Zealandia, an underwater landmass, once part of the ancient supercontinent Gondwana, has been a geological mystery due to its submerged state. Recent research, utilizing geochemical data, isotope analysis, and seismic readings, has shed light on its origins. Zealandia’s crust experienced subduction nearly 250 million years ago, pushing it beneath Earth’s mantle. Contrary to prior beliefs, magnetic anomalies in the region are unrelated to this event. Instead, they likely resulted from the stretching and separation of Gondwana, allowing Zealandia to break away. The study suggests that Zealandia’s crust underwent significant thinning before detachment, providing valuable insights into Earth’s geological history.
Source: https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2023TC007961