The trunk of an ancient kauri tree from Ngāwhā, Northland. This dramatic turning point in Earth's history was triggered by a reversal of Earth's magnetic poles and changing solar winds. Sequential blocks of wood consisting of 40 annual rings were extracted from four ancient kauri logs and dated by a process called high-precision liquid scintillation counting. These findings come two years after a particularly important ancient kauri tree was uncovered at Ngāwhā, Northland. This new ancient kauri timescale has helped to reveal what happened during a dramatic period in Earth's history.

Source: New Zealand Herald February 18, 2021 21:00 UTC