Tracing footsteps in volcanic stone

Blade cores recently discovered in an archaeological survey in Antu county, Jilin. [Photo provided to China Daily]

At the Jidi site, archaeologists found a giant blade core (a mother tool used for detaching blades) measuring 53 centimeters in length. Its scale and craftsmanship are rarely found anywhere in the world, says Xu. Together, the sites provide a continuous record of human activity from about 220,000 to 15,000 years ago.

By at least 50,000 years ago, people were already deliberately selecting obsidian for tool production. Around 28,000 years ago, they developed blade and microblade technologies that improved efficiency, mobility, and adaptability.

"Overall, with abundant obsidian and animal and plant resources, ancient people in the Changbai Mountain area thrived and developed from 220,000 to 15,000 years ago. Through continuous technological advances, they gradually refined their skills and eventually entered the Neolithic period around 15,000 years ago," says Xu.