Researchers extracted cores from the Chicxulub crater recently – see www.livescience.com/56914-dino-killing-asteroid-may-have-punctured-earth… … It measures 110 miles across (180km) and is situated in Mexico's Yucatan peninsular. An object 6 miles across is thought to have crashed into the Earth – and brought the dinosaur age to a close. The research was focused on taking samples from the peak ring (under 50 feet of water). Holes were drilled into the sea floor to as far as 4380 feet deep. They discovered granite which had welled up towards the surface on impact, due to a shock wave. The impact hole may have been as deep as 18 miles – puncturing the crust. Flow would immediately follow in order to fill in the hole – but outward movement created the peak ring (a chain of mountains surrounding the crater). At the same time the centre of the hole reached upwards, like throwing a stone into the pond (and a water droplet rising in the aftermath), rising up before collapsing back down again. The end result, geologically, is a ring of high ground (the peak ring).
At https://phys.org/print429505416.html … another article in the journal Science (Nov 17th 2017) shows sudden warming at the end of the Ice Age caused the Cordillera ice sheet to melt rapidly (in a period of up to 500 years). This explains why the ice sheet did not re-emerge during the Younger Dryas episode, when temperatures plunged again, as the ice had completely gone. The CAGW obligatory bit claims the current Greenland ice sheet may disappear just as quickly – as a result of modern warming. This ignores the catastrophic implications of the Late Pleistocene changes.