One of the world's most important plate boundaries is older than previously thought

A chain of remote islands and underwater volcanoes between Alaska and Kamchatka has revealed a much older chapter in Earth's tectonic history than previously known. Along the Aleutian Arc, the Pacific Plate dives beneath the North American Plate, creating one of the most active and important plate boundaries on Earth. An international research team has now shown that this subduction zone began at least 56 million years ago, significantly earlier than previous models had assumed. The findings, published in Nature Communications, shed new light on a major reorganization of plate motions and may also help better understand ancient global climate change.