Microblade (left) and bladelet (right) cores found at the Xinmiaozhuang site in Zhangjiakou, Hebei province.

Microblade (left) and bladelet (right) cores found at the Xinmiaozhuang site in Zhangjiakou, Hebei province.

Excavations in 2022 at the same site.

Chinese archaeologists have discovered evidence of a pivotal stone tool technology dating back 30,000 years at the Xinmiaozhuang site in Zhangjiakou, Hebei province's Nihewan Basin, often called the "Homeland of Eastern Humans".

The discovery of bladelet (narrow, small, and elongated flakes) technology fills a crucial missing link in understanding the origins of later, more refined microblade technology in North China.

"It acts like a key, unlocking the door to a technological transition that happened tens of thousands of years ago," says Wang Fagang, 45, the lead archaeologist at the Xinmiaozhuang site and a researcher with the Hebei Provincial Institute of Cultural Relics and Archaeology.

The story of Xinmiaozhuang is one of persistent pursuit. The site was briefly excavated in 1986, yielding over 5,000 stone artifacts. The remote location was later lost to researchers due to changes in the landscape and imprecise records.

Wang first encountered the legend of this lost site nearly 20 years ago as a young graduate.

"We came looking, but the landscape had changed. We even thought road construction might have destroyed it," he says.

The breakthrough came in 2014 when senior archaeologist Xie Fei, after comparing a newly found soil exposure with a faded 1986 black-and-white photo, made the connection, according to a report by Hebei Daily.

Since systematic work began in 2016, nearly 30 Paleolithic sites have been identified in the small mountain basin. Formal excavations started in 2022.

According to Wang, from 2022 to 2024 at Locations 1 to 5, six consecutive periods of cultural deposits were identified spanning from 120,000 to 10,000 years ago. These encompass various technologies such as flake tools, Mousterian-style stone tools, bladelets and microblades.

The 2025 excavation focused on two areas within the site complex — Location 4 and 20. At Location 20, archaeologists uncovered two clear cultural layers.

The upper layer contained the remains of typical microblade technology from about 27,000 years ago, further enriching the record of the earliest stage of microblade technology in North China.

Beneath it, in a layer dating back 30,000 years, the critical evidence was found: bladelet cores and related tools.

"When the bladelet core was fully exposed, we had a feeling that this might be the transitional stage we had been looking for," Wang says.

The origin of North China's highly developed microblade technology has long been debated.

This newly discovered bladelet technology sits perfectly between the earlier blade technology found at the site (dated to 45,000 years ago) and the later microblade technology that appeared about 27,000 years ago.

"The significance is immense," says Gao Xing from the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences.

"It shows the technological change here was not a sudden replacement from outside, but a gradual, internal evolution."

Xinmiaozhuang offers more than just a timeline of toolmaking.

Over 100 personal ornaments, primarily beads made from ostrich eggshells, have been unearthed. The earliest of these, dating back about 39,000 years, are the oldest decorations found in North China to date. Some are pierced, others are incised with lines or shaped like fish.

"These items were not necessities for survival," Wang says. "They represent adornment, aesthetics and symbolic thinking."

Another striking discovery came in 2024 at Location 5, where archaeologists exposed what they call a "stone tool workshop".

Over 70,000 stone artifacts — waste flakes, rejects and half-finished tools — were concentrated in one area.

"It was as if we could see a craftsman sitting there, constantly chipping away," Wang says.

At the bottom sat a ring of fire-cracked stones, a primitive furnace used for heat-treating stone to improve its workability. It is the first clear facility of its kind from the Paleolithic period in East Asia.

The site is located deep in the mountains. The team commutes daily on rough tracks spanning about 12 kilometers.

"It's the most challenging site I've worked on," says Bai Shijun, a field technician with over 20 years of experience.

For Wang and his team, each answer leads to new questions. When exactly was the first microblade pressed? What prompted the creation of the first ornament?

"In archaeology, exploration truly has no end. I am particularly eager to find that moment when ancient human technology underwent a transformation," he says.