Though old rocks hold on to their secrets, a geophysicist has unlocked clues trapped in the magnetic signatures of mineral grains in those rocks.
These clues from the study led by Michigan Technological University's Aleksey Smirnov will help clear up the murky history of the Earth's early core.
The work took him Down Under, where he drilled into rock outcrops in Australia's Widgiemooltha dike swarm that are more than two billion years old.
Studying rocks this old and extracting data from them is tricky but helps unravel the core's mysteries.
However, Smirnov's findings created their own mystery: the magnetic readings were significantly larger than anticipated.
This could have implications for early life on earth.
The study appears in the journal Earth and Planetary Science Letters.
