Why did the Taihang Mountains, thousands of miles away, only have "Eight Strings of Taihang Mountain" in ancient times, and there were beautiful scenery everywhere?

Modern tourists walk into every canyon in Taihang Mountain, and on the cliff at the end of the valley, they will see a "waterfall" landscape with a drop of 2-3 meters. For the ancients, all the waterfalls in these valleys are insurmountable traffic obstacles. Most of the ancient roads crossing Taihang Mountain suffer from this huge cliff, and the only ancient road in Bajiao is also difficult.

Taihang Mountain is located in the middle of China, between Shanxi Plateau and North China Plain, and spans four provinces and cities of Beijing, Hebei, Shanxi and Henan. It starts from Xishan in Beijing in the north and extends to Wangwu Mountain at the junction of Henan and Shanxi in the south. It runs for more than 8 miles in the northeast-southwest direction, and is known as "Taihang Mountain in 8 Li", which is the geographical boundary between North China Plain and Loess Plateau and the third step of China.

Taihang Mountain is high in the north and low in the south, and most of it is over 12m above sea level. The mountain is steep in the east and gentle in the west. The west wing connects the Shanxi Plateau, and the east wing is like a huge wall rising from the ground, standing in the west and north of the North China Plain in Ma Pingchuan.

1. Why are there "shadows of Yuntai Mountain" everywhere in Taihang Mountain area

People who have traveled to Yuntai Mountain will find a magical phenomenon, that is, after traveling to Yuntai Mountain in Jiaozuo, Henan, and then visiting other scenic spots in Taihang Mountain area, whether in Henan, Hebei or Shanxi, you can see "shadows of Yuntai Mountain" everywhere-red canyons, long cliffs and strange ones. Geologists tell us that this ubiquitous landform in Taihang Mountain area is called "Yuntai landform", which is the most representative landform in Taihang Mountain area.

Yuntai landform generally refers to the combined landform with layered clastic rocks and carbonate rocks distributed in Taihang Mountain and Yanshan Mountain, with valley walls like walls, terraces like ladders and angular peaks. The formation of Yuntai landform has its special tectonic background, rock assemblage, climatic conditions, hydrodynamic factors and geological evolution process.

The landscape of Yuntai, with valleys in rows, valley walls like walls, cliffs like ladders and angular peaks, is a representative landform type in the South Taihang area. Due to the strong uplift of the Taihang Mountain fault block (Shanxi Plateau) and the strong depression of the North China Plain, during the confluence of many rivers from the Shanxi Plateau to the North China Plain, the hydrodynamic action strongly cuts down the mountain, forming many canyons with high mountains and deep valleys and splashing waterfalls.

Because most places in Taihang Mountain area have similar stratigraphic structure with Yuntai Mountain, and the mountain landform also has similar formation background, "Yuntai landform" has strong universality in the whole Taihang Mountain area. No wonder we can see the "shadow of Yuntai Mountain" everywhere in Taihang Mountain.

Second, the typical "three sets of strata" structural landscape in Taihang Mountain area

According to the lithologic characteristics, there are three sets of strata in Taihang Mountain area. These three sets of different lithologic characteristics have created a multi-step landform landscape with both male and female features in Taihang Mountain area.

The oldest rock at the base of the mountain in Taihang Mountain area is Archean metamorphic basement, which can be traced back to Archean 2.5 billion years ago. This is an ancient granite gneiss, and the landform often forms a slope landform with a high angle between the piedmont and the valley bottom.

On top of the ancient metamorphic rocks are Mesoproterozoic purplish red Shi Ying sandstones. These purplish red Shi Ying sandstones were deposited in the coastal zone of Mesoproterozoic 1.4 billion years ago. The various wave marks and mud cracks on the rocks are the portrayal of the geological environment at that time. The numerous Hongshi canyons in Taihang Mountain area are the masterpieces of this set of rocks. Huge steep cliffs in the middle and lower part of the mountain are often formed on the landform.

The overlying strata of quartz sandstone are Paleozoic carbonate rocks, which were formed in Cambrian-Middle Ordovician over 5.4 billion years ago. At that time, it was a typical land surface sea environment. It is a type of ancient ocean that has disappeared now. The warm sea water is shallow and turbulent, which is very conducive to biological growth and carbonate deposition. Therefore, trilobites can be found in these strata, and trilobites were a kind of paleontology at that time. Geomorphologically, this set of rock strata often forms the first-class gentle slope and giant steep cliff in the middle and upper part of the mountain.

after the formation of the above-mentioned rock strata, the region has experienced many stages of tectonic movement, and as a result of tectonic movement, many groups of grand and vertical structural joints have been produced in these rock strata, which have become the guiding factors for the formation and evolution of canyon groups in Taihang Mountain area.

iv. Taihang Mountain with numerous canyons and huge waterfalls

The huge contrast between Taihang Mountain and North China Plain makes many rivers trace the existing groups of grand and vertical structural joints in the process of flowing from the hinterland of Taihang Mountain to North China Plain, and strongly undercuts Taihang Mountain, forming numerous canyon groups with high mountains and deep valleys and splashing waterfalls. Deep in the canyon, due to the special geographical location and stratigraphic structure, a series of tributaries originating from the hinterland of Taihang Mountain cut through the Taihang peak ridge, forming many secondary canyons, gullies, rapids, waterfalls, deep pools and springs. Adding beautiful beauty to Taihang Mountain.

under the control of stratigraphic structure combination and ancient landform, under the general pattern of stepped landform of Taihang Mountain, two-stage giant cliffs have been formed in the middle of many valleys, that is, in the abdomen of Taihang Mountain, creating numerous waterfalls with a height of 1-3 meters in Taihang Mountain area.

these two huge geomorphic cliffs are the first cliff landscape with Mesoproterozoic purplish red Shi Ying sandstone as the main body (some areas are CAMBRIAN carbonate strata) under the control of the planation plane in Tangxian period, which is generally located in front of Taihang Mountain or several thousand meters in front of Taihang Mountain, and the geomorphic landscape is dominated by cliffs and U-shaped canyons. The second cliff landscape is located near the main ridge in the hinterland of Taihang Mountain, which is dominated by Ordovician and CAMBRIAN carbonate strata under the control of the Taihang planation plane. The landform is dominated by the formation of carbonate cliff and barrier valley, and the height of many cliffs can reach up to 3-5 meters.

5. Why did the Taihang Mountains in ancient times only have the word "Taihang Eight Dragons"?

Dragonflies (sound xíng) which means the place where the mountains are interrupted, and it also means the gap in the mountains. People searched along the gap and found the way across the mountains.

Taihang Mountain, as the natural boundary between Shanxi Plateau and North China Plain in China, has a terrain difference of 1,-2, meters, which has become a natural barrier for communication between them, and is called "the ridge of the world" by historical geographers. The steep Taihang Mountain is like a barrier, which isolates the cultural exchanges between the Loess Plateau and the North China Plain, the two cradles of civilization, and also blocks the material exchanges. However, the numerous fault zones produced when the mountains are uplifted break the barriers and form a passage through these obstacles.

Throughout the ages, from the bank of the Yellow River at the southern end of Taihang Mountain to the foot of Yanshan Mountain in the north, there are Jiguan, Taihang, Baike, Jikou, Jingxing, Flying Fox, Puyin and Jundu. From south to north, the Taihang Eight Dragons crossed the Taihang Mountain in their own similar forms, becoming eight throat passages that ran through the ancient Shanxi, Hebei and Henan provinces and crossed the Taihang Mountain, which was an important military pass on the border between the three provinces. On the main road between Shanxi Plateau and North China Plain, many thrilling stories in China calendar have been staged in these narrow valleys in turn.

In the Eight Hills of Taihang Mountain, except for the natural passage between Wangwu Mountain and Zhongtiaoshan, which are located at the southernmost tip of Taihang Mountain, the rest pass through the valleys of Taihang Mountain. The iron law of water flowing downwards determines that the water on the Shanxi Plateau will eventually flow to the North China Plain, where the terrain is very different. It is these countless currents that originated in the Shanxi Plateau that have created thousands of valleys and valleys on the Taihang Mountains. However, in fact, all these valleys and valleys can't be the ideal natural passage between Shanxi Plateau and North China Plain. As mentioned earlier, the unique stratum structure in Taihang Mountain area not only creates the beautiful terrace and layered landform of Yuntai, but also creates the cliff horizon and huge waterfall landscape visible in the ravine, which becomes an insurmountable natural barrier for human natural passage in the ravine, under the huge terrain difference between the Taihang planation and the Tangxian period, and between the Tangxian period and the modern piedmont plain.

In fact, although most of the Eight Dragons in Taihang Mountain walk along the canyons, they do not walk along the valleys. In order to avoid natural disasters such as floods, these ancient roads mainly walk along some relatively gentle slopes in the valleys formed by mainstream valleys. The corresponding stratigraphic and geomorphological positions of these ideal zones are roughly as follows: the piedmont is generally selected in the hilly area or the gentle slope zone formed by Archean metamorphic rocks-on the flat surface of Tangxian disc-shaped wide valley formed between the top surface of Proterozoic purplish red Shi Ying sandstone and purplish red mudstone of lower Cambrian Mantou Formation, or on the gentle slope formed by purplish red shale of Mantou Formation-on the gentle slope formed by Jiawang shale between Cambrian and Ordovician-on the flat surface of Taihang period or modern mountaintop formed by Ordovician and Carboniferous.

Although these special horizons provide natural conditions for the formation of the Taihang Eight Dragonflies. However, the adjacent surfaces of these special layered surfaces often exist in the form of stepped or high-angle steep slopes, especially between the two large planation planes, namely, the top of the mountain in the middle mountain area of Taihang Mountain (the planation plane in Taihang Mountain) and the foothills of the foothills or the wide-disc-shaped valley surface (the planation plane in Tangxian County), and between the wide-disc-shaped valley surface in Tangxian County and the modern and floodplain landforms, a precipice or wavy steep slope of 3-5m is formed.

a popular metaphor for this landform structure combination is that the top is quasi-plain in Taihang period, and a "wide disc valley" is formed below it, and a "U" valley is formed downwards in the "wide disc valley", and a "V" valley is formed downwards at the bottom of the "U" valley.

Therefore, in order to realize the communication between Shanxi Plateau and North China Plain, even in some deep-cut canyons, we still have to face the obstacles of the valley walls of "V" valley, "U" valley bottom and "disc wide valley". These three kinds of valley walls often appear as vertical or nearly vertical cliffs, and all roads can only come to an abrupt end under the cliffs, sighing at the cliffs.

Most modern tourists can see the heroic image of the "Taihang Waterfall" here, because there is a "waterfall" waiting for you on the cliff at the end of all these valleys, although some possible waterfalls are just a flash in the pan after the rain. Why are the huge waterfalls in Taihang Mountain area again and again thanks to these cliffs? For the ancients, all the waterfalls in the valleys were an insurmountable obstacle. For modern tourists, these insurmountable obstacles of the ancients may be a secret place of modern beauty.

In the face of these precipices, the ancients found some relatively low and gentle areas in some areas with relatively developed fractures in their long-term life, so there were "Yangchangban Road" and "Eighteen Plates" which were common in almost all "Eight Strings in Taihang", and this zigzag winding path with a large angle became the only way for the ancients to cross the above-mentioned precipices. Cao Cao's song "A Bitter Cold Journey" shows that it is not easy to climb the "Yangchangban Road".

This landform structure is the main reason why there were only "Eight Dragons in Taihang Mountain" in ancient times.

Yugong Yishan and the Wall-hanging Highway

It seems that the ancestors living in Taihang Mountain area have been blocked by mountains for generations, and their lives are inconvenient. An allegorical essay "Yugong Yishan" written by Liezi, a thinker in the Warring States Period, is the earliest portrayal of this situation.

"Yugong Yishan" is about an old man who lived in Beishan in ancient times. His name was Beishan Yugong. Two mountains, Taihang Mountain and Wangwu Mountain Mountain, blocked his way out, and he had to take a long detour to get out and in. Later, Yu Gong made up his mind to lead his sons to dig these two mountains with hoes. The article narrates the story of Yugong's dauntless and persistent efforts to dig mountains, and finally moved the Emperor of Heaven and moved the mountains away. This story shows the inconvenience of traffic in Taihang Mountain area. However, Yugong's spirit of "making up his mind, not afraid of sacrifice, overcoming all difficulties and striving for victory" has become a persistent model of labor.

Today, people living in Taihang Mountain seem to have this nature of breaking the mountain and breaking the wall in their bones. In order to change the barrier of this mountain, the reality of "Yugong moving mountains" does not necessarily exist. Modern engineering equipment has dug a series of traffic avenues in Taihang Mountain area. Even in the 196s and 197s, when the technical equipment was not very advanced, a wall-hanging highway was left on the cliffs of Taihang Mountain to prove this miracle.

This article is purely a personal opinion. If there is anything wrong, please criticize and correct me.

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Author: Zhang Bingchen, Deputy Secretary General of china tourism association Geo-tourism Branch, Chief Expert of Henan Geological Survey Institute, Professor-level Senior Engineer, Founder of Geo-science Tourism Window from the media, from Qinyang City, Henan Province. He has presided over or participated in the declaration and construction of dozens of geological parks and mine parks of different levels; Editor-in-chief published Mangshan Loess Characteristics and Regional Comparative Study, Research on the Controlling Effect of East Asian Rift on the Formation of Yuntai Geomorphology, Zhengzhou Yellow River Scientific Guide, Wangwu Mountain Scientific Guide, Yuntai Mountain Scientific Guide, Taking You to Henan Geopark, and participated in the publication of more than 1 monographs such as Geological Relics Resources in Henan Province and Proterozoic Geological Research in Wangwu Mountain, China and its Adjacent Areas.