Earth's crust melts easier than we thought

A study conducted by the University of Missouri, published in Nature, found that the Earth's crust melted more easily than we thought. In the study, scientists analyzed the heat conductivity of rock and soil at different temperatures and found that rock and soil in the Earth's crust became warmer, which became poorer insulation and thermal conductors.

This finding provides new insights into how cyanobacteria form, while providing more accurate models of continental collisions and the formation of mountain belts.

Alan Whittington, professor of geological sciences at MU University of Arts and Science, said: 'With the presence of external heat sources, rock and soil will heat up more effectively than they think. We have used this discovery to build a model to predict what will happen to rock when they are buried and heated in mountain belts, like today's Himalayas or Black Hills. South Dakota in the past geological period. We found that the phenomenon of warming due to tectonic movements during the formation of the mountain belt could easily stimulate the melting of the earth's crust. '

In the study, scientists used laser technology to determine the time needed to conduct heat from different rock samples. The thermal conductivity of the samples decreases rapidly when the temperature rises. The researchers also found that the thermal conductivity of hot stones and magnesia is only half that of our previous observations.

Picture 1 of Earth's crust melts easier than we thought Mount Rushmore made from manganese-derived granite formed 1.7 billion years ago in a collision between smaller tectonic plates, which together form the central part of the Arctic continent. The reduced heat dissipation during the impact and tectonic deformation event contributed to melting the rock in the crust of the ancient mountain belt melting in a manner similar to the production of granite in the phenomenon. Himalayan continent collision. (Photo: Photo courtesy of Peter Nabelek)

Peter Nabelek, professor of geological sciences at MU University of Arts and Science, said: 'Most of the melting of the earth's crust occurs due to the invasion of molten basalt from the mantle crust. The problem is that during the continental collision, we did not see the invasion of basalt in the continental crust. The above experiments show that the main reason is low thermal conductivity, as well as faster and more efficient heating. Once the rock is heated, they will become hot for a longer time. Of course this process takes millions of years to happen, and we have only simulated it on computers. But new data has also allowed us to create more accurate computer models that show the processes that occur in continental collisions. '

Co-authors of the study include Whittington, Nabelek and Anne Hofmeister, professors at the University of Washington. The National Science Foundation funded this research.

Refer:
Temperature-dependent thermal diffusivity of the Earth's crust and implications for magmatism.Nature, March 19, 2009

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