Convective isolation of Hadean mantle reservoirs through Archean time
Abstract
Geological processes like mantle convection or plate tectonics are an essential factor controlling Earth's habitability. Our study provides insights into timescales of convective homogenization of Earth's early mantle, employing the novel tool of high-precision 182W isotope measurements to rocks from the Pilbara Craton in Australia, that span an age range from 3.5 billion years to 2.7 billion years. Previous 182W studies mostly covered snapshots through geologic time, so the long-term 182W evolution of the mantle has been ambiguous. Together with sophisticated trace element approaches, we can now provide an improved insight into such timescales, arguing for local preservation of primordial geochemical heterogeneities within Earth's mantle as late as around 3.0 billion years, the putative onset of widespread plate tectonics on Earth.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- January 2021
- DOI:
- 10.1073/pnas.2012626118
- Bibcode:
- 2021PNAS..11812626T