REVISED AGE FOR THE GOSSES BLUFF IMPACT STRUCTURE, NORTHERN TERRITORY, AUSTRALIA, BASED ON ⁴⁰Ar/³⁹Ar DATING

40 Ar/ 39 Ar dating of a pumiceous suevite clast from the melt breccia at Gosses Bluff consisting largely of extremely fine‐grained sanidine yields a discordant age spectrum, probably reflecting some diffusional loss of argon. High‐temperature increments that together yield a near‐plateau age of 142.5 Ma are apparently not affected by argon loss and offer the best estimate of the date of the Gosses Bluff event. The event may fall in the latest Jurassic Period, but more likely falls in the earliest Cretaceous, probably in one of the reverse‐polarity magnetochrons M16, M17, or M18.