Recently, a scientific discovery in Qingchuan County, Sichuan province provided a possible clue about what precipitated the largest mass extinction in the earth's history, which happened 250 million years ago, Chengdu Business Daily reported.

Zheng Quanfeng, an associate researcher at the Nanjing Institute of Geology and Paleontology under the Chinese Academy of Sciences, found the rare geological site, a 50,000-square-meter bed of rocks and fossils. The site was once a deep sea, though it developed into sedimentary stratum from the late Permian period to the early Triassic. Given its record of the mass extinction during the late Permian period, the site has extraordinary scientific value, Zheng said.

The researcher explained that there was a substantial warming of about 10 degrees Celsius in the area roughly 250 million years ago, which occurred after the Permian extinction. This new evidence indicates that the rise of ocean temperatures might not have been the main cause of that extinction. The discovery also suggests that low oxygen levels in the water are not to blame for the extinction.

At the same time, the presence of volcanic ash layers in the rock beds of the geological site indicates large-scale volcanic eruptions caused by changes in the earth's crust. These eruptions are the likeliest cause of the late Permian mass extinction.

Zheng expressed hope that the scientific community would pay special attention to protecting the site. He recommended that a small number of fossils be collected and preserved, and that the larger site be designated a geological relic protection zone. A national geological park or museum could also be constructed, or the area could be built into a tourist site complete with a student education base.