Chicxulub Crater: A possible Cretaceous/Tertiary boundary impact crater on the Yucatán Peninsula, Mexico.

Eleven years after publication of No. 14207, Alan Hildebrand, working with Luis and Walter Alvarez, proposed that the Chicxulub Crater, discovered by Antonio-Camargo-Zanoguera and Glen T. Penfield during the 1970s, was the C-T boundary impact crater posited in No. 14207.

"ABSTRACT: We suggest that a buried 180-km-diameter circular structure on the Yucatan Peninsula, Mexico, is an impact crater. Its size and shape are revealed by magnetic and gravity-field anomalies, as well as by oil wells drilled inside and near the structure. The stratigraphy of the crater includes a sequence of andesitic igneous rocks and glass interbedded with, and overlain by, breccias that contain evidence of shock metamorphism. The andesitic rocks have chemical and isotopic compositions similar to those of tektites found in Cretaceous/Tertiary (K/T) ejecta. A 90-m-thick K/T boundary breccia, also containing evidence of shock metamorphism, is present 50 km outside the crater's edge. This breccia probably represents the crater's ejecta blanket. The age of the crater is not precisely known, but a K/T boundary age is indicated. Because the crater is in a thick carbonate sequence, shock-produced CO 2 from the impact may have caused a severe greenhouse warming."

Order of authorship in the original publication: Hildebrand, Penfield, Kring...Camargo et al.

(Thanks to Juan Weiss for this reference and its interpretation.)