CANBERRA, Feb. 10 (Xinhua) -- The discovery of Beryllium-10, a rare radioactive isotope produced by cosmic rays in the atmosphere, provides valuable insights into the Earth's geological history, and has the potential to be an independent time marker for marine archives.
Australian and German scientists discovered an "unexpected" accumulation of the isotope in samples taken from the bottom of the Pacific Ocean, which can unlock the secrets of Earth's evolutionary past, according to the study published in the scientific journal Nature Communications on Monday.
Such an anomaly may be attributed to shifts in ocean currents or astrophysical events that occurred approximately 10 million years ago, the study said, adding that the findings hold the potential to serve as a global time marker, representing a promising advancement in the dating of geological archives spanning millions of years.
The floor of the major oceans on Earth exhibits one of the most pristine geological archives recording millions of years of environmental conditions and changes, it said.
"For periods spanning millions of years, such cosmogenic time markers do not yet exist. However, this beryllium anomaly has the potential to serve as such a marker," said the study's lead author Dominik Koll from the Australian National University (ANU).
Radionuclides are types of atomic nuclei, or isotopes, that decay into other elements over time. They are used to date archaeological and geological samples, with radiocarbon dating being one of the most well-known methods, the study showed.
The research team comprises scientists from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), a research laboratory in Germany, the TUD Dresden University of Technology in Germany and the ANU. ■
