Huanglian tulin

--Huanglian earth forest is the earth forest of huanglianguan Town, which is a geomorphic landscape developed on a set of ice water freeze-thaw debris flow accumulation. The earth forest is magnificent and has different shapes.

--This is a lack of protection of the natural heritage, the scenic area has been able to see the dumping of soil columns, but this natural "Museum" shows the world the uncanny workmanship of nature.

--The soil forest is weathered and damaged very quickly, so those who want to see it should go there as soon as possible, and they may not be able to see it later.

Huanglian tulin

Huanglian earth forest is the earth forest of huanglianguan Town, which is a geomorphic landscape developed on a set of ice water freeze-thaw debris flow accumulation. Huanglian tulin is located in huanglianguan Town, 30 km south of Xichang City, Liangshan Yi Autonomous Prefecture, Sichuan Province, more than 30 km away from the urban area of Xichang City, Sichuan Province, in the valley slope area on the left bank of Anning River.

Introduction to soil forest

With an area of about 1.3 km2 and an altitude of about 1500 m, the earth forest is magnificent and has different shapes. Some are like ancient castles, some are like boundless forests, some are like a sword leaning on the sky, some are like a galloping horse roaring in the sky, some are as naive as pandas, some are like monkeys climbing and playing, and some are like lions and tigers fighting. The whole earth forest scenic area has beautiful scenery.

Huanglianguan town gets its name because there are many Coptis trees on the hillside.

Soil forest is a kind of special geomorphic landscape formed under specific material conditions, landform conditions, internal and external dynamic geological conditions, climate and environmental conditions. It has a certain scale of Huanglian soil forest with unique ornamental value and certain scientific value.

The texture of soil forest is yellow gravel. Geological experts say that the formation of earth forest can be traced back to the ice age of 80 million to 100 million years. During the period of ice water deposition, debris was brought by ice water flow, and sand gravel layer was formed. After diagenesis and hardening of sand gravel layer, cracks or fissures (called cracks in Geology) appear under the influence of new crustal movement. The surface water (mainly rain water) seeps and penetrates downward along the cracks. Over time, the cracks gradually expanded and deepened due to erosion, and finally split into mounds and columns, becoming today's soil forest. The Sandy Rock at the top of the tulin is a kind of colloidal calcium structure, which is not easy to be weathered and washed, so it is mostly mushroom shaped.

The wonders of the earth forest vary from person to person, from time to time, and from feeling to feeling. In children's eyes, this is the zoo. The running horse roars up to the sky, and the panda is charmingly naive. The monkeys climb and play, and the lions and tigers fight against each other. They realize that everything is in shape. The best thing about Shilin is dusk. When the scenery is hazy and the sound stops, people will hear all kinds of strange sounds in the fantasy. Everything solidifies here, and you need to let go of your imagination.

natural environment

Huanglianguan town is located near Xichang, which belongs to the subtropical plateau monsoon climate with an average annual temperature of 17 ℃, an average temperature of 22.6 ℃ in July and an average temperature of 9.3 ℃ in January. The frost free period is 273 days, the average annual sunshine hours is 2431 hours, the average annual precipitation is 1013 mm, the dry and wet seasons are distinct, and the rainy and hot seasons are the same. The study area is located in the central axis of Sichuan Yunnan uplift belt, east of ANNINGHE FAULT and northwest of Zemuhe fault. It is mainly composed of a series of North-South trending folds, compressional faults and low order compressional torsional or tensional torsional faults. Since Cenozoic, the tectonic activity in this area is still relatively strong. Along the Anning River, Zemuhe and Luoxi large faults, the Anning River Valley, Xichang and Butuo subsidence basins have been formed respectively, resulting in local small folds and faults in the tertiary and Quaternary strata. Up to now, there are still many inherited fault activities, and many hot springs are exposed along the faults. The seismic activity is strong and frequent. The strata exposed in the study area are mainly frozen thawed debris flow accumulation (q4slf), which are distributed in the Piedmont slope to piedmont gentle slope accumulation platform of huanglianguan town. The surrounding bedrock is quartz sandstone of Baiguowan formation (t3bg). Huanglian tulin is located on the left bank of Anning River Valley. The surface water is mainly supplied by atmospheric precipitation. Because the terrain gradient of soil forest distribution area is relatively low, it has a certain catchment advantage, so the surface water in the area is rich during rainfall. The surface water is mainly discharged into Anning River through the runoff of Piedmont valley. Groundwater is mainly composed of loose accumulation pore water and bedrock fissure water, and the main source is still atmospheric precipitation flowing into Anning River valley through underground runoff.

Cause of formation

Material composition

The soil forest development area is located in the Piedmont accumulation fan of Anning River Valley. According to the existing data, there are different opinions on the genesis of the deposits. According to the geological survey of Luoji Mountain Glacier, the deposits are mainly composed of debris flow deposits on the left bank of Anning River Valley, and the deposits are mainly composed of yellowish brown silt silty clay, intercalated with gravel soil layer. The particle size of the gravel is 2 ~ 10 cm, showing angular or sub angular sandstone fragments. The occurrence of gravel soil layer shows the occurrence state of debris flow accumulation fan, which is fan-shaped along the gully to the gully mouth (Fig. 3), with an inclination of about 6 degrees. According to the material composition of the accumulation body, it is inferred that it is ice water freeze-thaw debris flow. The accumulation body is semi cemented, and the cementation type is iron argillaceous cementation. There is a thin gravel layer or gravel layer in the middle, with a thickness of about 5 cm. It is lenticular, slightly inclined downstream, and the dip angle is less than 8 °. There is a gray black cover (weathering crust) on the top of the accumulation body, which is mainly composed of silicon, aluminum and iron. These materials are relatively stable, not easy to be leached, and have high strength and strong weathering resistance after formation. Because the accumulation body is semi cemented, it is easy to be washed by rain. At the same time, due to the protective effect of the top cover, and the gravel or gravel layer in the middle of the soil column, it plays a similar role as "stirrup", which ensures the stability of the soil column. These provide an important material basis for the formation of soil forest.

Geomorphic conditions

On both sides of the Anning River Valley, we often see such debris flow deposits in front of the mountain, but not all of them can develop into earth forests, or the earth forests can reach the scale of the earth forests in huanglianguan town. This is because the formation of soil forest is also related to its landform: because the accumulation body is located in the transition zone from slope to gentle platform, gullies are often developed in such a section, and the gullies are deeply cut, which provides conditions for the leaching of surface water. Through the field investigation, it is found that the development of soil columns can also be seen in the shallow cutting area of the gully, but these soil columns are small in scale and single in shape. Therefore, it is not difficult to find that the formation and development of soil forest has an important relationship with its geomorphic position and morphology.

Neotectonic movement conditions

The formation of Huanglian tulin was completed in the process of regional neotectonic movement. In the stage of tectonic subsidence, Anning River valley basin was formed, and debris flow and alluvial proluvial deposits were formed after ice water freezing and thawing, which formed the material basis for the development of landforms. Then, the debris flow deposits were uplifted and cut into various forms of cracks, forming the landforms of soil and forest development. Of course, on the other hand, the deposition process of debris flow deposits was due to physical factors In the process of soil shrinkage, mud cracks and other cracks will be formed. When the neotectonic movement turned into a stable period, the current eroded and leached the accumulation body, which provided favorable conditions for the formation of soil forest.

External dynamic condition

During the development of soil forest in Huanglian, there are various external dynamic actions, such as flowing water, gravity and physical weathering, among which flowing water is the most important. On the one hand, the surface water erodes and cuts down to form various forms of gullies. These gullies crisscross and form the landform of soil column, earth wall and soil screen on the original accumulation body. On the other hand, the leaching of surface water and other physical weathering processes form a variety of landscapes in the soil forest.

climatic conditions

After the formation of soil forest, due to its material properties, its stability is poor, far from being compared with stone forest. The formation of soil forest is also related to its environment and climate. It needs dry climate, annual rainfall should not be too large, rainfall frequency is low, on the whole, the dry season is longer than the rainy season. Huanglianguan area in Xichang belongs to the monsoon climate of subtropical plateau. The annual average sunshine hours are 2 431 h. The dry and wet seasons are distinct. The rainy and hot seasons are the same. The dry season is long and the air is dry, which provides a good climate condition for the formation of soil forest. Under such climate conditions, the soil forest column is larger, not easy to be destroyed, and more spectacular in momentum.

Address: huanglianguan Town, Xichang City, Sichuan Province

Longitude: 102.20283296235

Latitude: 27.676593632722

Tour time: 2-3 hours

Traffic information: Huanglian tulin is located in huanglianguan Town, 30km south of Xichang City, about 30km away from the urban area of Xichang City.

Bus: take the bus from Nanqiao station in Xichang City to Huanglian, Huangshui, AQI and Dechang. There are many times, about 5 minutes, 5-7 yuan, about 30 minutes.

Ticket information: 20 yuan per person

Opening hours: all day