Paleomagnetic detection of relative plate motions and an infrequently reversing core dynamo at 3.5 Ga

• 成果类型: Article
• 署名作者: Brenner, Alec R.; Fu, Roger R.; Foley, Bradford J.; Lourenco, Diogo L.; Palma-Gomez, Jasmine; Gong, Zheng; Steele, Sarah C.; Li, Joanna; Flannery, David T.; Brown, Adrian J.; Hodgin, Eben B.
• 署名单位: Harvard University; Yale University; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Swiss Federal Institutes of Technology Domain; ETH Zurich; Smith College; Rice University; Queensland University of Technology (QUT); Brown University
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-8075; 1095-9203
• DOI: 10.1126/science.adw9250
• 发表日期: 2026-03-19
• 页码: 1278-1282
• 关键词: barberton greenstone-belt; GEOMAGNETIC SECULAR VARIATION; MARBLE-BAR-CHERT; NORTH-POLE DOME; pilbara craton; SOUTH-AFRICA; DEPENDENT VISCOSITY; western-australia; KOMATI FORMATION; ARCHEAN TECTONICS

摘要

Whether early Earth had a mobile lithosphere and plate tectonics is debated. We present paleomagnetic data quantifying differential motion between lithospheric blocks at similar to 3.48 billion years ago (Ga). This manifested as 47(-35)(+69) centimeters per year latitudinal motion of the East Pilbara Craton (Western Australia) across high latitudes, whereas the Barberton Greenstone Belt (South Africa) was stationary at low latitudes. Comparison of this plate motion with candidate analogs suggests either rapid collisional plate tectonics (i.e., an active-lid) or an episodically mobile lithosphere. We also document the oldest known geomagnetic reversal at similar to 3.46 Ga, consistent with an axial dipolar dynamo that reversed less frequently than today's. The existence and rates of these surface and core geophysical phenomena provide geodynamic context to Earth's early geophysical and biological evolution.