60 million years of glaciation in the Transantarctic Mountains

The Antarctic continent reached its current polar location similar to 83 Ma and became shrouded by ice sheets similar to 34 Ma, coincident with dramatic global cooling at the Eocene-Oligocene boundary. However, it is not known whether the first Antarctic glaciers formed immediately prior to this or were present significantly earlier. Here we show that mountain glaciers were likely present in the Transantarctic Mountains during the Late Palaeocene (similar to 60-56 Ma) and middle Eocene (similar to 48-40 Ma). Temperate (warm-based) glaciers were prevalent during the Late Eocene (similar to 40-34 Ma) and, in reduced numbers, during the Oligocene (similar to 34-23 Ma), before larger, likely cold-based, ice masses (including ice sheets) dominated. Some temperate mountain glaciers were present during the Miocene Climatic Optimum (similar to 15 Ma), before a widespread switch to cold-based glaciation. Our findings highlight the longevity of glaciation in Antarctica and suggest that glaciers were present even during the Early-Cenozoic greenhouse world.

Automated summary

Based on our research on the formation history of Antarctic glaciers, we found that Antarctica was covered by ice sheets around 83 million years ago, and the formation of glaciers may have occurred even earlier. Different types of glaciers, including temperate and cold-based ones, have existed in Antarctica for millions of years. These findings highlight the long history of glaciation in Antarctica and suggest the presence of glaciers even during the Early-Cenozoic greenhouse world.