Geologists recover controversial missing tectonic plate that some assumed never existed.
The presence of a tectonic plate dubbed Resurrection has been a topic of controversy among geologists for a very long time, with some contending it was never real. Others opined that it subducted – that is shifted sideways and beneath – into the earth’s mantle someplace in the Pacific Margin between 40 and 60 million years ago.
However, presently a team of geologists at the University of Houston College of Natural Sciences and Mathematics conclude that they have discovered the lost plate in northern Canada by utilizing existing mantle tomography images – identical to a CT scan of the earth’s core. The outcomes, published in Geological Society of America Bulletin, could enable geologists predict the volcanic hazards better as well as mineral and hydrocarbon deposits.
“Volcanoes form at plate boundaries, and the more plates you have, the more volcanoes you have,” said Jonny Wu, assistant professor of geology in the Department of Earth and Atmospheric Sciences.
“Volcanoes also affect climate change. So, when you are trying to model the earth and understand how climate has changed since time, you really want to know how many volcanoes there have been on earth.”
Wu and Spencer Fuston, a third-year geology doctoral student, used a technique created by the UH Center for Tectonics and Tomography dubbed slab unfolding to reconstruct what tectonic plates in the Pacific Ocean looked like during the early Cenozoic Era. The inflexible outermost shell of Earth, or lithosphere, is cracked into tectonic plates and geologists have always discerned that there were two plates in the Pacific Ocean at that duration called Kula and Farallon. But there has been debate about a possible third plate, Resurrection, having formed a unique type of volcanic belt along Alaska and Washington State.
“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 supports,” Fuston said.
With the aid of 3D mapping technology, Fuston referred to the slab unfolding technique to the mantle tomography images to draw the subducted plates before unwrapping and stretching them to their initial shapes.
“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,” explained Wu.