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Titre	The age of the Popigai impact event and its relation to events at the Eocene/Oligocene boundary
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Auteur	Bottomley, R; Grieve, R; York, D; Masaitis, V
Source	Nature vol. 388, 1997 p. 365-368, https://doi.org/10.1038/41073 Accès ouvert
Année	1997
Séries alt.	Commission géologique du Canada, Contributions aux publications extérieures 1996430
Éditeur	Springer Nature
Document	publication en série
Lang.	anglais
DOI	https://doi.org/10.1038/41073
Media	papier; en ligne; numérique
Formats	pdf
Région	Popigai
Lat/Long OENS	110.9167 111.0833 71.5833 71.4167
Sujets	Oligocène; Eocene; datation argon-argon; Pliocène; cratères météoriques; datation radiométrique; Structure d'impact de Popigai ; Bouclier d'Anabar; géologie extraterrestre; stratigraphie; géochronologie; Crétacé; Tertiaire
Illustrations	spectres
Diffusé	1997 07 24
Résumé	(disponible en anglais seulement) Ages ranging from the Late Cretaceous (~65 Myr) to the Oligocene (~29 Myr) have been reported for the 100-km-diameter Popigai impact structure on the Anabar shield, central Siberia. These ages overlap the timing of several possible impact-related features, including the Cretaceous/Tertiary and Eocene/Oligocene stratigraphic boundaries, the North American tektites, and the recently reported occurrences of an iridium anomaly and shocked quartz in Late Eocene deposits in northern Italy. Here we report age determinations of several Popigai impact melt rocks using the 40Ar-39Ar step heating technique to constrain the age of the impact event. Our results are consistent with a Late Eocene impact age of 35.7± 0.2 Myr (2s)-coincident in time with the impact deposits found in Italy. As this age is also similar to that of the North American tektites, which have been associated with the Chesapeake Bay impact structure in the eastern United States there seem to have been at least two large and essentially contemporaneous impacts during the Late Eocene.
GEOSCAN ID	208344