Carved for billions of years: the natural legend of Zhangshiyan landform

Author: Associate Researcher Zhang Wen

Institute of Geology, Chinese Academy of Geological Sciences

Image: Photographed by the project "Special Geological Mapping of Zanhuang Area in North China Block"

As a geological wonder with a profound history and unique form, Zhangshiyan landform has attracted more and more attention from geologists and travel enthusiasts in recent years. It can be found in Taihang Mountains, Zhongtiao Mountains and other places, but it is particularly prominent in Hebei, Shanxi and Henan. Among them, the Zhangshiyan Scenic Area in Zanhuang County is located in the northwest of Zanhuang County. It has been a famous mountain resort since ancient times and has gathered rich historical and cultural relics. According to historical records, residents had settled here as early as the Spring and Autumn Period and the Warring States Period. In the Sui and Tang Dynasties, it gradually became an important place for Taoist practice, and many Taoist temples stood here. At the turn of the Ming and Qing Dynasties, literati and poets visited here and left behind a wealth of poems and inscriptions. The natural landscape pattern of "three stacks leading nine sets, four screens hiding eight scenes" on the landform makes it the best representative of Zhangshiyan landform. However, how was such a landform formed? What kind of age characteristics and causes are hidden behind it? The following content will show you the secrets of Zhangshiyan.

The rocks in the Zhangshiyan landform are mainly composed of thin layers of sandstone and shale that are easily weathered. These rocks contain hundreds of millions of years of geological history. In the long river of geological time, they have experienced countless crustal movements, climate changes, and other external factors, gradually carving out the unique landforms we see today.

The rock formation structure of Zhangshiyan is distinct and can be divided into three parts. The bottom is the Proterozoic Gantaohe Group, which is mainly composed of metamorphic sodium Changanshan rock and metamorphic diabase and diorite intruded along the layer, which together constitute the basement of Zhangshiyan. The middle layer is the Changzhougou Formation and Zhaojiazhuang Formation of the Great Wall System, which are mainly composed of quartz sandstone, mudstone, etc., with a thickness of more than 400 meters, and are the main part of the Zhangshiyan landform. The upper layer is the Cambrian rock layer, which is composed of shale, limestone and other rocks. These rock layers are generally slightly tilted to the west. Combined with these rocks, the Zhangshiyan landform has gone through four stages of development, from infancy to old age, and a complete development cycle takes about 2.947 million years. The landform we are currently seeing is the result of the landform evolution at different stages in this series of periods.

The formation of Zhangshiyan can be traced back to geological movements, especially the Yanshan Movement, which brought about a strong crustal uplift in the Zhangshiyan area, accompanied by a large number of fractures and folds. These geological changes provided favorable conditions for subsequent weathering and erosion.

The climate characteristic of the north - little rainfall - also affected the formation of Zhangshiyan to a certain extent. Although the upper limestone in the area was not subjected to strong leaching erosion, the quartz sandstone underwent severe erosion, stripping and collapse during certain heavy rainfall events, which led to the gully landforms that can be seen today.

The rocks of Zhangshiyan landform, especially sandstone and shale, are more susceptible to external factors due to their unique physical properties. Under long-term weathering and erosion, they are gradually shaped into sharp rock pillars, deep grooves and continuous cliffs. In addition, external factors such as groundwater activity, biological action, and even earthquakes have also shaped the shape of Zhangshiyan to varying degrees.

In summary, the Zhangshiyan landform is a magnificent epic in nature, which bears the imprint of geological history and witnesses the ingenuity of nature. In order to cherish and protect this unique geological heritage, we should further strengthen its research and protection, pass on the stories behind it, and let more people feel its charm.