Title

Impact ejecta layer from the mid-Devonian: Possible connection to global mass extinctions

Document Type

Article

Publication Date

6-13-2003

Abstract

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)

Science

First Page

1734

Last Page

1737

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