To unravel this geological mystery, the researchers utilized lead isotope compositions from rock samples across different periods and regions, including primitive meteorites and various Earth layers. By reconstructing the Earth's mantle evolution, they could compare it with the composition of the continents.
The analysis of these lead-zinc deposits yielded a fascinating discovery: around 3.2 billion years ago, they began to exhibit notable differences from the Earth's mantle. This critical period marked the onset of plate tectonics, a geological process that continues to shape our planet today. Dr. Hugo Olierook, another co-author of the study, highlighted the significance of plate tectonics in relation to Earth's ability to support life. Earth is the only planet known to have plate tectonics, and this study suggests that the development of this process may be closely linked to the planet's capacity to host life.Beyond its implications for understanding the Earth's geological history, this research also has practical applications.