Where do these "ice, ice", "circles" and "rocks" that grow on the ground come from?

Permafrost is a special soil that freezes below zero degrees Celsius and is found in high latitude and high altitude areas around the world, such as the Daxingan Mountains and the Qinghai-Tibet Plateau in China.

Permafrost has extremely special properties, so it can form a variety of strange permafrost landscapes. The "black magic" mentioned in the article is caused by permafrost.

Groundwater is coming out.

An important condition for the formation of permafrost is the presence of water in the soil. When the water keeps freezing and melting, many interesting landforms are formed.

Subsurface ice, as the name implies, is ice that forms in permafrost and includes dissociated ice, buried ice, and vein ice. Subsurface ice is an extremely important water resource in permafrost areas, and its presence has a significant impact on permafrost engineering and climate change.

Subsurface ice. Image: Wikipedia

Frozen mounds are landforms where the soil rises upward due to the increase of ice under freezing conditions. Specifically, the thaw layer freezes from top to bottom and bottom to top in winter, the cross-section of water passing through it decreases, the water on the frozen layer is under pressure, and water migration occurs during the freezing process, which can lead to ice accumulation. As the frozen surface progresses downward, when the water pressure on the frozen layer is greater than the strength of the overlying soil layer, the ground surface will be lifted and a frozen mound will be formed.

Frozen mounds are a common type of permafrost landform in permafrost areas of China. The diameter of the bottom of the mound varies from a few meters to tens of meters, and the height is 1-2 meters, some can reach 3-5 meters. The surface of the mound is often crisscrossed with cracks. The largest known frost mound in China is located at level 62 of Qinghai-Tibet Highway. It has a diameter of 40-50 meters at the bottom and is 20 meters high.

Section of a frozen mound. Image: Wikipedia

In permafrost areas, sometimes silvery ice can be seen from far away, which is the ice cone. When the melting layer freezes back in winter, the groundwater pressure increases and breaks through the overlying soil layer and overflows to the surface, where the ice body gradually increases and rises in a cone shape. Water overflows ice, along the original groundwater, flow path extension, and the formation of ice cones.

The shape and size of the ice cone vary greatly, some are 2~3 meters in diameter, others are ice slopes extending tens of meters or even hundreds of meters, and sometimes there are several overflow outlets. The apexes are widely distributed in the tundra region.

Melting ice cone. Photo: China Science Fair

Permafrost also likes iron rings.

Have you ever seen a ring of gravel? Permafrost has a unique freeze-thaw separation effect that separates different materials, so this "envelope" phenomenon tends to occur in permafrost areas. Stone rings and frozen grass rings are typical of "envelope" landforms.

On a gentle, thick surface, after freeze-thaw sorting, the soil and small fragments are concentrated in the middle, and the rocks are pushed out to the periphery in a polygonal or nearly circular shape as if someone has consciously made a circle of rocks. This frozen landform is called a stone ring.

In the area where the stone ring is formed, there must be a mixture of stones and thickness of soil, and sufficient water is also needed. The temperature fluctuates at zero degrees Celsius for a longer period. Only then will the stones mixed in the soil be squeezed out.

Stone rings are often found on flat ground not far from river floodplains or at the mouths of rivers, where the conditions for their formation are present.

Turf rings form polygonal or nearly circular turf on the ground that is exposed and covered with debris. This is a rare ice-edge feature in the tundra, with a reddish-yellow center and green periphery. The mechanism and process of its formation are not yet well understood by scientists.

Frost swell ring image source: Reference [1]

Due to fractures, when water freezes and expands, the rock breaks into many small pieces, or due to temperature changes, the minerals that make up the rock expand and contract unevenly, causing the rock to crack. In such cases, a large number of angular rocks and rock chips of different sizes are produced. In conditions of gentle topography, most of the rock debris will remain in place, forming gravels that cover the ground and are called rocky seas.

The rocks are found on the Qinghai-Tibet Plateau, the western mountains, and the northern tundra of the Daxinganling. The development of the Stone Sea requires not only hard and friable rocks but also certain hydrothermal conditions. That is, the rocks should have a certain amount of water, the temperature of the water should vary greatly, and the temperature should fluctuate continuously at 0℃ for a long time.

The material source and generation of rock flow slope and rock sea are similar, but the geomorphology of both is different. Stones are mostly found in gentle hills, while rocky slopes occur on mountain slopes.

The rock masses and rock debris of Shiluipo are not only produced by in situ freezing and weathering on the slope but also rolled down from the mountain by gravity. This determines the composition of the Liu Shi slope be fine at the top and coarse at the bottom, with small rock debris on the slope and large rocks at the bottom.

The pomegranate slope is a common ice-edge landform in permafrost areas. It is widely distributed in the Daxinganling and high mountain and plateau permafrost areas in western China, and can be found almost everywhere.

Under natural conditions, the surface material often varies in thickness. Due to the different thermal conductivity of stone and soil, the freezing rate is also different. When the thermal conductivity of gravel is high, it will freeze first and water will migrate to form ice near the stone. When the water freezes, the volume expands, causing the gravel to move. In this way, the coarse and fine materials are separated. This phenomenon is called freeze-thaw sorting by scientists because it acts like a sieve, separating the different materials.

The stones are formed by repeated freeze-thaw and freeze-thaw sorting of the rubble on the slopes of the Lauchee so that the rubble collects in the lower part and extends down the slope under the force of gravity. Therefore, stone strips often exist at the same time as the rock-pile slope, and the gravel and fine-grained materials are arranged along the slope in a band.

Rocks and rock debris produced by cold and freezing weather gather in grooves at the bottom of the slope under the force of gravity, and the gravel slowly moves down the grooves, forming a small river filled with stones, hence the name Stone River.

Stone Sea, Sixteen Slopes, and Stone River are brothers of the same clan and are organically linked to each other. They often appear on the same mountain at the same time. They are often paved with boulders from the mountain, scattered on the slopes, and flowing at the foot of the mountain.

Natural "rubble" can only be formed when rocks are in a special permafrost environment. Although its form is peculiar, it can only bring a continuous shock to human beings if they take care of the fragile permafrost environment.