Decrypting the Causes of Enshi Secret Realm

Enshi Gexin Valley Scenic Area is located in Gaoping Town, Jianshi County. The upstream is connected with the Erhe River, flowing through the junction of the Yesan River, Maorong River and the three rivers, flowing southeast, with a total length of about 3.5 kilometers.

The basin of the Geocentric Valley Scenic Area in Enshi is a low mountainous area of tectonic erosion and erosion in southwestern Hubei. Abundant precipitation produces a typical canyon landform formed by strong river water deep into limestone and dolomitic limestone. The upright rock walls on both sides of the canyon are 100 200m higher than the water surface. The valley walls are sandwiched by high mountains and the cliffs stand up. The distance between the two walls is several meters to tens of meters. The water surface is several meters wide and less than one meter in some parts.

Surface water is developed in the trough valley, and fissure water and dissolved water are developed on the rock wall, and the surface water is supplied all the year round. The canyon is uniform in width, linear extension and stable in shape. Walking on the plank road, in the mist, looking at the canyon from afar, it is narrow and deep, with lush vine branches and long hanging down, and the rumbling sound of running water is endless. Accompanied by the chirping of birds and insects, the scene is amazing and unforgettable. Enshi Geocentric Valley Scenic Canyon is a small and medium-sized karst canyon.

The basin of Enshi Geocentric Valley Scenic Area belongs to the subtropical monsoon warm and humid climate zone. The canyon is not obvious in summer and is connected in spring and autumn. It is not only mild, cool and pleasant, but also moist and fresh air with high negative ion concentration. The average temperature in January is 3-4 ℃, the average temperature in July is 25.0 ℃, the annual average temperature is 15.0 ℃, the precipitation is abundant, the average precipitation is about 1400mm, and the frost-free period is 260 days.

The mountains, water, clouds, fog, rain, snow, flowers and plants, trees, insects and birds in the basin are all beautiful, magical, vigorous and full of poetic and pictorial, rich in natural simplicity and beauty, roaming in the canyon, giving people the feeling of being immortal. Since records were made in 1959, there has never been a destructive earthquake of magnitude 4.7 or more in the Enshi Gexin Valley Scenic Area for more than 60 years, and it still maintains a good original ecological environment.

The rock types of the canyon of the Geocentric Valley Scenic Area in Enshi are limestone, dolomite and karst breccia of the Mesozoic Triassic Daye Formation and Jialingjiang Formation, which were formed about 0.2 billion years ago. The rock is highly soluble, karst is developed, and fissure water and dissolved interstitial water are abundant.

The scenic area is rich in plant species, rare and unique species, tall five-needle pine, larch, camphor, crape myrtle and other woody plants are whirling, graceful, vigorous and straight, covering the sky, medicinal plants, shrubs and other low vegetation is very dense, it is one of the most well-preserved areas in our province and even in China, and it is a good gene bank for genetic and breeding research. A variety of natural landscape environment, for a variety of types of animal and plant to create a complex living environment, the entire canyon landscape original unique, unique style.

According to the field survey, combined with the analysis of regional geological data, the basin of Enshi Gexin Valley Scenic Area is basically not affected by human engineering activities, no landslide, collapse, collapse and other adverse geological bodies are found in the whole river section, the riverbank rock wall is in a stable state, the adverse geological phenomena are not developed, the risk of geological disasters is small, and the safety of tourism facilities and tourists is guaranteed.

There are no sharp bends and large bends in the river course of the Geocentric Valley Scenic Area in Enshi. The height difference of the riverbed is uniform. There are few giant gravels in the river course, and few small and medium-sized smooth gravels and scattered distribution. No pebbles are concentrated and accumulated. The bedrock of the trough valley is exposed. The flowing water directly scours and the downward invasion is dominant, with little lateral erosion. The shape of the trough valley includes gentle beads of water, surges around gravel or through the bottom of gravel and dissolved pits, "lasagna" water flowing on thin muddy strip limestone, and bottomless green Tibetan Longtan. Several places of water flow in "splash" in "S"-shaped trough less than one meter wide, and continuous rumble of water.

The canyon enters the middle and lower section near the ancient stone bridge, and the banks are suddenly open, showing vertical landscape characteristics from top to bottom. The upper part is upright rock wall, the middle part is formed by slope accumulation, and the lower part is narrow river channel. The steep wall is dominated by limestone and karst breccia. Due to abundant precipitation and humid climate, Co2 dissolved in water reacts with carbonate in rock to form bicarbonate ion and calcium ion, the carbonate material is continuously reduced to dissolve the rock, and erosion, collapse, biological and other effects are added, and a large number of karst marks, karst gaps, karst ditches, karst grooves, small funnels, falling caves, stone peaks, karst waterfalls, travertine and other landscapes are formed on the rock walls and trough valleys. Under certain conditions, such as in a cave environment, the escape of Co2 can cause CaCo3 to precipitate again, which can not only form a variety of stalactites, stalagmite landscapes, various surface karst landscapes and underground cave landscapes, but also shape a colorful and mysterious underground world, with unique geological wonders being a typical representative.

The lithology of the stone hole formation is the thin layer limestone of the Triassic Jialingjiang Zu (T1j2). Due to the influence of the tectonic stress in the opposite direction, the thin layer limestone is crumpled and exploded from the bedding, forming a tectonic hole, which is named because of its shape like an eye.

The lithology of the stone mortar is a set of strata of the fourth (T1d4) of the Triassic Daye Formation. It is mainly composed of thick and medium thick layered limestone. Stone mortar is different in size and shape, mainly located at the bottom of the valley, the number can reach thousands, which is formed by the long-term water erosion of the river valley. Some stone mortars are like discs and big dustpans placed on the riverbed. Some are cylindrical, deep enough to store water, like a large water tank; Some bottoms have been penetrated, and waves can be seen floating past from below.

The lithology of Shishu is mainly thin-layered marl and dolemitic limestone of the Triassic Daye Group (T1d3). The 30 square kilometers of rocks in Shimen River are all layered limestone with obvious bedding. Because of being washed by running water, the bedding structure is more prominent, just like pages of books, hence the name.

This is the origin of mankind;

Here is the most mysterious cultural fertile soil in the southwest of Hubei, China;

Here 0.25 billion years ago the Triassic period gradually into the geological wonders of the mountain valley;

The "Jianshi Homo erectus Site" here 2.15 million years ago challenges the doctrine of human origin;

It is famous at home and abroad for the "ancient Ba Yan Road" of Chinese civilization 6000 years ago.