In northern Guizhou in May, rain and sunshine often pour down, and the warm and moist air urges the growth of everything.

Suiyang County, close to the urban area of Zunyi, is a famous "poetry town" with rich cultural heritage. However, Suiyang not only has poetry The other side of human fame is the natural ecology.

Underground river at the entrance of the scenic spot

Drive from Suiyang County to Shuanghe Village, Wenquan Town in about 50 minutes. At the entrance of Shuanghe Cave in the scenic spot behind the 12th Five Year Plan, the underground water turns from dark to bright, meanders along the stream, nourishing the earth and all things.

"Although it is very gentle now, it has a very strong side, like a sharp knife, carving a magnificent Shuanghe Cave.

Cave landscape

On April 9, the kick-off meeting of scientific research on Shuanghe Cave's application for world natural heritage was held. Shuanghe Cave has the confidence to apply for World Heritage -- as“ The longest hole in Asia " , Shuanghe Cave is winding and rugged, The depth of the tunnel is 912m, and 107 openings are connected, The total length of the system connection is 409.9km, and the length of the hole is enough to cross the south and north of Guizhou, which is equivalent to the straight distance from Daozhen Autonomous County in the north to Pingtang County in the south.

Shuanghe Cave , a hundred million years at a glance, precipitated by the thickness of time Heavy, but also hidden nature's uncanny workmanship. 30 year scientific research, Shuanghe Cave It shows the vicissitudes of this land to the world.

Shuanghe Cave, known as the "Museum of Karst Natural Caves", hides "another Guizhou".

 

107 caves breathing dolomite caves in karst

 

Standing in the distance, the mountain looks like a giant with open mouth. As soon as I entered the cave, I felt chilly and the light became much darker. When I walked inside, the whole figure was engulfed by darkness, and I could only rely on the landscape lights in the cave to illuminate the way forward.

In the cavity, the delicate makeup of the earth changes 360 degrees in an instant, and lines of different shades on the rock wall stack each other like folds. It is hard to imagine what geological and geomorphic changes Shuanghe Cave has experienced.

Side rock dam in tunnel

Compared with the limestone caves commonly seen in typical karst landforms, the Shuanghe Cave formed in dolomite and dolomitic limestone rock formations is unique. Geological wonders such as cave waterfalls, curly stones, gypsum crystal flowers, lapis lazuli, and border rock dams, as well as the discovery of cave fossils and living bodies, have provided precious materials for scientific research.

Then the landscape lights looked up. The circular groove on the top of the cave was like an inverted pot, and a number of irregular oval patterns spread outward from the center, as deep as the vast universe, making people fascinated; Looking down, the huge rock was torn by the water flow, and the clear underground river flowed in the long and narrow ground fissure, sometimes appearing, sometimes slow, sometimes urgent.

"This is the famous" Tianguo "in Shuanghe Cave, carved by the water flow millions of years ago." Li Quanzheng, a staff member of the Comprehensive Section of the Management Office of Suiyang Shuanghe Cave National Geopark, said that in the future, a small pool will be built directly below the most beautiful "Tianguo" in Shuanghe Cave, and the "mirage" will be built up and down for tourists to enjoy.

In a cave Underground river

The silent confrontation between flowing water and carbonate rocks lasted for several years. "The water flow is like a diligent porter. It erodes the rocks in one place and then transports them to other areas for accumulation, creating a variety of karst caves," said Ran Xiuwu.

Looking along the beam, the particles in the air were visible to the naked eye, and Li Quanzheng couldn't help but take a big gulp: "Shuanghe Cave is a hole that can breathe. This is not dust but fog drops, and visible negative oxygen ions."

Shuanghe Village is surrounded by dense virgin forest, and the forest coverage rate of the scenic spot behind the 12th Five Year Plan exceeds 60%. There are complete caves, forests, mountains and water in the area. According to the detection, the content of negative oxygen ions in some caves is about 50000/cm3.

Cave landscape

"There are almost no plants growing in the cave, but people do not feel anoxic when walking inside. The air is exchanged in real time through the portal and surrounding rock cracks, and the humidity and temperature are relatively stable," Li Quanzheng said.

In fact, Shuanghe Cave is not airtight, but has 107 openings connected to each other, and it is not from head to tail, but complex, with 4 layers in total. On the horizontal plane, the internal holes are connected with each other and the holes are nested inside the holes. In the vertical direction, there are holes on the holes and holes under the holes. The vertical shaft "elevator" created by water is connected.

"Water can cut high and fill low, which is a very magical medium. The caves flowing through underground rivers mean that they are growing, just like people's youth; while some caves have less water flow, belonging to the middle age; and some caves belong to dry caves, just like an old man in his later years, who will basically not grow again." Ran Xiuwu said so.

Huge cavity

The stratum where Shuanghe Cave is located is a soluble rock with dolomite as the main body, and its area and overall thickness are huge. How did Shuanghe Cave come into being? This problem puzzles many scientific examiners.

The Yunnan Guizhou Plateau is a part of the ancient ocean. The Cambrian strata of Loushanguan were torn into "X" shaped fractures under the action of geological movement. Kuang Guangxian, Chief of Business Section of Shuanghedong National Geopark Management Office, said that dolomite is extremely insoluble in texture, and many geologists do not believe that such a cave can be developed in dolomite.

"The genesis of Shuanghe Cave is very complex. The stratum where it is located is relatively stable, and there is no large fault passing through. The attitude of the rock stratum is gentle. The formation of a wide tunnel is due to sulfuric acid, mechanical collapse, condensation corrosion and other reasons in addition to water flow." said Wang Deyuan, assistant researcher of the Institute of Mountain Resources, Guizhou Academy of Sciences.

  Knock on the door of the center of the earth and talk to the ancient visitors of the cave and abyss

 

Compared with the dark and deep caves, the white light from the headlights is too weak, and the visual range of the naked eye is very limited. When tourists pass by, there may be a few "chirping" sounds. Some sleeping bats are awakened and quickly flap their wings to spread out.

"Everyone should adjust the angle of the headlights and look at the road carefully." Ran Xiuwu, the director of the exploration of the Twelve Back Tourist Scenic Spot, often reminds tourists. The "road" at the foot is actually made of steel pipes straight into the cliff.

Bats taking a nap in the cave

"This plant has strong vitality!" Compared with the dense bushes outside the cave, there are few plants in the cave. On the rock wall of a cave, a fern hanging upside down in a crack in the rock attracted everyone's attention.

When walking in Shuanghe Cave, you may bump into many kinds of cave "elves", such as Flying Cat, Spotted Kitchen Horse, Blind Bu Jia, etc. The natural sounds they make from time to time add some vitality to the silent cave.

In the remote years, the ancient land of Guizhou began to clamour. Marine creatures roamed aimlessly with the ocean current, and land animals played leisurely in the forest for food. For several years, due to geological movement, climate change, human activities and other reasons, a wide variety of biological fossils have become part of the "kingdom of paleontology" in Guizhou.

The creatures in the cave

Each fossil contains unique historical information. The creatures that left traces in Shuanghe Cave, in a new identity, crossed the "stone" space, talked with modern people who entered the cave, and told about different geological changes and life evolution in Guizhou.

The 409.9km tunnel has formed many relatively independent local environments, and there is little external interference, so the original features have been preserved relatively completely. For scientific researchers, Shuanghe Cave is like a key to open the door of the geocenter.

"Scientific researchers once found giant panda fossils here." Li Quanzheng's words made everyone who had walked for nearly two hours and felt a little tired suddenly refreshed. Close to the wall and listen, the water in the narrow hole ticks.

Since the scientific research, more than 40 giant panda fossils have been found in Shuanghe Cave, including several relatively complete individuals, which provides good conditions for researchers to carry out systematic evolution research on giant pandas.

Giant panda fossils found in the cave (photo source: Institute of Mountain Resources, Guizhou Academy of Sciences)

In 2021, during the joint scientific research at home and abroad, researchers found the "pseudo thumb" fossil at two complete bones of giant pandas. After measurement, its size is almost the same as that of the living giant panda.

"These two giant panda fossils are extremely well preserved and rare in the world. According to dating, one lived 102000 years ago and the other lived 49000 years ago." Wang Deyuan said.

In terms of grasping bamboo for food, the limbs of giant pandas show a special evolutionary adaptation phenomenon: compared with other bears, giant pandas have an extra "thumb" on their palms. This "thumb" is formed by the enlargement of the radial sesamoid bone, not the real thumb. It is called "pseudo thumb" when it grabs bamboo together with other five "fingers".

The living giant panda belongs to the carnivorous order Ursidae, and is fond of eating bamboo. Previously, due to the lack of fossil evidence, the time when giant pandas will transition to the era when bamboo is the main food has not been well determined. The fossil of radial sesamoid (pseudo thumb) found in Shuanghe Cave in Suiyang provides important evidence for understanding the bamboo eating characteristics of giant pandas.

Giant Panda Fossils Found in the Cave (Picture source: Institute of Mountain Resources, Guizhou Academy of Sciences)

"In Shuanghe Cave, there are clusters of complete grape shaped stalactites with black and shiny color." "Swordtooth elephant fossils and rhinoceros fossils have been found in Shuanghe Cave." "Blind fish and tadpoles with degenerated eyes and translucent bodies can only be seen in the cave with good luck." ……

Li Quanzheng walked all the way and counted the family details of Shuanghe Cave scientific research with his fingers. Shuanghe Cave, with a well-developed cave system, contains a large number of precious resources, creating good conditions for applying for the World Natural Heritage List.

At present, only water caves, gypsum caves, Hejiao caves and underground cracks are open to the public in Shuanghe Karst Cave Group. In Shuanghe Cave, a new energy sightseeing car with a retro shape drives at a low speed in the cave cavity. Tourists stop and go to experience the little-known secret land of Guizhou. It usually takes an hour for a nearly 2km tunnel.

Opening

"Shuanghe Cave is not only a natural wonder, but also a precious art treasure house. It is amazing that the power and beauty of nature are displayed everywhere. Too much human activity will damage the ecosystem of the cave, so it needs to be protected in development and developed in protection when applying for the World Heritage." Li Quanzheng said.

 

409.9km underground "marathon" scientific research relay race

 

There are many karst landforms in southern China. Where is the bottom line when Shuanghe Cave is declared as a world natural heritage?

"Shuanghe Cave system has a large scale of unique geological landscape, especially the world's longest dolomite cave system and the world's largest celestite cave." Kuang Guangxian answered simply.

Stalactites in the cave

"Cave exploration is a long-term challenge, and the road we are going through is all the areas that have been visited by previous groups of scientific researchers. When you walk, you should carefully observe up, down, left and right. Maybe there is a fossil from ancient creatures hidden in the stone you step on." Ran Xiuwu teased everyone on the way.

On the yellowish brown rock wall, some water droplets are leached from the permeable pores, and slowly gather downward under the action of gravity to flow into the underground river. "Before setting out, researchers cannot know where the end of the tunnel is, or whether it is connected to other caves, and water flow is a good guide," Li Quanzheng said.

In January 2004, Shuanghedong was approved by the former Ministry of Land and Resources as the third batch of national geological parks in China. Since then, the scientific research of caves has been accelerated, and a number of scientific research achievements released have attracted wide attention.

Winter dry season is the best time for scientific research. At this time, many Chinese and foreign cave explorers and scientific researchers have come to Suiyang County to investigate Shuanghe Cave. Wearing exploratory suits, helmets with lights, and climbing ropes in hand, all of us set out in groups of at least three towards the unknown area of Shuanghe Cave to explore the mysteries of the cave.

Scientific research personnel are conducting scientific research

Finding out the family background of Shuanghe Cave is a key step in applying for World Heritage. The length of a hole is equal to the total length of all main holes, branch holes, shafts and underground rivers in the cave system. Each measurement takes a lot of effort of the caver.

Since 1987, after years of exploration by a group of Chinese and foreign scientific research experts, such as Yang Hankui, Li Po, He Wei, Jean Botasi, Zhou Wenlong, Gao Zhandong, etc., Shuanghedong has been "long" and the mystery has been constantly uncovered.

100 km in 2006, 200 km in 2007, 2018 238.48 kilometers, becoming the first long hole in Asia From the initial 17 km to 409.9 km, one record after another was set.

"In addition to the length, the genesis of caves, the excavation of the scientific research value of animal fossils, and the protection of caves are also worthy of attention. At present, we are using advanced technology to provide more scientific research results for the World Heritage application." Wang Deyuan said.

Since the first application for World Heritage in 2003, Guizhou Province has successfully obtained four world natural heritage sites and one world cultural heritage site, becoming a provincial administrative region with the highest number of world natural heritage sites nationwide.

Crystal flower stone in the cave

In 2021, the Geoscience World Heritage: A Global Framework for the Application of the World Heritage Convention (viii) (Geological and Geomorphological Standards) issued by the World Conservation Union pointed out that there may still be potential areas that meet the geological and geomorphological standards. Although Shibing is a dolomite landform, caves with well-developed dolomite are still blank.

"This provides a very important international basis for Shuanghe Cave to apply for the World Natural Heritage. Shuanghe Cave has a long way to go, which is of great significance and worth looking forward to," said Kuang Guangxian.

Pan Xiaofei, reporter of Guizhou Daily Tianyan News

The video material of this article is provided by Suiyang County Rong Media Center

Edited by Luo Qiuhong

Second instance Wang Yu

Third instance: Yue Zhen