New laser tool reveals helium secrets
Curtin University researchers have for the first time been able to visualise where helium atoms are trapped within individual mineral grains, providing information that can help to determine the geological history of the Earth’s crust and assist in monitoring natural hazards like earthquakes and volcanic eruptions.
“We then used numerical simulations to determine how thermal events in the Earth’s crust influenced helium abundance patterns in the crystal over geological time,” Dr Danišík said.
Professor McInnes, who conceived the instrument concept and assembled the project team, said the ability to measure radiogenic helium distributions in individual grains could help scientists understand more about the timing of fault movement, volcanic eruptions and mountain building processes, as well as assist in the exploration for mineral and petroleum deposits.
“We were surprised to discover extremely high concentrations of helium in cavities within crystals, and speculate that this could be useful in earthquake monitoring, because the crushing of minerals during fault motion should break open these cavities and release a flux of helium gas that can be detected at surface,”
“Our team has previously demonstrated that minerals in diamond-bearing kimberlite pipes have uniquely low abundances of helium, and this technology can be used to rapidly scan exploration samples to both detect kimberlitic zircon and identify the age of the kimberlite pipe.”
Dr Bruce Godfrey, CEO of ASI Pty Ltd, said the company was pleased to collaborate with Curtin in the development of this innovative geochemical technique.
“We look forward to developing the instrument platform for the international market,” Dr Godfrey said.
A paper detailing the findings, Seeing is believing: Visualization of He distribution in zircon and implications for thermal history reconstruction on single crystals, was published recently in Science Advances.
A video explaining the findings can be found here.