This article is reproduced from Xinhua News Agency

Reporters Hu Jiali, Lin Fanshi, Wang Wei

After an expedition in Leye County, Guangxi, organized by the Institute of Karst Geology of the China Geological Survey of the Ministry of Natural Resources, the expedition team confirmed on May 7th that a standard tiankeng was found. So far, the number of tiankeng in Leye County, known as tiankeng city of the world, has increased to 30.

Aerial photo of the newly discovered Tiankeng in Leye, Guangxi. (photo by Guangxi 702 Cave Expedition Team)

Zhang Yuanhai, a senior engineer of the Institute of Karst Geology of China Geological Survey, introduced that the diameter of the tiankeng is 306 meters long from east to west, 150 meters wide from north to south, the maximum depth is 192 meters, the average depth is about 139 meters, and the volume exceeds 5 million cubic meters. It meets the standard of tiankeng.

This tiankeng is located near Longao Village, Ping'e Village, Luoxi Township, Leye County. On August 6th, a scientific expedition team, jointly formed by Karst Geology Research Institute of China Geological Survey, Guangxi 702 Cave Expedition Team, and Leye Flying Cat Expedition Club, went to the top of the tiankeng and rappelled along the cliff for 100 meters. They reached the bottom after several hours’ descending and returned to the ground that night.

Chen Lixin, leader of the Guangxi 702 Cave Expedition Team, said that the expedition team had overcome many obstacles to reach the bottom of the tiankeng. They moved slowly down the slope of the complex boulders, passed through the dense underground forest and finally reached the lowest point at the bottom of the tiankeng, where they found that the older trees growing centrally towards the top of the tiankeng are nearly 40 meters high, and the dense shade plants almost are as tall as a man .

Zhang Yuanhai said that there are three large holes on the wall of the tiankeng, which are presumed to be the remaining traces of the cave in the early evolution of the tiankeng. The bottom of the tiankeng is a well-preserved primeval forest system, in which are a large number of collapsed rocks. "All the evidence of the evolution of the tiankeng or the unique ecosystem after the formation of the tiankeng are of high scientific value and popular science value", said Zhang.

Leye County is a typical karst area in southern China. It is the location of Dashiwei Tiankeng Group, which is the largest tiankeng group in the world. There are 29 Tiankengs that have been discovered before the new finding, and it is known as the Tiankeng Museum of the World.

"Tiankeng is formed by a hall in a carbonate rock area with a diameter and depth of not less than 100 meters, reaches or exceeds a volume of 1 million cubic meters, surrounded by cliffs or most of the surrounding walls are cliffs. “This kind of caves may have been connected with underground rivers and the shape of them should be like a large funnel”, Zhang said. He also introduced that the newly discovered tiankeng did not belong to the Dashiwei Tiankeng Group, but was developed in another underground river system, the Fugui Underground River. “Whether there is any other underground river system or other tiankeng and karst wonders needs further investigation.’’ Zhang finally said.