Reports

Microtektites and Mass Extinctions: Evidence for a Late Devonian Asteroid Impact

See allHide authors and affiliations

Science  21 Aug 1992:
Vol. 257, Issue 5073, pp. 1102-1104
DOI: 10.1126/science.257.5073.1102

Abstract

Glass spherules, similar to microtektites, have been found near the Frasnian-Famennian boundary (F/F) (Upper Devonian) at Senzeilles, Belgium, contemporaneous with one of the largest marine mass extinctions of the Phanerozoic. These spherules exhibit a wide range of compositions and display teardrop, dumbbell, and compound morphologies analogous to microtektites. In addition, they lack crystallites, have few or no vesicles, and have a low content of volatile material. These characteristics are supportive of an impact origin. The Siljan Ring (Sweden) and Charlevoix structure (Quebec,Canada) are candidate craters of this age. The presence of microtektites near the F/F boundary supports the hypothesis that an impact caused the Upper Devonian worldwide benthic mass extinctions.