After checking in at so many "Shuizhai Miao" bubbles, even the "mud" is so beautiful!

Songyuan City, also known as "Bodune, New City", is located in the central and western part of Jilin Province. There are more than 70 (lake) bubbles in the area, including Chagan Lake (formerly known as Chagan Bubble), Kuli Bubble, Dabusu Lake (formerly known as Dabusu Bubble), Sanwang Bubble, Dezi Bubble, Jizi Bubble, Qingzi Bubble, Huaao Bubble, Yueliang Bubble, etc.

Checking in at so many "Shuizhaimiao" bubbles can not only make you feel the gracefulness of "reeds are lush and white dew turns to frost", but also let you appreciate the beauty of "the setting sun and the solitary wild goose fly together, and the autumn water and the sky are the same color" with the birds accompanying the sunset. The most well-known one should be Chagan Lake, which features large lake wetlands, grassland scenery, Mongolian customs, and Chagan Lake fishing and hunting culture.

But do you know that there is a Dabusu Lake in Qian'an County, Songyuan City, Jilin Province, which has many peaks, ravines, unique scenery and rich mineral deposits. It is also one of the largest saline-alkali lakes in my country. It was originally called Dabusu Lake. "Dabusu" means "salt-alkali" in Mongolian. It was changed from lake to lake in 1988.

Dabusu Lake is located in the center of the western depression zone of Songliao Plain. It is one of the larger lakes in the vast closed flow area between Nenjiang River and Xiliao River. Dabusu Lake is about 35 kilometers southwest of Qian'an County, Songyuan City, Jilin Province, with a total area of ​​about 56 square kilometers and a water storage capacity of about 603.27 million cubic meters. Moreover, the Dabusu Lake area is the lowest point in Songnen Plain, with the lowest point only 119.8 meters above sea level.

It was approved as a national geological park in 2009, and was also rated as a national land and resources science popularization base and a national "AAA" level tourist attraction.

Dabusu Lake in Qian'an County, Songyuan City (left, from GF-6 Earth Observation Image) and a bird's-eye view of Dabusu Lake (right, from the Internet)

On the east bank of Dabusu Lake, a series of geological processes such as subduction, erosion, wind erosion, and lake erosion have formed a magnificent mud forest landscape with various shapes and forms. Its landforms are in the shape of columns, towers, canyons, cliffs, and overlapping mountains, resembling the sawtooth of a wolf's tooth. Locals call it "Wolf Tooth Dam". Tens of thousands of mud pillars are like a forest, with peaks and ridges connected, steep soil walls and various shapes, giving a sense of a deep valley.

In spring, the grass sprouts in the mud forest, and the branches and leaves are like a canopy; in summer, the valley is full of green and the mountain flowers are in full bloom; in autumn, the ground is golden and gilded; in winter, the ground is completely bare, as magnificent as the wilderness. At sunset, the grassland of the mud forest seems to be stained with golden edges, dragging the setting sun and slowly disappearing on the horizon, like the last gentleness left by the light of the universe to the world. So, after checking in at so many "Shuizhai Miao" bubbles, the "mud" I encountered was so beautiful!

The mud forest with gullies and ravines in Qian'an County, Songyuan City (left, original image) and the mud forest that looks like the "roots of a giant tree" (right, original image)

Mud forest in spring, summer, autumn and winter (Photo from the Internet)

Mud forest at sunset (Photo from the Internet)

The mud forest covers a total area of ​​about 110 square kilometers. It is located on the second terrace on the east bank of the Dabusu Lake Basin. It is the only subaerial geological landform currently protected by the state. The mud forest landform can be divided into the formation zone, mature zone and extinction zone according to its development status. From the perspective of the stratigraphic lithology of the mud forest distribution area, the upper part of the mud forest is brown-yellow loess-like sub-sand soil (about 8.42 meters thick), with large pores and developed vertical joints; the lower part is gray-white fine silt (about 9.5 meters thick), mixed with yellow-green sub-sand soil (about 0.43 meters thick).

The Dabusu Formation where the mud forest is located contains a large number of densely packed ancient vertebrate fossils, including the first complete primitive cattle skeleton fossil discovered in my country (a national first-class cultural relic), as well as 655 paleontological fossils such as mammoths, woolly rhinoceroses, Hetao giant deer, primitive cattle, bison, wild horses, camels, hyenas, brown bears, freshwater snails, clams, etc. Based on the 14C determination results of the broken bones of woolly rhinoceroses, a late Pleistocene vertebrate, unearthed in the mud forest, scientists believe that the Dabusu mud forest was formed 20,540 years ago.

Vertebrate fossil fragments unearthed from the mud forest (left and middle pictures, pictures from the Internet) and saber-toothed tiger head fossil (right picture, picture from the Internet)

During the rainy season, the mud forest is constantly washed and eroded by rainwater. After a long series of geological actions, the current geological landforms with strange peaks and gullies are formed. The soil of the mud forest contains a large amount of soluble substances, a high content of saline-alkali substances, strong soil connectivity, and compactness in a dry environment. However, it has weak water resistance and will form a thick water film when it encounters water, making the soil particles very easy to disperse. Therefore, under the continuous leaching and dissolution of rainwater, mud forest landforms are easily formed. The special geological landforms provide materials for the study of geological actions such as subsidence, erosion, wind erosion, lake erosion, and possible geological disasters.

Jilin Provincial Seismological Bureau conducts survey on earthquakes, faults and related geological disasters in Qian'an area (original image)

Seeing the essence through the phenomenon: The mud forest, which has been formed after tens of thousands of years of wind and rain and the change of time, is a unique geological landscape and also a geological disaster phenomenon. Large-scale erosion and subsidence landforms pose a threat to the ecological geological environment of the mud forest reserve. In the mud forest reserve, there are gully landform units with thousands of gullies. Gullies constantly cut the flat terraces, causing large-scale soil and water loss. With the development of subsidence landforms, water channels gradually form in the soil. When the channels develop to a certain scale, it will cause the surface soil to collapse, slowly forming grooves, and finally developing into gullies. Subsidence landforms and gullies influence each other, and together constitute a landform with gullies crisscrossing.

The formation and evolution of mud forests are controlled by many factors: the banks of Dabusu Lake are high in the east and low in the west, and water will generate hydrodynamics when it flows into Dabusu Lake; the loess-like soil in the mud forest is mainly composed of weakly hydrophilic silt particles with large porosity, and the clay minerals are mainly illite and montmorillonite mixed layers with strong dispersion; climate, topography and other factors also promote the formation and evolution of mud forests. The large hydraulic gradient is the most important external factor in the formation of mud forests, while the special composition and properties of the soil in the mud forest itself are the internal factors of its formation.

Supplementary Science

Soil erosion refers to the process of soil destruction, separation, transportation and deposition under the influence of external forces such as wind, water, freeze-thaw, etc., while erosion is different from soil erosion. Erosion includes physical erosion and chemical erosion. The former is also called mechanical erosion, which is mainly a erosion phenomenon of particle loss under physical action.

The latter includes chemical weathering and chemical dissolution, which is a series of chemical-dominated erosion phenomena. Erosion landforms are landforms formed when surface water seeps into the ground through cracks on the surface, merges with groundwater to form runoff, and causes surface collapse.

This issue of science popularization ends! Friends, see you next time!

References in this issue:

[1] Sun Liying, Xu Zhitao*, Yan Hengqi, et al. Application of satellite thermal infrared remote sensing technology in earthquake monitoring and prediction in Songyuan earthquake area[R]. Jilin Provincial Seismological Bureau, 2025.

[2] Rui Xiangjian. Study on the destruction process and erosion mechanism of Qian'an mud forest[D]. Changchun: Jilin University. 2019.

[3] Zhang Manli, Sun Lingling, Yu Haibo, et al. Prevention and control measures for the Xuezijing collapse geological disaster in Qian'an Mud Forest National Geopark, Jilin Province [J]. Neijiang Science and Technology, 2014, 35(12), 63-63.

[4] Xu Zhitao, Li Mengmeng, Sun Jinggui, et al. Genesis and diagenetic geodynamic background of Middle Jurassic rhyolite in Deerbul area, Daxinganling[J]. Journal of Jilin University: Earth Science Edition, 2023, 53(3), 866-886.

[5] Ye Xiqing, Xu Zhitao*, Sun Liying, et al. Origin and tectonic significance of Miocene basalt in the Laohushan volcanic area, Jilin Province[J]. Geochemistry, 2024, 49(4), 1352-1366.

[6] Tang Zhuowei, Liu Saihong, Lin Zerong, et al. Late Pleistocene fauna of Dabusu, Qian'an, Jilin Province[J]. Acta Vertebrate Paleontologica Sinica, 2003, 41(2), 137-146.

[7] Wu Weiwei, Yang Jiansi, Su Jinrong, et al. Moment tensor inversion of the 2013 moderate-strong earthquake in the Qianguo-Qian'an earthquake source area of ​​Jilin Province and study of the regional seismogenic environment[J]. Chinese Journal of Geophysics, 2014, 57(8), 14.

[8] Liu Wenyu, Cheng Zhengpu, Nian Xiuqing, et al. Cause of Songyuan earthquake based on three-dimensional residual density structure[J]. Seismology and Geology, 2024, 46(2), 462-476.

[9] Yu Xiaohui, Shen Jun, Dai Xunye, et al. Growth stratigraphy reveals the tectonic characteristics of the Gudian fault in Songyuan area since the Quaternary [J]. Seismology and Geology, 2018, 40(6), 14.

[10] Chen Bo, Li Zhongwei, Xu Zhitao, et al. Earthquake safety assessment of the Qian'an County 200MWp photovoltaic power generation project (Phase II 150MWp), Qian'an County 144.1MWp photovoltaic power generation project, and Qian'an Jidian 50MW wind power project project sites[R]. Jilin Provincial Seismological Bureau, 2022.

[11] Chen Bo, Li Zhongwei, Feng Jingqiao, et al. Earthquake safety assessment of the fifth phase 100MW wind power project site in Sanjingzi Wind Farm, Fuyu City[R]. Jilin Provincial Seismological Bureau, 2021.

This issue's authors: Sun Liying and Ye Xiqing

Planning: Xu Zhitao Paul J Dario D D

Editor: Ye Xiqing Xu Dan

Review: Pan Xiaodong, Kang Jianhong, Cao Li, Chen Bo, Li Zhongwei, Chen Junjie, Lu Yanhong, Zheng Guodong, Wen Hongtao, Pang Jingyuan, Xu Jingsi, Zhao Chunhua, Zhao Guohui

Publicity: Feng Jingqiao, Yan Donghan, Chen Zhaoxin, Gu Guohui, Li Mengmeng, Zhang Xiaoqiu, Ren Xiaoyan, Wang Jingwei, Jin Wenhu, Song Yujia, Guan Sheng, Ma Xiaoxi, Liu Bing, Yang Liusongjun, Chen Linrong, Zhu Daqing

Produced by: Institute of Volcanology, China Earthquake Administration, Jilin Province Earthquake Administration, Naples Volcano Observatory, Italy, University of Strasbourg, France, Jilin University, Songyuan Earthquake Monitoring Center, Jilin Province

Disclaimer: All pictures and texts in this article are for public benefit and do not have any commercial value.