Introduction of karst landform scenic spots in China

The karst landforms in China are widely distributed. Hundreds of millions of years ago, most of southern China was a piece of Wang Yang Sea, which was also a part of the ancient Mediterranean. After hundreds of millions of years of natural geographical evolution, it has now become a continent, leaving many features of landform environment and karst landform mentality.

The karst landforms widely distributed in China dissolve the beautiful scenery, as well as the civilization and poetry.

Karst landform is named after the karst plateau in Slovenia. In China, Guilin, Guangxi is a typical karst landform area. Photo courtesy/creativity

Karst and water shape the landscape of the earth.

Karst is karst, which is a series of landforms formed when water meets soluble rocks and develops to a certain stage.

Hundreds of millions of years ago, the ancient Mediterranean Sea, larger than the present Pacific Ocean, crossed the southern part of Eurasia. More than half of China or Wang Yang. A large number of calcareous bones and other carbonate substances of marine life are continuously deposited, and thick carbonate rocks are formed on the seabed. Until tens of millions of years ago, the ancient Mediterranean receded from the south of China, and the seabed was lifted to land, from which deep carbonate rocks were distributed in China.

In tens of thousands of caves in karst areas in southern China, we can see carbonate rocks in the strata. Photography/Li Jin

When these soluble carbonate rocks meet running water, karst landforms appear.

The distribution of karst landforms in China is far wider than we thought. In the warm and rainy southern region, the annual precipitation is more than 1000 mm, and the rain pours down from nine days for thousands of years, eroding the earth and dissolving rocks at will, shaping the largest and most spectacular karst landform distribution area in the world; The precipitation in the north is far less than that in the south, and the annual precipitation is mostly 400-800 mm. Because the cracks in rocks can absorb more precipitation, groundwater erodes small caves and many karst springs are exposed.

In the arid western region, due to the lack of vegetation on the surface, rainwater can quickly enter the ground from cracks and form caves. Especially in the Kunlun Mountain area, glaciers and meltwater eroded, and some small-scale corrosion phenomena such as corrosion ditches and raindrop marks appeared on the limestone surface.

After thousands of years of erosion and dissolution by running water, stone forests, peaks, sinkholes, natural bridges, travertine and caves? The magnificent, colorful, steep and changeable karst landscape was born.

Karst landform is closely related to flowing water, showing different landscapes, and sometimes tiankeng, karst cave and peak cluster will appear together. Photography/Yao Qirong

Karst, how many landscapes are there?

With the blessing of time, the gentlest water dissolves grooves in hard rock layers, leaving steep stone buds, often as high as tens of meters. Clusters are distributed on vast rock formations and look like thousands of "rocky forests" from a distance. This is the famous stone forest in China's karst landform.

Shilin is mainly distributed in southern China, mostly in Yunnan, Guizhou, Hunan and Chongqing. According to incomplete statistics, the number can reach more than 40. In Lunan, Yunnan, the tall limestone columns are magnificent, including sword-shaped, columnar, mushroom-shaped and tower-shaped. There are various stone forests in different stages of development here, which are magnificent, just like an array of soldiers, forming a panoramic view of karst stone forests.

▲ Yunnan Shilin is listed in the World Heritage List by UNESCO because of its ancient, complex, multi-stage and rare nature. Photo courtesy/creativity

The stone forest as high as tens of meters is already a wonder, and the stone peaks as high as hundreds of meters are continuous, which is even more touching. In the hot and humid tropical and subtropical regions, the annual precipitation is as high as 1 500mm, the surface river network is vertical and horizontal, and the water flows on the carbonate rock layer with an average thickness of 10km, cutting out the Wan Ren with thousands of peaks and valleys, and the karst peak forests and clusters with towering peaks are magnificent and beautiful.

If there is a pedestal between mountains, it is called "peak cluster" Qibainong National Geopark is located in the northwest of Dahua Yao Autonomous County, Guangxi, and consists of more than 5,000 rocky mountains with an altitude of 800- 1 1,000 meters. The peaks are connected by pedestals, which is the most dense and typical karst peak cluster in the world. Looking around, the mountains are stacked, the heights are scattered, and the layers are superimposed, and the momentum is very majestic.

The main geological relics in Qibainong are peaks and deep depressions, and the wonders of mountains and seas are of great scientific research value. Photo courtesy/creativity

When the flowing water completely erodes the basement between mountains, the peak cluster will evolve into a scattered peak forest. Wan Fenglin, Xingyi City, Guizhou Province is the largest and most typical karst peak forest in China, with 10,000 magical peaks. According to the shape of peak forest, it can be divided into five types: peak forest, Jianfeng forest, Qunlong peak forest, Luohan peak forest and overlapping peak forest, with different landscapes. When Xu Xiake traveled to this time in the Ming Dynasty, he could not help but admire: "Li Cong's peak is a thousand miles away, which is a wonderful victory in the southwest."

Water cuts high mountains and deep and steep karst canyons. In the mountainous karst area, rivers and floods constantly scour the rock walls, and finally the mountains give way to water. Just like the Yangtze River, the longest river in China, which runs through the northern and southern Wushan Mountains, it has developed a typical karst landform of high mountains and canyons, which is magnificent and profound, and is known as "majestic, strange, dangerous and beautiful".

The Three Gorges of the Yangtze River starts from Baidicheng, fengjie county, Chongqing in the west and ends in Nanjinguan, Yichang, Hubei in the east. It is known as the "natural gallery" created by nature. Photography/Zheng Yunfeng

Beneath the magnificent mountains and rivers, there is a magnificent underground world. Running water continuously intrudes into carbonate rocks along cracks and caves, and dripping water can penetrate the rocks, so the gurgling water can "eat" these seemingly hard rocks, and underground rivers, caves and stalactites appear?

Geologically, an underground river is defined as a river that sinks below the surface and flows along underground caves and cracks in karst areas. Originally, the flowing water only flows along the tiny cracks in the rock, but with the chemical interaction between water and carbonate, the cracks gradually expand, and finally an underground river is formed over time. Only in China's Guangxi, Guizhou, Yunnan, Sichuan, Hubei, Hunan and other provinces, more than 2,000 underground rivers have been found, winding all the way from the remote southwest to the densely populated central part like a link, bringing abundant groundwater resources.

Du 'an Underground River National Geopark in Guangxi is located in the slope zone of transition from Yunnan-Guizhou Plateau to Guangxi Basin. It has the largest underground river system in the world-Sudi Underground River, with a catchment area of more than 65,438+0,000 square kilometers, which has eroded the stratum and made it intertwined and flowing endlessly underground. During the flood season, it even rushes to the surface to form a seasonal river, and then disappears into the ground at low tide.

Sudi's underground river sometimes emerges from the ground and forms a seasonal river on the ground. Photo courtesy/creativity

Groundwater is continuously mined in carbonate rocks, and the degree of erosion is different because of the different components of the rocks. The water flow will create a cavity where it is particularly easy to dissolve. This is a cave. In China, the number of karst caves can reach hundreds of thousands, and there are more than 20 giant caves with the length exceeding 10 km. Among them, Shuanghe karst cave group in Zunyi, Guizhou is more than 200 kilometers long, and the whole cave length is still under exploration.

With caves, stalactites are not far away. Groundwater dissolves carbonate rocks, and when it drips to the top of the cave, carbonate precipitates and then precipitates, forming various stalactites. Stalagmite, stone pillar, stone curtain, stone bud, bell flag? When they are combined together, different shapes such as "forest", "lion" and "bead curtain" appear, and a magnificent and changeable underground karst landscape is constructed.

Underground rivers, caves and stalactites always appear together, among which stalactites have different shapes. Photography/Li Jin

When the karst cave is constantly eroded, the remaining rock wall can't support the roof of the cave, and collapse follows, giving birth to a spectacular karst landscape-tiankeng. 200 1 geologist Mr. Zhu put forward the concept of "tiankeng"-a karst negative terrain leading from underground to the ground, surrounded by closed steep rock walls, with a plane width and depth of more than 100 meters and a bottom connected with an underground river.

Because the sinkhole is particularly grand, steep and magnificent, it seems to lead to another world deep in the earth at first glance, which makes people unable to restrain their desire to explore. For example, Xiaozhai Tiankeng in Fengjie, Chongqing is 666 meters deep, which is the deepest known Tiankeng in the world. You know, Shanghai Tower, the tallest building in China, is only 632 meters high, which shows the ingenuity of nature.

Standing at the bottom of Xiaozhai tiankeng and looking up, I saw the blue sky like a full moon, which was quite a feeling of "sitting in the well and watching the sky". Photo courtesy/creativity

When the roofs of underground rivers and caves collapse, they sometimes form natural bridges-the two ends of the residual part are connected with the ground, and the middle is suspended to form a bridge. Man built a bridge across the river; Nature builds bridges to let flowing water pass.

Xiangqiao in Luzhai, Liuzhou, Guangxi, is regarded as a model of natural bridge by geologists and included in Karst Dictionary. It spans both banks of the river and is surrounded by green trees. Various forms of stalactites are hung under the bridge. When the breeze swept across the water, Natural Bridge's reflection floated slightly, which witnessed how the mountain was carved into today's beautiful scenery by running water for thousands of years.

The Luojiang River flows endlessly, breaking through mountains and chopping stones, and the Tiansheng Bridge is washed away by its own strength. Photography/Chen Bixin

The flowing water eroded the valleys and sinkholes in the front mountain, creating a three-dimensional landscape, but where will the dissolved carbonate go? Travertine gives us the answer. When the water rich in carbonate overflows, carbon dioxide escapes from the water, and carbonate deposits on the bottom of the water, forming colorful travertine beaches, travertine pools, travertine waterfalls, travertine lakes and so on. They are scattered in Minshan Mountain, Qionglai Mountain, Gongga Mountain, Haba Snow Mountain, Shangri-La and other places in the southwest of China, creating countless fairy secrets.

The famous Jiuzhaigou is one of the representative works of travertine landscape. The Peacock River in Jiuzhaigou is crystal clear and flows through Haizi, large and small. Carbonate is continuously deposited on rocks, water bottom and plants, forming a pool of clear water, which is connected together like strings of beads, and presents different colors because of different microorganisms growing on the surface, which is like a dream.

The travertine in Jiuzhaigou is colorful, turning springs, waterfalls, rivers, beaches and Haizi into colorful jade pots. Photo courtesy/creativity

In addition, karst landforms include karst ditches, shafts, karst depressions, karst valleys, skylights and so on. Nature has created magical landscapes. What interactions have people had with these landscapes?

Between mountains and rivers, poetry is infinite.

In the south of China, nature created karst landforms, people adapted to nature and lived in them, and civilization was born.

In karst areas with overlapping peaks, people live by mountains. It is not as rich as plains and basins. Grain can only be produced by a thin layer of soil in crevices and gravel, and farming is plagued by soil erosion all the year round.

People don't give in to the environment, but work to create a place to live-the limestone mountains unique to karst landforms are all stones, so baskets of soil are carried from the foot of the mountain; Water easily seeps into the ground, so dams are built layer by layer at the edge of the platform to intercept the rainwater on the first-class fields. From Guangxi, Guizhou to Yunnan, mountain terraces have become the most beautiful manufactured landscapes in the continuous mountains, and how many people have been nurtured for thousands of years.

Just like the famous Hani Terrace, it was born in the southeast section of Ailao Mountain in Yunnan. This is a typical karst landform. The Hani epic sings: "Black stones cover the night, and strange boulders become magical towering mountains?" In the process of adapting to the land for hundreds of years, the Hani people have cultivated countless hundreds of "Tian Shan". The terraced fields are layered from the foot of the mountain along the hillside, leading directly to the vast sea of clouds, which is spectacular.

Terrace is actually a great creation that local indigenous people have invested huge manpower, material resources and skills in order to adapt to harsh natural conditions. Photography/Lu Jiangtao

When people living in karst areas can meet the most basic food needs, villages will follow the trend, more people will gather and an ancient town will appear. If the ancient towns in the south of the Yangtze River rise from the water, then the ancient towns in the southwest are often accompanied by mountains.

Huangyao Ancient Town in Hezhou, Guangxi Province was built in the Wanli period of Ming Dynasty, and more than 300 buildings in Ming and Qing Dynasties are still preserved. This is the remnant vein of Nanling Mountains, which is distributed in karst depressions, peak forests and peak clusters, and is a typical karst landform. Because the land is scarce and the things are expensive, and the terrain at the foot of the mountain is narrow and uneven, all of which are stones, Huang Yao people built their houses on stone slopes layer by layer, transforming the unfavorable terrain into a special architectural layout, surrounded by rivers, pavilions and pavilions, and hiding poetry in the secret karst peak forest.

Huangyao ancient town is a typical karst landform. There are many strange peaks in the territory, deep caves, surrounded by Qingxi, and houses gather on stone slopes. Photography/Zhao

In the city of Guilin, the beauty of karst landscape is vividly reflected. Guilin is surrounded by majestic karst peak forests among the peak forests, and there are dozens of isolated mountains in the city, such as Duxiu Peak, Fu Bo, Diecai Mountain, Putuo Mountain, Crescent Mountain, Chuanshan Mountain, Hidden Mountain and Elephant Trunk Mountain. The graceful Lijiang River winds through Feng Wan, and the green mountains and green waters reflect each other, showing the poetry of "the green belt on the left of the river, the mountain is a hairpin" and "a few miles from the Lijiang River, the tip of Guishan is 10,000 points".

The dating of mountains and rivers and cities is inseparable from the role of people. When the Lijiang River, which originated in Maoershan, was filled with sand or even boulders, pieces of flat land dissolved between the peaks, and people from the Central Plains from afar began to build rows of buildings, leaning against the slender peak forests. After the Song Dynasty, Guilin even once became the political, economic and cultural center of Guangxi, known as the "Southwest Huizhou House". The literati came here and left the swan song of "Guilin's landscape is the best in the world". Civilization breeds and spreads in mountains and rivers.

The exploration, running-in and integration of water and mountains have created a magical karst landform. The encounter between people and mountains has given birth to poetry and painting, and endless stories have been brewed for hundreds of millions, thousands and thousands of years. Karst landform came into being here, silently changing the surface, shaping the landscape, influencing and integrating into people's lives.

Nowadays, in Guilin, the streets and alleys are in harmony with the natural landscape of the peak forest, and the battlements are all in the mountains. Photo courtesy/creativity