The earliest evidence for modern-style plate tectonics recorded by HP-LT metamorphism in the Paleoproterozoic of the Democratic Republic of the Congo.

ABSTRACT: Knowing which geodynamic regimes characterised the early Earth is a fundamental question. This implies to determine when and how modern plate tectonics began. Today, the tectonic regime is dominated by mobile-lid tectonics including deep and cold subduction. However, in the early Earth (4.5 to 2 Ga) stagnant-lid tectonics may also have occurred. The study of high pressure-low temperature (HP-LT) metamorphic rocks is important, because these rocks are only produced in present-day subduction settings. Here, we characterize the oldest known HP-LT eclogite worldwide (2089 ± 13 Ma; 17-23 kbar/500-550 °C), discovered in the Democratic Republic of the Congo. We provide evidence that the mafic protolith of the eclogite formed at 2216 ± 26 Ma in a rift-type basin, and was then subducted to mantle d

SUBMITTER: Francois C 

PROVIDER: S-EPMC6193989 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature