Researchers reported the Turkana Rift Zone is in a rare “necking” phase, a point-of-no-return stage in which continental crust rapidly thins before splitting apart.
Archival seismic data from Kenya and Ethiopia showed one section of crust is just under 13 kilometers thick, far below the roughly 30 kilometers typical of continental crust.
The team estimates the rift has been necking for about 4 million years, with the center subsiding as stretched crust sank toward the mantle.
That subsidence may also help explain Turkana’s rich fossil deposits, because low-lying basins trap sediments that can preserve ancient remains.
If thinning continues into oceanization, magma could create new oceanic crust and, over millions of years, open an ocean that separates part of eastern Africa.
As Africa splits at a 'point of no return,' what will our future world map actually look like?
Is the 'cradle of humanity' a geological accident that perfectly preserved our ancestors' fossils?
Turkana Rift Enters Critical Necking Phase: Landmark Discovery Reveals Africa’s Imminent Continental Breakup and Birth of a New Ocean
Overview
The Turkana Rift, where the African and Somali plates are pulling apart, is undergoing dramatic changes as the Earth's crust stretches, thins, and fractures. This process has led to significant crustal thinning, allowing magma from the mantle to rise into the expanding gaps. Recent seismic studies reveal that the Turkana Rift is the first active continental rift to enter the critical 'necking' phase, where the crust becomes extremely thin, like the neck of a bottle before breaking. This marks a major step toward the eventual breakup of the continent and the formation of a new ocean basin.