Geologists Link Grand Canyon's 1.2 Billion-Year Gap to 8 Kilometers of Ancient Erosion
Updated
Updated · IFLScience · Aug 20
Geologists Link Grand Canyon's 1.2 Billion-Year Gap to 8 Kilometers of Ancient Erosion
3 articles · Updated · IFLScience · Aug 20
Summary
A new Geology study says the Grand Canyon’s 1.2 billion-year rock gap may reflect up to 8 kilometers of crust stripped away after Rodinia began breaking apart more than 600 million years ago.
The team argues that rifting thinned the crust and upper mantle, setting off a migrating mantle wave that uplifted land and created a continent-scale mega-escarpment vulnerable to intense erosion.
That escarpment may have stretched from present-day Arkansas toward Canada’s north coast, with the Grand Canyon sitting about 500 kilometers inland from the ancient continental margin—similar to modern escarpments in South Africa and Brazil.
The authors say the mechanism could work alongside glaciers and rivers, but contend Rodinia breakup best explains why the Great Unconformity is strongest on continents once clustered around Rodinia’s core.
Beyond the canyon, the proposed uplift and erosion would have reshaped western North America’s rivers, sediment flows and early Cambrian shorelines, recasting the landmark as part of a much larger tectonic system.