Ancient Forest Discovered in Remote China Sinkhole

Karst mountains in the Guangxi region of China, where the sinkhole was discovered. (Photo: MediaProduction / Getty Images)

Chinese scientists from the Institute of Karst Geology of the China Geological Survey have uncovered a “lost world” at the bottom of a massive sinkhole in China. The cave exploration team discovered a giant karst sinkhole in south China’s Guangxi Zhuang Autonomous Region, bringing the number of such sinkholes in the county to 30.

The sinkhole measures 306 meters in length, 150 meters in width and 192 meters in depth, with its volume exceeding 5 million cubic meters, and can be categorized as a large sinkhole. The bottom of the sinkhole has a well-preserved primitive forest.

The newly found one will help the team carry out further comparative studies, which may expand their understanding of the karst landform in the future. According to reports, “after first rappelling over 98 meters into the abyss, Chinese spelunkers and speleologists from the Institute of Karst Geology of the China Geological Survey found themselves trekking through a dense forest to reach the bottom.” 

This giant karst sinkhole, also called a tiankeng, has plants growing at the bottom in Luoquanyan Village of Xuan’en County, central China’s Hubei Province. Note: This is not the sinkhole discovered in Guangxi Zhuang Autonomous Region. (Image credit: Song Wen/Xinhua/Alamy Live News)

The primeval landscape features ancient trees with heights in excess of 40 meters, as well as massive shade plants as tall as the explorers’ shoulders. The previously-undisturbed site is so inaccessible that researchers believe it may be home to unique species of plants and animals. 

“I wouldn’t be surprised to know that there are species found in these caves that have never been reported or described by science until now,” Chen Lixin, leader of the expedition team, told Xinhau

Video: 30th giant karst sinkhole discovered in south China’s Guangxi

The discovery is the 30th such sinkhole that has been found in the mountainous Guangxi region, part of a 240,000-acre UNESCO World Heritage site known as the South China Karst. The karst topography is formed by the dissolution of soluble rocks such as limestone from rainwater, which leads to the formation of extensive cave system and sinkholes. 

According to Livescience, an estimated 20% of the world’s landmasses is made from karst or psuedokarst. In Mandarin, massive sinkholes like those found in Guangxi are known as “tiankeng,” or “heavenly pits.”

“So in China you have this incredibly visually spectacular karst with enormous sinkholes and giant cave entrances and so forth,” George Veni, the executive director of the National Cave and Karst Research Institute (NCKRI) in the U.S., told LiveScience. “In other parts of the world you walk out on the karst and you really don’t notice anything. Sinkholes might be quite subdued, only a meter or two in diameter. Cave entrances might be very small, so you have to squeeze your way into them.” 

Treehugger said “Squeezing into sinkholes isn’t generally a problem in China, where words like “enormous” do not do justice to the incredible wonders dotting its karst topography. As you might expect, it’s also home to the world’s largest sinkhole, the Xiaozhai Tiankeng”, which spans 617 meters long, 527 meters wide, and burrows between 503–652 meters into the earth.

Video: Exploring Chongqing: What are the Heavenly Pit and Earthly Ravine?

Tiankeng Difeng, which is translated to Heavenly Pit and Earthly Ravine, is a scenic spot located near Fengjie County in southwest China’s Chongqing Municipality. Visitors can see various kinds of karst landforms, such as stone forests, caves, valleys, etc. The spot has been the fairyland for geological enthusiasts and paradise for explorers.

See video of the mammoth Tiankeng Difeng sinkhole (right).