Time Span of the Great Rift
Published on: 08/20/2012
The Great Rift Valley of East Africa—the birthplace of the human species—may have taken much longer to develop than previously believed, according to research published in Nature Geoscience.
"We now believe that the western portion of the rift formed about 25 million years ago and is approximately as old as the eastern part, instead of much younger as other studies have maintained,” says Michael Gottfried, MSU associate professor of geological sciences. “Our study has major implications for the environmental and landscape changes that form the backdrop for that evolutionary story.”
Gottfried worked with an international team led by Eric Roberts at Australia’s James Cook University who added that the findings have important implications for understanding climate change models, animal evolution and the development of Africa’s unique landscape.
Traditionally, the eastern branch is considered much older, having developed 15 to 25 million years earlier than the western branch. This study provides new evidence that the two rift segments developed at about the same time, nearly doubling the initiation age of the western branch and the timing of uplift in this region of East Africa.
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