A forest fire and soil erosion event during the Late Devonian mass extinction

Abstract

The Late Devonian mass extinction occurred in a stepwise manner and culminated close to the Frasnian–Famennian (F–F) boundary (372million years ago). Organic-molecular indices from marine sedimentary rocks at the Sinsin section, Belgium, indicate that the sequence of combustion of land vegetation, soil erosion, and anoxia–euxinia occurred close to this boundary. The increased concentrations of biomarkers indicating forest fire and soil erosion measured in the Sinsin section suggest that fire became widespread at this time, leading to various damaging consequences (increased runoff and oceanic anoxia) that caused marine extinctions. Magnetic susceptibility data in the Sinsin section indicate a relatively dry climate spanning the F–F boundary, which would have encouraged forest fires. The study of organic biomarkers presents several lines of evidence to link forest fire and soil erosion to the Late Devonian mass extinction.