T. Rex and the Crater of Doom the Brazos river that a tsunami has swept across the Gulf of Mexico millions of years earlier. The discovery was made thanks to a graduate student named Alan Hildebrand that notified Alvarez of the evidence of a crater on the Yucatan peninsula, which had never been published in the scientific literature by the Mexican petroleum geologists that had found it. The age of the crater needed to be determined if it was going to be a candidate for the KT boundary impact, but access to the region was limited by the crater being buried over time and the core samples
Obolon' crater Obolon' crater Obolon' crater is a diameter buried meteorite impact crater situated about southeast of Kiev in Ukraine (Poltava Oblast). The site has been drilled, which revealed the presence of shocked minerals and impact melt rock; the high chlorine content of the latter suggesting that the area was covered by shallow sea at the time of impact. One estimate puts the age at 169 ± 7 million years (Middle Jurassic). It has been suggested by Geophysicist David Rowley of the University of Chicago, working with John Spray of the University of New Brunswick and Simon Kelley of the Open University,