Rocks once buried deep in ancient subduction zones — where tectonic plates collide — could help scientists make better predictions of how these zones behave during the years between major earthquakes, according to a research team from Penn State and Brown University.
Rocks once buried deep in ancient subduction zones — where tectonic plates collide — could help scientists make better predictions of how these zones behave during the years between major earthquakes, according to a research team from Penn State and Brown University.
Clues from rock formations in Alaska and Japan allowed the scientists to develop a new model to predict the pressure solution activity in subduction zones, the researchers reported in the journal Science Advances. Sedimentary rocks comprise grains surrounded by water-containing pores. When rocks are squeezed together under great pressure, the grains dissolve at their boundaries into the water present in pores, forming pressure solution. This allows the rocks to deform, or change shape, influencing how the tectonic plates slide past each other.
“It’s like when you go ice skating — the blade on the surface ends up melting the ice, which allows you to glide along,” said corresponding author Donald Fisher, professor of geosciences at Penn State. “In rocks, what happens is quartz grains dissolve at stressed contacts and the dissolved material moves to cracks where it precipitates.”
Read more at: Penn State
Photo Credit: Donald Fisher
