Earth's crust melts easier than previously thought

A University of Missouri study published in Nature this week has found that the Earth's crust melts easier than previously thought.

In the study, researchers 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. This finding provides insight into how magmas are formed and will lead to better models of continental collision and the formation of mountain belts.

“In the presence of external heat sources, rocks will heat up more efficiently than previously thought,” said Alan Whittington, professor of geological sciences in the MU College of Arts and Science. “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, researchers used a laser-based technique to determine how long it took heat to conduct through different rock samples. In all of the samples, thermal diffusivity, or how well a material conducts heat, decreased rapidly with increasing temperatures. Researchers found the thermal diffusivity of hot rocks and magmas to be half that of what had been previously assumed.

“Most crustal melting on the Earth comes from intrusions of hot basaltic magma from the Earth's mantle,” said Peter Nabelek, professor of geological sciences in the MU College of Arts and Science. “The problem is that during continental collisions, we don't see intrusions of basaltic magma into continental crust. These experiments suggest that because of low thermal diffusivity, strain heating is much faster and more efficient, and once rocks get heated, they stay hotter for much longer. Of course, these processes take millions of years to occur and we can only simulate them on a computer. This new data will allow us to create computer models that more accurately represent processes that occur during continental collisions.”

The study, “Temperature-dependent thermal diffusivity of the Earth's crust and implications for magmatism,” was published in this week's Nature and was co-authored by Whittington, Nabelek and Anne Hofmeister, a professor at Washington University. The National Science Foundation funded this research.

Media Contact

Kelsey Jackson EurekAlert!

More Information:

http://www.missouri.edu

All latest news from the category: Earth Sciences

Earth Sciences (also referred to as Geosciences), which deals with basic issues surrounding our planet, plays a vital role in the area of energy and raw materials supply.

Earth Sciences comprises subjects such as geology, geography, geological informatics, paleontology, mineralogy, petrography, crystallography, geophysics, geodesy, glaciology, cartography, photogrammetry, meteorology and seismology, early-warning systems, earthquake research and polar research.

Back to home

Comments (0)

Write a comment

Newest articles

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Memory Self-Test via Smartphone

… Can Identify Early Signs of Alzheimer’s disease. Dedicated memory tests on smartphones enable the detection of “mild cognitive impairment”, a condition that may indicate Alzheimer’s disease, with high accuracy….

Partners & Sponsors