600 million years ago, Taihang Mountain was an area of Wang Yang. Later, the earth's crust moved frequently, the ground fluctuated and the sea advanced and retreated. At the time of regression, swamps were widely distributed here, the climate was warm and humid, and dense forests were growing, thus forming rich coal resources in Taihang Mountain. Subsequent crustal activity gradually uplifted Taihang Mountain. Later, it broke with the East-West Great Plain of North China, forming a landform with steep Taihang in the east and gentle Taihang in the west. [2]

Wang Mang Richie Haiyun

About 2.4 million years ago, it began to rise greatly and gradually formed. As early as 2.8 billion years ago, Taihang Mountain area was submerged by seawater, and huge thick clastic rocks, iron-bearing siliceous rocks and carbonate rocks were deposited. Affected by Wutai Movement and Lvliang Movement, the paleostrata in this area generally suffered from fold metamorphism, accompanied by the intrusion of faults and quartzite veins. Until/kloc-0.8 billion years ago, migmatized crystalline basement rocks were formed. [3]

Since the Lvliang Movement1800 million years ago, the crust in this area has entered a stage of differential rise and fall, which led to the advance and retreat of seawater, forming the sedimentary cover of Mesoproterozoic platform and the overlying Cambrian, Ordovician, Carboniferous and Permian strata. Ordovician and Permian are coal-bearing strata. The Mesozoic Yanshan movement gradually formed the Taihang Neocathaysian fold belt and developed the Taihang piedmont deep fault zone. [3]

The Himalayan movement in Cenozoic caused the Taihang Mountain to rise strongly, and the North China Plain in front of the mountain sank relatively. After millions of years of tempering, Taihang Mountain has finally formed. [3]

This area is cut by Juma River, Hutuo River, Zhanghe River, Qinhe River and Danhe River. And there are many horizontal valleys. The local ancient name is "Taihang Mountain Eight Dragons", which is an important tunnel for east-west traffic. Jingxing, Lincheng, Fengfeng, Liuhegou and other famous coal mines are distributed in the fault basin in the east wing of Taihang Mountain. Taihang Mountain is an important geographical dividing line, with the Loess Plateau in the west and the Huanghuaihai Plain in the east. The mountainous area has an obvious blocking effect on the summer monsoon, and there is more precipitation on the windward slope, forming a rainstorm area. On the east side of the mountain is a strong seismic activity zone. [4]

Taihang Mountains

The geological basement of Taihang Mountain is a composite monoclinal fold. The east side is a fault structure with a relative height difference of1500 ~ 2000m. Typical alluvial fans and alluvial plains are developed in front of the mountain. From north to south, there are Xiaowutai Mountain (2882 meters above sea level), Taibai Mountain, Baishi Mountain, Langya Mountain, Nantuo Mountain, Yangqu Mountain, Wangmang Ridge and other peaks. Rivers in the eastern part of Shanxi Plateau pass through Taihang Mountain and enter Hebei Plain, where they join the Haihe River system. Only the Qinhe River system in the southwest flows southward into the Yellow River. [ 1]

Taihang Mountain is an important geographical dividing line in eastern China. The North China Plain in the east is a deciduous broad-leaved forest belt, and the Loess Plateau in the west is a forest grassland belt and an arid grassland belt. There are also obvious differences in the characteristics of vegetation and soil vertical zones on both sides. [ 1]

There are many east-west valleys in Taihang Mountain range, which have been traffic arteries and business travel arteries since ancient times. In ancient times, there was a famous "Taihang Eight Dragons". [ 1]

Taihang Mountain is high in the north and low in the south, with most of the elevation above 1200m. The peaks over 2000 meters are Xiaowutai Mountain, Lingshan Mountain, Dongling Mountain and Baishi Mountain in Hebei, Taibai Weishan Mountain, Sonan Mountain and Yangqu Mountain in Shanxi. The highest peak at the northern end is Xiaowutai Mountain, with an altitude of 2,882 meters. Nanfeng is Fozi Mountain and Mid-level Mountain in Lingchuan, with elevations of 1745 m and 179 1 m respectively. [5]

Taihang Mountain is steep in the east and slow in the west. Rivers in the east of Shanxi Plateau cross Taihang Mountain and enter Hebei Plain, where they join the Haihe River system. Only the Qinhe River system in the southwest flows southward into the Yellow River. [5][6]

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Geological scenery picture of Taihang Mountain

The west wing of Taihang Mountain is connected with Shanxi Plateau, and the east wing is transformed from Zhongshan and low hills to plain. There are many Xiongguan in the mountains, such as Zijingguan in Hebei, Niangziguan in Shanxi, Hongtiguan, Huguan and Tianjingguan. [5]

Taihang Mountain is the natural dividing line between Loess Plateau and North China Plain. Shen Kuo, an outstanding scientist in the Northern Song Dynasty, saw that between the cliffs of Taihang Mountain, "those who are afraid of resisting snails have shell stones like birds' eggs and stone walls like belts". After studying, he pointed out: "This is the seaside in the past, which is nearly a thousand miles away from the sea in the east. "Modern geological research confirmed his assertion. Snail shells between cliffs in Taihang Mountain are brachiopod or mollusk fossils in Paleozoic strata. [3