Construction workers have unearthed more than a dozen sea shells dating back 10,000 years -- a key archaeology discovery -- at the hi-tech zone in northern China's industrial city of Tianjin, archaeologists said.

The shells were found 17 meters underground earlier this month.

The city's geological survey and research institute Thursday confirmed the shells were a major discovery.

These shells can can help archaeologists understand the region's geological changes during the Holocene age, about 10,000 years to 12,000 years ago.

Shells unearthed in the past from Tianjin could only give archaeologists an understanding of geological changes going back 5,000 years.

(Xinhua News Agency May 15, 2010)