Basal section of the Beyond EPICA Little Dome C ice core

The Beyond EPICA project aims to collect ice of more than one million years of age. This ice is found approx. 200m above bedrock, the basal unit remained a mystery before drilling. We present the first results from the basal unit, i.e. the section identified from radio-stratigraphy, which seemed to be unstratified and, based on modeling results, also potentially stagnant. Variations in crystal size measured on-site reveal the gradual transition into this basal unit. In the approx. 5 m of basal ice recovered from the core, we find layered bands containing 1-2mm rocks, clogged clays sections of banded dispersed facies, and repetitive transitions of clear ice to debris-rich ice. The mineralogic composition is mainly of granitic and gneiss rocks, mainly in the size fraction of sand. With these new results, we can increase our understanding of ice sheets' formation and evolution, ice flow over the bedrock, and variations in rheology due to ice crystals.