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
Impact crater As well as being heated, the target near the impact is accelerated by the shock wave, and it continues moving away from the impact behind the decaying shock wave. Contact, compression, decompression, and the passage of the shock wave all occur within a few tenths of a second for a large impact. The subsequent excavation of the crater occurs more slowly, and during this stage the flow of material is largely subsonic. During excavation, the crater grows as the accelerated target material moves away from the point of impact. The target's motion is initially downwards and outwards, but it becomes