Archean Asteroid Impacts on Earth: Stratigraphic and Isotopic Age Correlations and Environmental Consequences
It is generally agreed that the Archean Earth was subject to a higher impact flux then on the present day Earth, however the rate and influence of large impacts on early Earth environments is still poorly understand. Here we present an overview of the evidence from the rock record for early impacts using the best-studied sequences containing impact layers in the Kaapvaal and Pilbara cratons, ranging in age from 3.47 to 2.49 Ga. A summary of correlations of individual spherule deposits is presented from within and between the two cratons using stratigraphy, petrography, zircon geochronology, platinum-group element (PGE) and Cr isotope geochemistry, and shocked mineralogy. We then evaluate the results of several studies that have suggested environmental and tectonic consequences of the impacts as predicted by impact modeling and discuss outstanding questions.
Davatzes, Alexandra Krull, Steven Goderis, and Bruce M. Simonson. "Archean Asteroid Impacts on Earth: Stratigraphic and Isotopic Age Correlations and Environmental Consequences." In Earth's Oldest Rocks, edited by Martin Van Kranendonk, Vickie Bennett, and Elis Hoffmann, 169-185. Second ed. New York: Elsevier, 2018.
Martin Van Kranendonk, Vickie Bennett, Elis Hoffmann
Earth's Oldest Rocks
Archean bombardment, Impacts, Shocked minerals, Spherules