The University of Arizona

Re-evaluating the age of the Haughton impact event

Sarah C. Sherlock, Simon P. Kelley, John Parnell, Paul Green, Pascal Lee, Gordon R. Osinski, Charles S. Cockell


We have re-evaluated the published age information for the Haughton impact structure, which was believed to have formed ~23 Ma ago during the Miocene age, and report new Ar/Ar laser probe data from shocked basement clasts. This reveals an 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 ~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.


40Ar-39Ar dating;Eocene;Haughton impact structure;Laser probe

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