Chinese name: karstlandform English name: Karst Landform Karst landform definition 1: Soluble rock is the general name of all kinds of eroded and accumulated objects formed on the surface and underground through the processes of water dissolution, erosion, gravity collapse and rock mass collapse. Subject: geography (first-class subject); Geomorphology (two disciplines) definition 2: the landform formed by dissolution and precipitation of soluble rocks, erosion and deposition of groundwater and surface water, gravity collapse, collapse and accumulation. Discipline: resource science and technology (first-class discipline); Resource Geology (two disciplines) This content is approved and published by the National Committee for the Examination and Approval of Scientific and Technical Terminology.
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Karst landform is the general name of surface and underground forms formed by dissolving soluble rocks with water, also known as karst landform. In addition to dissolution, it also includes mechanical erosion processes such as erosion, latent erosion and collapse of running water. The word "karst" comes from the name of the carbonate plateau in the Istra Peninsula in the northwest of the former Yugoslavia, which is called karst locally, meaning the place where rocks are exposed. "Karst landform" is named after the origin of modern karst research.
catalogue
Principles of genetics
Formation conditions of soluble rocks
permeability of rocks
line production
Climate impact
stage of development
Pseudokarst
Study history
Research significance
Geomorphological classification
Distribution of karst landforms on the surface of China.
Underground karst
Famous landscape
Principle of cause of world distribution
Formation conditions of soluble rocks
permeability of rocks
line production
Climate impact
stage of development
Pseudokarst
Study history
Research significance
Geomorphological classification
Distribution of karst landforms on the surface of China.
Underground karst
Famous landscape
The Genesis Principle is an extended edition of this section of world distribution.
Karst landform (3 sheets) Kaka karst landform
The formation of Worcester landform is the result of long-term dissolution of groundwater in limestone area. The main component of limestone is calcium carbonate (CaCO3), which reacts with carbon dioxide in the presence of water to generate calcium bicarbonate [Ca(HCO3)2], which is dissolved in water, thus forming a cavity and gradually expanding. This phenomenon is most typical in the karst plateau along the Adriatic Sea in southern Europe, so this terrain in limestone area is often called karst landform.
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karst landform
Karst landform rock
The basic condition for the formation of karst landforms in soluble rocks is that karst landforms are widely distributed in southwest China, and the most important thing is that there are development subjects. A large number of carbonate rocks, sulfate rocks and halide rocks have formed various peculiar karst landscapes on the surface and underground under the constant dissolution of running water. In terms of solubility, halogenated rocks >: sulfate rocks >: carbonate rocks; Because there are many kinds of carbonate rocks, its solubility depends on the amount of insoluble impurities. Limestone >: dolomite > marl. From the analysis of rock structure, the larger the crystalline rock particles, the smaller the solubility; The solubility of equigranular rocks is worse than that of unequal granular rocks.
permeability of rocks
Rock has certain pores and cracks, which is the main channel of underwater seepage flow.
. The bigger the rock fracture, the stronger the water permeability of the rock and the more obvious the karstification. In karst caves, the stronger the karstification, the larger the karst caves, the more underground pipelines, and the more complete the development of karst landforms, forming an expanding circulation network.
line production
1. Dissolution of running water The solubility of water comes from carbonic acid (H2CO3) formed by the combination of carbon dioxide (CO2) and water. Carbon dioxide is the hero of the formation of karst landforms. Carbon dioxide in water mainly comes from atmospheric flow, corrosion of organic matter in water and mineral weathering. The following chemical equations reflect the development of karst: H2O+CO2 = = H2CO3; (Step 1: Carbonic acid generation) H2CO3 = = H++HCO3-; (Step 2: Carbonic acid dissociates to generate H+) H++CaCO3 = = HCO3-+Ca2+ (Step 3: H+ reacts with CaCO3 to generate HCO3-, thus dissolving CaCO3) These reactions are very complicated in nature, because many natural conditions such as temperature, air pressure, biology, soil and so on restrict the progress of the reactions, and these reactions are reversible, and the carbon dioxide in water increases. The karst process is relatively easy, otherwise it is not conducive to the karst process. 2. The flowing action of running water makes it more erosive. Why? Because the carbon dioxide in water needs to be replenished in time, the dissolution of water can be carried out smoothly and the solubility of water can be consolidated and strengthened. At the same time, the running water drives the gravel at the bottom of the river to mechanically erode the rocks, which is more conducive to the deepening of karst.
Climate impact
For example, in southwest China, the climate is humid, the precipitation is large, the surface runoff is relatively stable, and the infiltration of running water is continuous, and the precipitation effectively updates and supplements the running water. Therefore, karstification can continue.
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1. Surface water dissolves along the joint surface or fracture surface in limestone, forming karst ditch (or karst trough), and limestone originally distributed in layers is divided into stone pillars or stalagmites by karst ditch. 2. Surface water permeates and dissolves downward along limestone cracks, and a sinkhole is formed when the depth exceeds100m. 3. The groundwater falling from the sinkhole flows laterally to the aquifer, forming a karst cave. 4. With the formation of underground caves, the surface collapses, and those with large collapse depth and small area are called collapse funnels, while those with small depth and large area are called collapse ponds. 5. The long-term combination of groundwater dissolution and subsidence has formed inclined valleys and natural bridges. 6. With the rise of the ground, the original caves and underground rivers were taken out of the ground and turned into dry valleys and stone forests, and the dissolution of groundwater continued under the old caves and underground rivers. The stone forest in Lunan, Yunnan Province is the product of the first stage (ditch-dissolving stage), and the natural scenery here is particularly charming because of the touching legend of Ashima girl. Elephant trunk mountain in Guilin was formed when the primitive underground river was exposed to the surface. In Guangxi, you can often see this kind of cave exposed to the surface, commonly known as "fairy mirror" or "fairy mirror".
Edit this fake karst
Phenomena similar to karst in form due to other differences are collectively called pseudo-karst, including clastic karst, loess and clay karst, hot lava karst and lava karst in volcanic rock area. They are not composed of soluble rocks, which are essentially different from karst.
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China's written records of karst phenomena can be traced back to 2,400 years ago. About 300 years ago, Xu Hongzu (knight-errant) had specially studied and described the karst landforms and cave karst landforms in southern China.
. Karst landforms are especially controlled by the geological background dominated by lithology and the geographical environment dominated by climate. Its basic types are divided into carbonate karst, gypsum karst and salt karst according to lithology; According to the existing forms, it can be divided into bare karst, covered karst and buried karst; According to the development degree, it can be divided into total karst, semi-karst or flowing karst; According to the climatic and geomorphological zones, it can be divided into tropical, subtropical, temperate and cold zone karst; According to the vertical dynamic zone, it can be divided into seepage (vadose zone), shallow phreatic (saturated) zone and deep karst zone. The particularity of karst landform is that it has both surface and underground karst forms-caves, which is related to its causes. The main types of karst surface morphology are peak forest, solitary peak, residual hill, karst hill and stone bud. The main types of negative topography are tiankeng, Dou Lin, shaft, blind valley, dry valley, karst depression, Boli valley, karst plain, karst valley (canyon), karst gully and fissure. There are often genetic connections between the positive and negative topography of the surface and between the surface and underground karst types, which constitute a certain geomorphological combination. Karst buttes, residual hills and karst plains often form a combination type. Karst shaft is a vertical channel for hydraulic connection between surface sinkhole and underground karst system. Karst landform is the product of long-term development, and its evolution model is influenced by erosion cycle theory, from the early A.Grund to karst landform.
The recent models of L.Jakucs and P.W.Williams are basically qualitative 3-4 stages. Since D.I.Smith put forward the mathematical model of the evolution of exogenous karst landform in 1972, the mathematical model of karst landform development and dynamic and morphological factors by mathematical methods is developing. For example, W.B.White put forward a process model of karst terrain development rate in 1988. Global carbonate rocks account for 1 1% of continental crust. China has only bare karst, that is, more than 900,000 kilometers, which is the country with the widest distribution and the most complete types of karst. Due to the special karst landform, the problems of regional economic development and engineering construction are also very prominent. For example, a dry valley is a kind of leaky valley, which turns a surface river into an underground river due to the erosion of the basement and the drop of groundwater level. In hydraulics, it is classified as suspended valley, which is generally not suitable for building reservoirs. Even if the reservoir is built, anti-seepage measures such as blanket and curtain grouting should be taken. Karst landform has become a tourist resource because of its peculiar shape, underground caves and the characteristics and beneficial components of air and water in some caves. For example, Guilin landscape in China and Lunan Stone Forest in Yunnan.
The research significance of editing this paragraph
Karst research has important theoretical and practical significance. There are many unfavorable factors to be overcome and prevented in karst areas, and there are also many favorable factors to be developed and utilized. When selecting a reservoir, we should try to avoid faults, fracture zones and karst landforms. Karst mineral springs and hot springs are rich in beneficial elements and gas and have medical value. Karst caves and ancient karst surfaces are rich in sedimentary minerals, and ancient karst buried hill is a good oil and gas reservoir structure. The grotesque caves in karst areas, rivers with alternating light and dark, and clear karst springs are all good tourism resources. For example, Jiutian Cave in Sangzhi County, Zhangjiajie, Hunan Province has been listed as the first cave in Asia, and Huanglong Cave has been listed as a part of Wulingyuan in Zhangjiajie, a world natural heritage, a world geological park and the first batch of national 5A tourist areas. It is the topographic representative of underground karst in Zhangjiajie, in which karst landforms account for about 40% of the city's area. Guilin landscape in Guangxi and Lunan Stone Forest in Yunnan are famous at home and abroad. Because of its unique geomorphological characteristics, karst landforms are often easy to "produce" different types of scenic spots. For example, the Dragon Palace and Zhijin Cave in Guizhou.
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According to the exposure conditions, karst landforms can be divided into four types: bare karst, covered karst and buried karst. According to climatic zones, it can be divided into five types: tropical karst, subtropical karst, temperate karst, cold karst and arid karst. According to lithology, it can be divided into four types: limestone karst, dolomite karst, gypsum karst and salt karst. In addition, there are different divisions according to altitude, development degree, hydrological characteristics and formation period.
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Surface karst landform
1. Karst gullies and stone bud karst gullies refer to rock grooves formed by the continuous erosion and erosion of surface water along rock surfaces and cracks; Stone bud refers to the protruding stone ridge between gullies, which is actually the residue during the formation of gullies. Yunnan Shilin is a well-developed tall stone bud group, and its formation conditions are thick layer, pure quality, gentle occurrence, sparse vertical joints and humid climate and environment. 2. Tiankeng and shaft are mainly due to the continuous depression of karst ground, forming funnel-shaped circular depressions or shaft-shaped holes, which are widely distributed in Chongqing and southern Sichuan. They are formed on both sides of steep slopes, depressions and the bottom of basins. Due to the strong erosion of running water along the cracks in rocks, tiankeng or shaft is tens to hundreds of meters deep. 3. Karst depression and karst valley karst depression is a kind of closed karst depression, with a wide range and approximate circle, surrounded by many low mountains and peak forests, with a flat bottom, which is prone to waterlogging in rainy season and drought in dry season. The area ranges from half a square kilometer to more than ten square kilometers. The dissolution valley is formed by the further expansion or integration of the dissolution depression, which is greatly influenced by the structure and has a wide area. Generally, it is tens of square kilometers to hundreds of square kilometers, distributed in a plane strip, dozens of kilometers long and flat at the bottom. For example, there is a dissolved valley in Duan, Guangxi, which is one kilometer wide and ten kilometers long. This karst terrain is widely distributed in Yunnan-Guizhou Plateau in China, and the locals call it "bazi". 4. Dry valley Dry valley is a valley left over from the disappearance of surface runoff in karst area, which is formed by a certain section of river flowing into the ground along the shaft or water conveyance tunnel at the bottom of the river to form underground runoff. This phenomenon that surface runoff becomes underground runoff is called undercurrent. Another reason is the result of river cutting and straightening. This landform type is common in North China and Northeast China. 5. Peak forest, peak cluster, solitary peak and Tianshengqiao "Guilin Stone Forest"
Landscape is the best in the world, and Yangshuo landscape is the best in the world. "China and Guangxi have unique scenery, and karst is the main reason for this natural barrier. Peak cluster is a collection of peaks formed by strong dissolution of soluble rocks. Peak forest is formed by the further evolution of peak cluster. Of course, under the action of neotectonic movement, the peak forest will be transformed into peak cluster with the rise of the crust. The peak is pointed like a cone, tower and column, with stone buds and karst ditches on the surface, and there are often caves and shafts between the peaks. The peak cluster landform can be said to be a museum of karst landform. Gu Feng is an isolated limestone peak in karst area, which needs long-term stability of the earth's crust without much geological movement. The strange and beautiful scenery of Guilin will tell you your love for nature. Tianshengqiao is an arched landform formed by the dissolution of the lower part of soluble rock by running water. 6. Surface travertine accumulation This is a typical surface karst landform, mainly including waterfall travertine, travertine dam and karst spring travertine. Waterfall bloom refers to the sudden increase of water velocity, decrease of internal force, and the escape of carbon dioxide in the water, forming waterfall bloom. The famous Huangguoshu Waterfall in Guizhou, China belongs to this kind. The formation of travertine dam is that the alpine snow and ice dissolved water containing a lot of CaCO3 and the underground seepage karst water containing a lot of CaCO3, after a certain distance of underground runoff, are discharged from the surface in the form of spring water. With the increase of water temperature, the acceleration of water flow speed and the action of a large number of algae, a large number of travertine deposits are formed. Travertine contains many impurities and many different elements, and is influenced by aquatic plants, which makes travertine show many colors. This landform is widely distributed in the first generation Huanglong Temple in Sichuan, China, and the development of tourism in Huanglong Temple is closely related to this unique karst landform. Karst spring flower is a kind of spring water, in which a large amount of CaCO3 is dissolved and gushes out from the surface. Due to the increase of temperature and the decrease of pressure, CaCO3 forms travertine deposits at the spring mouth, and the long-term accumulation makes the spring flowers form different shapes, which is also a beautiful scenery endowed by nature to human beings. This karst landform is very common in Yunnan, China.
Underground karst
1. Overview of karst caves. Karst cave is an underground cave formed by the dissolution and expansion of groundwater along the cracks of soluble rocks. They come in different sizes and can accommodate more than 1000 people. Caves of various shapes
Strange, there are many strange landscapes in the cave, such as stalagmites, stone pillars, stalactites and stone curtains. It's too small to pass a person. Caves are the result of water dissolution, flowing water erosion and gravity for a long time. The karst cave landscape-Xuehua Cave in Fuxi Mountain (15) is widely distributed in Hunan, Sichuan, Guizhou, Yunnan, Guangxi and other provinces in China. 2. Dissolution landform-Stone pot and side trough If a local place at the top of the cave is subjected to strong turbulence, with the increase of water pressure, the dissolution capacity of these places is greater than that of the surrounding area, thus forming a cambered surface concave to the top. This landform is called stone pot. Side ditch refers to the trough-shaped landform in which the side wall of karst cave forms a cave-oriented depression under the action of water solution. These two karst landforms are very common in karst caves. 3. Accumulation landform: underground dissolved rock accumulation landform
It is the essence of cave landscape, and you can enjoy the magical cave world in the caves in southwest China. The accumulation of gravity water is the main formation mode of karst cave accumulation landform. Water drops with a large number of soluble rocks fall intermittently from the top of the cave and accumulate continuously, thus forming colorful stalactites, stalagmites, stone pillars, stone curtains, marginal stone dikes and so on. Stalactite is an inverted cone-shaped karst deposit, which can reach several meters in size and only a few centimeters in size. It is mainly caused by karst water seeping out along the tiny cracks at the top of the cave and continuously precipitating at the dripping place. It is closely connected with the top of the cave and extends to the bottom of the cave. Stalagmite is a karst deposit extending upward from the bottom of the cave, which is mainly the product of continuous deposition of karst water dripping to the bottom of the cave. Compared with stalactites, it generally appears in the form of bamboo shoots, towers and cones. The cross sections of stalactites and stalagmites are concentric circles. Stalactites and stalagmites grow relatively and gradually combine into a whole. With the continuous deposition of karst water, they gradually form thick stone pillars. Stone curtain is the product of CaCO3 _ 3 gradually deposited in the process of karst water flowing along the cave wall in the form of thin film. It is generally flaky and layered, with curved streamline and tens of meters high, which is very spectacular. Edge stone wall refers to the rock wall-like deposits on both sides of the bottom of the cave, which are several centimeters to several tens of centimeters high, arc-shaped and stepped. In addition, there are many grotesque landscapes in the cave, some like lotus flowers, some like branches stretching, and some stone grapes, stone corals and so on.
Famous landscape
Karst landforms are widely distributed in China, and the creator carved many karst landforms for Chinese children.
Natural barriers and karst landforms bring infinite vitality to tourism in China. There are various types of karst landforms in China, which are valuable wealth for scientific research. Distribution of famous karst scenic spots in China: Guangdong: Seven limestone peaks in Qixingyan, Zhaoqing are shaped like the Big Dipper, and there are many caves in front of them. There are many underground rivers and various strange caves in the cave. Guangxi: Guilin's landscape and Yangshuo scenery are mainly famous for the karst landform on the surface, such as stone buds, stone forests, peak forests and Tiansheng Bridge. There are holes in the mountains, and it is "surprising that there are no holes". The cave landscape in Ludi, which is dominated by cave landforms, has all kinds of grotesque cave accumulation landforms, forming the cave spectacle of "Lian Bi Jade Bamboo Shoots"; The underground corridor composed of stalactites in Qixingyan is really beautiful; Wuming Yiling Rock, Beiliu Gulou, Liuzhou Duleyan, Xingping Lotus Rock, Xing 'an Rudong, Yongfu Baishouyan, Yishan Bailong Cave, Lingyun Water Source Cave and Longzhou Xiazi Cave are also famous karst cave scenic areas. Yunnan Lunan Stone Forest Scenic Area: Linqibu, the surface peak, is mainly a huge stone bud landscape. Most limestone peaks are distributed on both sides of the valley. All kinds of stone peaks are lifelike, lifelike. Among the 35 stone forests in China, there are 20 stone forests in this province, such as Lunanda Stone Forest, Xiaoshi Stone Forest, Naigu Stone Forest, Hemo Stone Forest, Shibanshao Stone Forest and Tianshengqiao, which shows that the stone forests in this province are widely distributed. Cave landscapes include Yuxi Cave, Jianshui Yanzi Cave and Jiuxiang Cave. Stone Forest Landscape (20 photos) Guizhou: There are stone forest areas such as Xingyi Hanni Stone Forest and Xiuwen Stone Forest in this province; Huangguoshu Waterfall is the largest waterfall in China with waterfall-like landforms. There are many local caves, including Longgong Cave near Huangguoshu Waterfall, Guiyang Underground Park, Zhenning Rhino Cave, Zhenyuan Qinglong Cave, Longshan Fairy Cave, Guizhou Zhijin Cave and Qianling Mountain Qilin Cave. Sichuan: Jiuzhaigou travertine belongs to underwater surface accumulation landform, such as Pearl Beach Waterfall; The calcified pools, calcified slopes and calcified caves in Huanglong Scenic Area constitute the largest and most beautiful karst landscape in the world. The Xinshi Arch Bridge in Shizhu County is a karst natural bridge landform. Hunan: Huanglong Cave in Wulingyuan and Boyue Cave in Lengshuijiang are grotesque cave landscapes, and various piled landforms are listed among them, such as Shenxianfu Cave, which is mysterious. Jiangxi: There are caves all over the cliffs of Shi Zhongshan Scenic Area in Poyang Lake Mouth; The Longgong Cave in Pengze is 2000 meters long and can be seen by boating. It is called "Underground Art Palace". Zhejiang: Yaolin Wonderland, located in Tonglu County, is a large-scale and magnificent karst cave tourist resort in Zhejiang Province and the largest cave discovered in Zhejiang today. The length of the cave is 1000 meters, and it is * * six holes, which is famous for its "male, strange, beautiful and deep". Jiangsu: Yixing limestone cave has the reputation of "cave world". Shanjuan Cave, Zhanggong Cave Cave and Guling Cave are also called "three wonders". The caves are deep and full of stones, with many strange stones and columns, among which boating is like entering the Dragon Palace under the sea. Jilin: Tonghua Yayuan Cave has four halls. The cave is full of stone pillars, stalagmites, stalactites, stone waterfalls, stone curtains, lotus flowers, stone curtains and other piled landscapes. There is a karst pool in the depth, which is unfathomable and inaccessible. These places can be used for sightseeing and scientific research. They are the pearl of tourism and the treasure house of scientific research.
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The Dinara Mountains in Yugoslavia, the Central Plateau in France, the Urals Mountains in the Soviet Union, southern Australia, Kentucky and Indiana in the United States, Cuba, Jamaica and northern Vietnam.