Impact ejecta layer from the mid-Devonian: Possible connection to global mass extinctions
We have found evidence for a bolide impacting Earth in the mid-Devonian (∼380 million years ago), including high concentrations of shocked quartz, Ni, Cr, As, V, and Co anomalies; a large negative carbon isotope shift (-9 per mil); and microspherules and microcrysts at Jebel Mech Irdane in the Anti Atlas desert near Rissani, Morocco. This impact is important because it is coincident with a major global extinction event (Kacák/otomari event), suggesting a possible cause-and-effect relation between the impact and the extinction. The result may represent the extinction of as many as 40% of all living marine animal genera.
Publication Source (Journal or Book title)
Ellwood, B., Benoist, S., El Hassani, A., Wheeler, C., & Crick, R. (2003). Impact ejecta layer from the mid-Devonian: Possible connection to global mass extinctions. Science, 300 (5626), 1734-1737. https://doi.org/10.1126/science.1081544