There is the big news, at least as considered by its authors.
There is the big news, at least as considered by its authors.
It's the same nonsense we demolished about two months ago. It's based on the unfounded assumption that helium diffuses easily in zircons. It doesn't. A recent paper found a activation energy for helium diffusion of 44 kcal/mol., and a closure temperature of 190 C. (The closure temperature is the temperature below which diffusion is negligible). A zircon which has not been exposed to temperatures above 190C should retain its helium.
He diffusion and (U-Th)/He thermochronometry of zircon: initial results from Fish Canyon Tuff and Gold Butte. Reiners, Peter W.; Farley, Kenneth A.; Hickes, Hunter J. Department of Geology, Washington State University, Pullman, WA, USA. Tectonophysics (2002), 349(1-4), 297-308.