New research recalibrates the age of the Jordan Valley’s Ubeidiya Formation to nearly two million years, putting it on par with the famous site of Dmanisi in Georgia. This could mark a pivotal moment in human evolution — evidence that early hominins with advanced tool-making techniques ventured into novel environments much earlier than assumed.
This is an artist’s reconstruction of Homo erectus. Image credit: Yale University.
The archaeological site of Ubeidiya is located in the Jordan Valley of Israel, between the village Menahemia and the kibbutz Beit Zera.
First discovered in 1959, the site yielded distinctive Acheulean handaxes, but only few hominin fossils.
“The Ubeidiya Formation has long interested researchers because it preserves early evidence of the Acheulean culture, characterized by large bifacial stone tools found in association with rich faunal assemblages, including species of African and Asian origin, some of which are now extinct,” said Hebrew University of Jerusalem’s Professor Ari Matmon and colleagues.
“However, establishing the site’s exact age has been a challenge for decades.”
“For many years, most researchers estimated that Ubeidiya dated to between 1.2 and 1.6 million years ago but this age was based on relative chronology.”
To determine the precise age of the site, the researchers used three independent dating methods: magnetostratigraphy, uranium-lead (U-Pb) dating of mollusk shells, and cosmogenic isotope burial dating.
“Cosmogenic isotope burial dating measures rare isotopes created when cosmic rays strike rocks at the Earth’s surface,” they explained.
“Once those rocks are buried, the isotopes begin to decay at predictable rates, effectively starting a geological clock that reveals how long they have lain underground.”
“We also examined traces of Earth’s ancient magnetic field preserved in the site’s lake sediments,” they added.
“As sediments settle, they lock in the direction of the planet’s magnetic field at that moment.”
“By matching these magnetic signatures to known reversals in Earth’s history, we determined that the layers formed during the Matuyama Chron, a period that began more than two million years ago.”
“Finally, we analyzed fossilized Melanopsis shells, freshwater snails embedded in the sediment, using U-Pb dating to establish a minimum age for the layers in which the stone tools were discovered.”
“Altogether, the results converged on a significantly earlier date than previously assumed.”
A bifacial stone tool from the site of Ubeidiya in Israel. Image credit: Omry Barzilai.
The team’s results indicate that the Ubeidiya site is at least 1.9 million years old, significantly older than previous assessments.
“The new timeline suggests that ‘Ubeidiya is roughly the same age as the well-acknowledged Dmanisi site in Georgia, which means our ancestors were spreading across different regions at a similar time,” the scientists said.
“It also suggests that two different technologies of making stone tools, the simpler Oldowan tradition and the more advanced Acheulean, migrated at the same time from Africa by the different groups of hominins as they moved into new territories.”
The study was published in the journal Quaternary Science Reviews.
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A. Matmon et al. 2026. Complex exposure-burial history and Pleistocene sediment recycling in the Dead Sea Rift with implications for the age of the Acheulean site of ‘Ubeidiya. Quaternary Science Reviews 378: 109871; doi: 10.1016/j.quascirev.2026.109871
