Novel Be-10 and extraterrestrial He-3 depth profile in old, buried glacier ice of Mullins Glacier, upper Beacon Valley, Antarctica.

Dating of surrounding sediments and volcanic ashes indicates that these ice bodies may be up to six million years in age, offering the oldest direct atmospheric and climate records available. This work is a proof of concept to develop a new dating technique using beryllium (10Be) of cosmogenic origin from the atmosphere and extraterrestrial helium (3He) contained in interplanetary dust particles.

Both tracers are deposited to the Earth's surface and likely incorporated into the ice matrix at constant rates. Radioactive decay of 10Be versus the stable extraterrestrial 3He signal may offer way to directly measure the age of the ice. The broader impacts of this work are development of a new analytical technique that may improve society's understanding of the potential for global climate change from the perspective of the deep time record.