Earth’s crust melts easier: Study

Geologists have revealed that the Earth’s crust melts easier than previously thought, a key finding which they claim will provide insight into how magmas are formed and lead to better models of continental collision.

Geologists have revealed that the Earth's crust melts easier than previously thought, a key finding which they claim will provide insight into how magmas are formed and lead to better models of continental collision.

In its study, a team at the University of Missouri has measured how well rocks conduct heat at different temperatures and found that as rocks get hotter in the Earth's crust, they become better insulators and poorer conductors.

Prof Alan Whittington, who led the team, said: "In the presence of external heat sources, rocks will heat up more efficiently than previously thought.

"We applied our findings to computer models that predict what happens to rocks when they get buried and heat up in mountain belts, such as the Himalayas today or the Black Hills in South Dakota in the geologic past.

"We found that strain heating, caused by tectonic movements during mountain belt formation quite easily triggers crustal melting."

In the study, the geologists used a laser-based method to determine how long it took heat to conduct through various rock samples. In all of them, thermal diffusivity, or how well a material actually conducts heat, clearly decreased rapidly with increasing temperatures.