Project summary

MEET stands for Monitoring Earth Evolution through Time.

The main goal of the MEET project is to investigate the Earth’s evolution since its creation, over 4.5 billion years ago. The three principal investigators are Alexander Sobolev (Université Grenoble Alpes, France), Stephen Sobolev (GFZ Potsdam, Germany), and John Valley (University of Wisconsin- Madison, USA).

This project will investigate two main questions: How has Earth’s chemical composition evolved over time? And what physical processes are responsible for these changes?

Previous attempts to understand the early Earth have been stymied because rocks that are archives from this time are either destroyed or altered so that the original chemical information is gone. However, there is a unique possibility to retrieve the chemical tracers most sensitive to changes of Earth’s mantle and crust. This information is preserved in the composition of melt inclusions in crystals of minerals olivine and zircon. (Figure 1)

These are tiny drops of melt that were trapped when the mineral crystallized. They typically measure less than 15 microns and weigh just a few nanograms. Unique microanalytical equipment for in-situ chemical analysis of such inclusions has been installed in the Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA) and, in conjunction with other in situ techniques such as Secondary Ion Mass Spectrometry (SIMS) at UW-Madison, deliver new information on the recycling of chemical elements in the Earth and on formation of its crust from about 4.4 billion years ago to present day. The evolution of Earth has profound implications for questions in other disciplines, such as the origin of life and the conditions on exoplanets.

Updated on 22 March 2023