SYDNEY, Jan. 14 (Xinhua) -- Researchers unveil a new "cosmic clock" method to unlock Australia's ancient landscape history, revealing geological, climate and tectonic impacts on environments, and valuable mineral deposits.
Scientists from Curtin University's Timescales of Mineral Systems Group in Australia, working with Germany's University of Gottingen and University of Cologne, analyzed tiny zircon crystals found in ancient beach sands, said a news release from Curtin University on Wednesday.
Zircon, one of Earth's toughest minerals, withstands weathering, erosion and multi-million-year journeys through rivers and coastlines, the release said, adding zircon grains trap rare krypton gas produced when cosmic rays -- high-energy, charged subatomic particles from space -- strike exposed minerals at Earth's surface.
By measuring the krypton, the team was able to work out how long zircon grains spent near the Earth's surface before burial, like a "cosmic clock" tracking ancient landscape erosion over vast periods of time, it said.
This approach enables study of landscapes far older than previously possible, revealing how Earth's surface responds to ongoing climate and tectonic change, said study lead author, Adjunct Curtin Research Fellow Maximilian Drollner, also from the University of Gottingen.
"Our planet's history shows climate and tectonic forces can control how landscapes behave over very long timescales," Drollner said, adding the research shows how sea-level changes and deep-seated Earth movements influence the evolution of landscapes.
The findings, published in Proceedings of the National Academy of Sciences (PNAS), show when landscapes are tectonically stable and sea levels remain high, erosion slows dramatically and sediments can remain stored and reworked near the surface for millions of years.
This has relevance for understanding planetary surface evolution over billions of years, plus future societal planning and land management, said co-author, Curtin's Timescales of Mineral Systems Group lead Professor Chris Kirkland.
The study also had important implications for Australia's mineral resources, "explaining why Australia hosts some of the world's most significant mineral sand deposits," the authors said. ■