They said that the two resources are stored in the Jurassic stratum, a 180-million-year-old geological formation which was thought to be only good for producing coal.

After years of exploration and research in the vast northwest, the scientists have concluded that oil and natural gas can also be produced there if the coal stratum is mature enough.

"The theory that oil can be formed in the Jurassic stratum is a breakthrough in China's oil exploration, and it will lead to more findings nationwide," said Dai Jinxing, an academician of the Chinese Academy of Engineering.

Chinese scientists have put focus on the Jurassic stratum and produced initial findings, Dai said.

Exploration teams have discovered 23 oil and gas fields in the Xinjiang Uygur Autonomous Region over the past several years; all are in the Jurassic stratum.

Scientists say that there are 60 basins with 1.46 million square kilometers of Jurassic area that might hold abundant oil and natural gas in the provinces and autonomous regions of Shanxi, Gansu, Qinghai, Ningxia, Xinjiang and the Inner Mongolia in northwestern China.

"To find big oil fields, our main target will be the Jurassic stratum in the coming years," said Dai.

(People's Daily 10/10/2000)