Re-evaluating the age of the Haughton impact event

Sherlock, Sarah C.; Kelley, Simon P.; Parnell, John; Green, Paul; Lee, Pascal; Osinski, Gordon R. and Cockell, Charles S. (2005). Re-evaluating the age of the Haughton impact event. Meteoritics and Planetary Science, 40(12) pp. 1777–1787.

URL: http://www.ingentaconnect.com/content/arizona/maps...

Abstract

We have re-evaluated the published age information for the Haughton impact structure, which was believed to have formed similar to 23 Ma ago during the Miocene age, and report new Ar/Ar laser probe data from shocked basement clasts. This reveals all Eocene age, which is at odds with the published Miocene stratigraphic, apatite fission track and Ar/Ar data; we discuss our new data within this context. We have found that the age of the Haughton impact structure is similar to 39 Ma, which has implications for both crater recolonization models and post-impact hydrothermal activity. Future work on the relationship between flora and fauna within the crater, and others at high latitude, may resolve this paradox.