Since 1988, geologists from Britain, Australia, Germany and the United States, have made spot inspections at a mountainous area in Luodian County in southwest China's Guizhou Province, hoping to find evidence for the mass extinction 250 million years ago among fossils from the late Permian and early Triassic periods.

There have been six mass extinctions on earth. Among them, the most massive and influential was the extinction that occurred at the end of the Permian Period some 250 million years ago, when more than 90 percent of marine life perished in a short period of time. Only a small amount of primitive life remained.

The precise cause of that extinction remains a mystery.

In Loudian County, frequented by both Chinese and foreign geologists, the core area called Big Guizhoutan, or Big Guizhou Shoal, is praised as a "treasure land for Triassic Period research."

Geologists have found that prior to the Permian extinction, the earth experienced a major environmental change. However, areas around the Big Guizhoutan were barely affected.

Mike Orchard, president of the Triassic stratum department of the International Commission on Stratigraphy, said, "A variety of factors conspired toward the Permian extinction. China has provided unique fossils for research in this case and has made productive research in this field."

(Xinhua News Agency August 19, 2005)