Scientists have two main hypotheses to explain this unusual accumulation of 10Be:

Alterations in ocean currents: It is known that between 10 and 12 million years ago the currents near Antarctica underwent drastic changes. This could have affected the distribution of beryllium-10 on the planet, concentrating it especially in the Pacific Ocean.

An astrophysical event: Another possibility is that a nearby supernova temporarily increased the cosmic radiation reaching Earth. Also considered is the possibility that our planet passed through a dense interstellar cloud that weakened the protection of the heliosphere, allowing an increase in cosmic radiation.