title: Fission-track dating of haughton astrobleme and included biota, devon island, Canada.
abstract: Haughton Astrobleme is a major extraterrestrial impact structure located on Devon Island in the Canadian Arctic Archipelago, Northwest Territories. Apatite grains separated from shocked Precambrian gneiss contained in a polymict breccia from the center of the astrobleme yielded a fission-track date of 22.4 million +/- 1.4 million years before the present or early Miocene (Aquitanian). This provides a date for the impact event and an upper limit on the age of crater-filling lake sediments and a flora and vertebrate fauna occurring in them. A geologically precise date for these fossils provides an important biostratigraphic reference point for interpreting the biotic evolution of the Arctic.
authors.forename: G
authors.initials: G
authors.lastname: Omar
authors.forename: K R
authors.initials: KR
authors.lastname: Johnson
authors.forename: L J
authors.initials: LJ
authors.lastname: Hickey
authors.forename: P B
authors.initials: PB
authors.lastname: Robertson
authors.forename: M R
authors.initials: MR
authors.lastname: Dawson
authors.forename: C W
authors.initials: CW
authors.lastname: Barnosky