Anomalous Cold in the Pangaean Tropics?
How cold were the late Paleozoic tropics? We have uncovered a growing body of evidence for upland glaciation in western equatorial Pangaea—specifically, within large paleo-highlands of the Ancestral Rocky Mountains. This is some of the first evidence for Permo-Pennsylvanian glaciation outside of the southern polar region, and is highly controversial. The tropical setting poses a conundrum: were the mountains really that high, or was the global climate –at times– that cool? Moreover, part of our evidence is discovery of a modern landform of the Rocky Mountains, hypothesized to date from 300 My ago, and to have been carved glacially. The remarkable age of this landscape poses a tectonic paradox: how does one preserve a valley within an actively eroding uplift? In addition to standard field studies, we are undertaking drilling and geophysical studies to assess the paleo-landscape hypothesis. We are also examining the possibility of near-glacial conditions in other highland-proximal systems of the Ancestral Rocky Mountains, as well as long-hypothesized claims of glaciation in the paleo-uplands of eastern equatorial Pangaea (now present-day France).