Global cooling initiated stony deserts in central Australia 2-4 Ma, dated by cosmogenic 21Ne-10Be.

Stony deserts are durable indicators of aridity but until now have not been directly dated. Using 21Ne and 10Be produced in surface rocks by cosmic rays, we show that Australian stony deserts formed 2-4 Ma, at the time when global cooling initiated the Quaternary ice ages and intensified aridity-induced major landscape changes in central Australia. This is the first direct determination of stony desert ages, using a new method for determining cosmogenic 21Ne in the presence of various neon components from other sources. [ABSTRACT FROM AUTHOR]