternary
Between about 784,000 and 773,000 years ago the geomagnetic field reverses from the Matuyama reversed chron to the Brunhes normal chron — the most recent full polarity reversal. The transition takes several thousand years, during which field strength drops sharply and the poles wander. It is the single most widely used datum in Quaternary stratigraphy, recorded in ocean sediments, lava flows, loess and cave deposits worldwide, and it defines the boundary between the Early and Middle Pleistocene.