At https://phys.org/news/2023-05-antarctic-dry-valleys-havent.html … the high elevation McMurdo dry valleys of interior Antarctica – this time, the bigger part of Antarctica, the actual coninental chunk and not the appendage, or peninsular, that was once connected to South America, is an arid and inhospitable environment. Yet, they were once warm enough to support liverworts, mosses, and shrubby trees, back in the Miocene. Beryllium 10 analysis of material extracted from bore holes showed cooling began in the Middle Pliocene – around 15 million years ago. Plant life disappeared entirely around a million years later [on the uniformitarian geochronology]. The Miocene is divided into 3 parts and perhaps represents three separate environmental events, the causes unknown but perhaps involving small movements at the poles. Hence, the fall into cool conditions – and eventually into Antarctic conditions. However, the bore holes have produced eidence that water was still a periodic factor in the McMurdos right up to the Late Miocene [which went on to last until around 5.3 million years ago]. The valleys display evidence of interwals of warm and wet climate as well as periodic dry polar aridity, through the Middle Miocene.