Menu

Geologists might have found a long-lost tectonic plate

Jonny Wu and Spencer Fuston
Jonny Wu (left), assistant professor of geology in the UH Department of Earth and Atmospheric Sciences, and Spencer Fuston, a third-year geology doctoral student, applied a technique developed by the UH Center for Tectonics and Tomography called slab unfolding to reconstruct what tectonic plates in the Pacific Ocean looked like during the early Cenozoic Era.

The existence of a tectonic plate called Resurrection has long been controversial among geophysicists. Some believe that it never existed, while others say that it is subducted into the Earth’s mantle somewhere in the Pacific Margin between 40 and 60 million years ago.

A new study by the University of Houston College of Natural Sciences and Mathematics shed light on this- suggesting that the Resurrection plate existed. Scientists believe they have found the remains of the missing plate, Resurrection in northern Canada-crushed, reshaped, and buried through subduction processes.

For this study, scientists used a technique developed by the UH Center for Tectonics and Tomography called slab unfolding to reconstruct what tectonic plates in the Pacific Ocean looked like during the early Cenozoic Era.

D block diagram across North America showing a mantle tomography image
A 3D block diagram across North America showing a mantle tomography image reveals the Slab Unfolding method used to flatten the Farallon tectonic plate. By doing this, Fuston and Wu were able to locate the lost Resurrection plate.

The rigid outermost shell of Earth, or lithosphere, is broken into tectonic plates, and geologists have always known there were two plates in the Pacific Ocean around then called Kula and Farallon. Be that as it may, there has been discussion about a potential third plate, Resurrection, which has shaped a unique volcanic belt along with Alaska and Washington State.

According to scientists, this study could help geologists predict volcanic hazards and mineral and hydrocarbon deposits.

    plate tectonic reconstruction
This image shows plate tectonic reconstruction of western North America 60 million years ago showing subduction of three key tectonic plates, Kula, Farallon and Resurrection.

Spencer Fuston, a third-year geology doctoral student, said, “We believe we have direct evidence that the Resurrection plate existed. We are also trying to solve a debate and advocate for which side our data support.”

Using 3-D mapping technology, scientists applied the slab unfolding technique to the mantle tomography images to pull out the subducted plates before unfolding and stretching them to their original shapes.

Jonny Wu, assistant professor of geology in the Department of Earth and Atmospheric Sciences, said, “When ‘raised’ back to the Earth’s surface and reconstructed, the boundaries of this ancient Resurrection tectonic plate match well with the ancient volcanic belts in Washington State and Alaska, providing a much sought after link between the ancient Pacific Ocean and the North American geologic record.”

Journal Reference:
  1. Spencer Fuston et al., Raising the Resurrection plate from an unfolded-slab plate tectonic reconstruction of northwestern North America since early Cenozoic time, GSA Bulletin (2020). DOI: 10.1130/B35677.1

Leave a Reply

Your email address will not be published. Required fields are marked *