What is it about?
We track the composition of the upper continental crust by analyzing the fine-grained sediment within glacial tills that were deposited over the past 3 billion years. For this, we use a relatively new proxy -- stable vanadium isotopes.
Photo by Jim Petkiewicz on Unsplash
Why is it important?
We find a dramatic shift in the average composition of the upper crust in the late Archean (3-2.5 billion years ago), with Archean crust dominated by more mafic (e.g., basaltic) rock types. This could mark the onset of plate tectonics in the late Archean.
Read the Original
This page is a summary of: Dominance of felsic continental crust on Earth after 3 billion years ago is recorded by vanadium isotopes, Proceedings of the National Academy of Sciences, March 2023, Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.2220563120.
You can read the full text:
The following have contributed to this page