Rock Samples Indicate Water is Key Ingredient for Crust Formation

Typography

By examining the cooling rate of rocks that formed more than 10 miles beneath the Earth’s surface, scientists led by The University of Texas at Austin Jackson School of Geosciences have found that water probably penetrates deep into the crust and upper mantle at mid-ocean spreading zones, the places where new crust is made. The finding adds evidence to one side of a long-standing debate on how magma from the Earth’s mantle cools to form the lower layers of crust.

Nick Dygert, a postdoctoral fellow in the Jackson School’s Department of Geological Sciences, led the research which was published in May in the print edition of Earth and Planetary Science Letters. Collaborators include Peter Kelemen of Colombia University and Yan Liang of Brown University.

By examining the cooling rate of rocks that formed more than 10 miles beneath the Earth’s surface, scientists led by The University of Texas at Austin Jackson School of Geosciences have found that water probably penetrates deep into the crust and upper mantle at mid-ocean spreading zones, the places where new crust is made. The finding adds evidence to one side of a long-standing debate on how magma from the Earth’s mantle cools to form the lower layers of crust.

Nick Dygert, a postdoctoral fellow in the Jackson School’s Department of Geological Sciences, led the research which was published in May in the print edition of Earth and Planetary Science Letters. Collaborators include Peter Kelemen of Colombia University and Yan Liang of Brown University.

The Earth’s mantle is a semi-solid layer that separates the planet’s crust from the core. Dygert said that while it’s well known that magma upwelling from the mantle at mid-ocean spreading zones creates new crust, there are many questions on how the process works.

“There’s a debate in the scientific community how oceanic crust forms,” Dygert said. “And the different models have very different requirements for cooling regimes.”

Continue reading at: University of Texas at Austin

Image: The mantle section researched in the study came from ophiolite section in Oman. This image depicts a similar ophiolite section from the Bay of Islands in Newfoundland. Credits: Nick Dygert