Overview
- Published March 19 in Science, the research documents relative motion between East Pilbara and a near-stationary South African craton about 3.48–3.5 billion years ago.
- Analysis of more than 900 oriented cores from over 100 sites shows a latitudinal shift from roughly 53° to 77° and a clockwise rotation exceeding 90° within tens of millions of years.
- Stepwise thermal demagnetization and highly sensitive magnetometry isolate primary magnetic signals, bolstering confidence in the Archean record.
- The team identifies the oldest known geomagnetic reversal at approximately 3.46 billion years, with indications that reversals were less frequent than in later Earth history.
- The findings rule out a global stagnant lid for that time yet do not discriminate among sluggish, episodic, or modern active-lid regimes, and the paleolatitudes inform studies of early life and early crustal recycling.