40,000-year-old site suggests multiple migrations of modern humans into Eurasia

Powder from ochre, an iron-rich rock, has been used as paint pigment by humans for hundreds of thousands of years.Kalicoba/Alamy Stock Photo

Some 40,000 years ago, a small group of foragers parked themselves on a riverbank in what is now northeastern China. Some split pebbles and bones to make small tools while others made a fire. And at least one experienced craftsperson concentrated on the primary task: grinding red, purple, and gray chunks of ochre into a vibrant powder that could have been used as paint.

Now, scientists have confirmed this prepared ochre is the oldest yet found in East Asia. Although no human fossils were uncovered, the finds suggest the ochre artisans were modern humans and part of a previously undetected migration into Eurasia.

Scholars often depict the spread of modern humans beyond Africa as one successful migration about 60,000 years ago, says Christopher Bae, a paleoanthropologist at the University of Hawaii, Manoa, who was not involved in the study. But he says the new site, called Xiamabei, indicates there were “multiple dispersals” into Asia. “I don’t think enough people have paid attention to that region. … It’s only a matter of time before there’s a lot more evidence found.”

Worldwide, people past and present have processed ochre for a multitude of tasks, including symbolic use in rock art and body painting, and as an ingredient in adhesives, sunscreen, and insect repellent. Because it takes knowledge and skill to turn the iron-rich rock into useful pigment, ochre processing has often been considered a marker for modern human behavior, especially when paired with sophisticated stone tools.

“Ochre provides insight into people’s knowledge of the world around them,” says Rachel Popelka-Filcoff, an ochre expert and archaeological scientist at the University of Melbourne. “You have to have the ability to procure it, to change its properties, to utilize it, and when talking about symbolic practices, you have to have communities around you to understand that symbolism.”

Researchers have unearthed evidence of Homo sapiens in China stretching back perhaps 100,000 years. And ancient DNA from a 40,000-year-old H. sapiens fossil only about 100 kilometers from the newly reported site presents a direct genetic line to some present-day Asians. But no ochre artifacts older than 35,000 years have been found in the region. Sophisticated slim stone points, another innovation typical of modern humans, don’t appear until 29,000 years ago.

Archaeologists at Xiamabei in China found an ochre-processing workshop on this excavation surface. Wang Fa-Gang

In 2013, Fa-Gang Wang, an archaeologist at the Hebei Provincial Institute of Cultural Relics and Archaeology, began excavating at Xiamabei, less than 150 kilometers east of Beijing. About 2.5 meters down, the team reached a surface where humans must have lingered many thousands of years ago. Across about 12 square meters—about the size of a parking space—the archaeologists recovered 382 stone artifacts, more than 400 bits of animal bone, and the remnants of a campfire. They also unearthed a patch of red dirt, accompanied by two chunks of ochre, a pestlelike cobblestone, and a limestone slab.

Using radiocarbon dating and optically stimulated luminescence—a technique that measures the time since sediment last saw sunlight—the team, joined by scientists from Europe and the Chinese Academy of Sciences (CAS), discovered the artifacts were between 39,000 and 41,000 years old, they report today in Nature. Given that ochre artifacts nearby are younger, they didn’t expect such an old date. “When the results came out … it really surprised us. Wow,” recalls Shixia Yang, lead author of the study and an archaeologist with CAS.

Although researchers couldn’t determine exactly what the ochre was used for, microscopic, mineral, and elemental analysis of artifacts and loose soil revealed the complexity of the workshop. The ancient people ground, polished, and pounded multiple types of raw ochre to create powders with distinct colors and grain sizes.

The stone artifacts also proved unique for the region and period. Made from chert and quartz pebbles, most measured less than 2 centimeters. The pebbles had been broken into tiny stones with sharp edges, hafted onto bone handles, and likely used for scraping hides, boring wood, and whittling plants. “They did a lot with these 2-centimeter things,” Yang says.

Together, Yang says, the artifacts suggest Xiamabei was “totally different” from contemporary sites in North China, which have different tools and show no evidence of ochre processing. The authors propose that the Xiamabei foragers belonged to a distinct group of Eurasian migrants, who may have crossed paths with other humans, such as Denisovans, as they spread to East Asia. They speculate that contact with other kinds of human could explain the unique assortment of artifacts.

But University of California, Davis, archaeologist Nicolas Zwyns thinks there’s no need to invoke Denisovans to explain the distinctive finds—modern humans may have simply adapted their repertoire in a new environment. Still, he says, the site provides good confirmation for innovations that are signs of modern humans spreading into Eurasia.