Mud volcano

Baiyanggou mud volcano landscape in Xinjiang mud volcano, as the name suggests, is composed of mud volcano. Mud is really made up of clay, rock debris, salt powder and other mud; volcano is not a volcano in the usual sense. Generally speaking, the most basic feature of volcanoes is that they are formed by magma and have magma channels, while mud volcanoes are formed by mud and do not have magma channels. However, the mud volcano is not only shaped like a volcano and has an outlet, but also erupts and ignites. The mud volcano group is located in baiyanggou Town, Wusu, Xinjiang. Within a radius of 200 meters, there are 80 remaining mud craters, 40 of which are erupting. Mud volcano is a natural phenomenon created by the earth and a rare natural landscape in the world. Only a few countries such as China, the United States, Mexico and New Zealand have mud volcano. Therefore, the mud volcanoes in Xinjiang are valuable resources for tourism. The surrounding colorful mountains and gullies are like thick colored oil paintings, which are of great ornamental value. Karamay mud volcano is located on a mountain peak in the north of Dushanzi. There are two main vents, about 100 meters apart. The larger vent is about 60 cm in diameter, more than 1 meter above the ground. Inside the nozzle is viscous mud, which is gray green and slightly oily. It keeps turning mud bubbles outward, and the collected mud overflows along the southwest opening. The gushing mud flow forms a cone-shaped mound on the surface with a diameter of more than 10 meters at the bottom and a dry mud block on the surface. Dushanzi, where the mud volcano is located, is also very distinctive. The mountain is about 7 kilometers long from north to south, 6 kilometers wide from east to west, and the highest peak is 1283 meters. It is isolated and protruding on the inclined plain, and faces hailifei mountain in Wusu County across the Kuitun River in the West. Mud volcano, also known as pseudovolcano, is a mud mound formed by underground natural gas with water, mud, sand and rock cuttings continuously ejecting from the surface under pressure. It can be the end of volcanic activity or the product of natural gas. Dushanzi mud volcano belongs to the latter. There are many mud volcanoes between Tainan and Kaohsiung in Taiwan Province. Dushanzi mud volcano has high scientific value and high ornamental value. It is close to Dushanzi urban area and has convenient transportation. It is relatively combined with the first well, the first pot and other scenic spots. It is also a scenic spot overlooking Dushanzi urban area. Domestic and foreign tourists to Dushanzi often come to watch it.

Mud volcano

Mud volcano: mud and gas ejected from the ground at the same time and accumulated. Most of them are cone-shaped mounds or basin cave shaped, and the tip of the mound often has a depression, from which mud and gas are ejected.

brief introduction

Mud volcano, as the name suggests, is a volcano made of mud. Mud is really composed of clay, rock debris, salt powder and other mud; volcano is not a volcano in the usual sense. The most basic feature of volcano is that it is formed by magma and has a magma channel, while mud volcano is formed by mud and does not have a magma channel.

However, the mud volcano is not only shaped like a volcano and has an outlet, but also erupts and ignites.

Domestic reports

In 2002, the Wusu mud volcano in Xinjiang, reported by some domestic media, was distributed in the valley at the north foot of Tianshan Mountain in the southwest of Wusu, near the baiyanggou coal mine. The active erupting mud volcanoes present as a mud spring and a mud pool. They are mostly round and small in size, ranging in diameter from a few centimeters to 1-2 meters. They are scattered in the hillsides and valleys of about half a square kilometer.

The mud surface in the spring pool is bubbling from time to time, as if the earth is boiling.

Mud emits odorous gases such as biogas and hydrogen sulfide, some of which can be ignited. However, people did not expect that the temperature of the rolling mud was so low that they felt cold when they put their hands in it. Therefore, some people called mud volcano "cool volcano".

Sometimes, the eruption of mud volcano is distributed in beaded shape along the faults or fissures on the surface of the earth, some of which are deep gullies, some of which are like deep wells. The churning mud continuously overflows from the spout and dries up into mud mounds. The shape of mud mounds is similar to that of ordinary volcanic cones, but the scale is much smaller than that of volcanic cones. Generally, the diameter of the base of mud volcanic cones is only a few meters to tens of meters, and the height is generally not more than 10 meters.

Those dry mud volcanoes often form various forms of landscape. In baiyanggou, in addition to the mud volcanoes that are erupting, there are many mud volcanoes that have stopped erupting. They are five shaped, ridge shaped, funnel-shaped Thousands of gullies and mountains, red, yellow, orange, ochre, green, colorful, indicating that there had been a large-scale mud volcano activity before.

In 2002, wusuni volcano erupted. The active erupting mud volcanoes present as a mud spring and a mud pool. They are mostly round and small in size, ranging in diameter from a few centimeters to 1-2 meters. They are scattered in the hillsides and valleys of about half a square kilometer. The mud surface in the spring pool is bubbling from time to time, as if the earth is boiling.

In China, in addition to Xinjiang, only active mud volcanoes have been found in Kaohsiung and Hengchun areas of Taiwan, where mud volcanoes not only have typical landforms, but also have natural landscapes of eruptions.

Foreign volcanoes

Mud volcanoes are rare in other parts of the world. The most famous mud volcanoes are Makran in Iran and Buza in Romania. The largest mud volcanoes are distributed in Baku in Azerbaijan. Yellowstone Park in the United States is famous for mud volcanoes.

At present, there are still many problems about the origin of mud volcanoes, and there are debates in the academic circles, but they can be divided into two types.

On April 14, 2007, a large number of houses were flooded by mud from a "mud volcano" in the siduazo area of East Java, Indonesia.

In the distance, the place where the oil drilling accident happened was covered with white smoke. Since the eruption of a "mud volcano" caused by a local oil drilling accident in May 2006, the mud has flooded the roads, railways and factories around it, and displaced 15000 people.

After the ms7.7 earthquake occurred in southwest Pakistan on September 24, 2013, an island emerged near Gwadar Port, about 400 km from the epicenter, causing local residents to watch. Earthquake experts generally speculate that the island is likely to be caused by the submarine mud volcano eruption, and it should disappear under the impact of waves in a period of time.

Formation mechanism

The formation mechanism of mud volcanoes mainly includes earthquake eruption, deep sediment stratification and gas content, fault activity, and artificial drilling. As early as the middle of the 19th century, it was recognized that the volcanic activities were related to tectonic activities: they mostly occurred at the intersection of large faults.

Therefore, we can verify the control of the fault to the mud volcano by drilling and observing its relationship with the earthquake, and judge the fault and its strike according to its development.

Generally speaking, the eruption frequency of mud volcanoes has a certain internal relationship with earthquakes: soon after an earthquake, mud volcanoes often erupt, such as kandewari mud volcano eruption in southern Pakistan after a 7.0 earthquake that affected northwest India and southern Pakistan on January 26, 2001.

Some people think that the formation of mud volcano is mainly related to the following factors: 1) sedimentary basin with high deposition rate; 2) clay minerals with more ILLITIZATION; 3) expansion of pore fluid; 4) deep hydrocarbon rich fluid; 5) upper overburden with no water or low permeability; 6) lateral or vertical compression of salt deposits; 7) seismic activity.

Genetic classification of terrestrial and submarine mud volcanoes

1) The geological origin is mainly composed of thick sedimentary caprock (8-22km) composed of terrigenous sediments.

It contains plastic shale. The density of the rock is high, and there is gas accumulation in the deep.

The formation pressure is abnormally high; 2) tectonic origin: high deposition rate of sediments or overthrust layer leads to rapid subsidence of sedimentary cover, mud bottom splitting or anticline folding, fault development and lateral structural compression, seismic activity and crustal equilibrium; 3) geochemical origin: hydrocarbon generation and dehydration reaction of Gutu minerals in the exploration area; 4) hydrogeological solidification: fluid flowing along faults Flow.

Most scholars believe that there are two key factors for the formation of Mud Volcanoes: faster deposition rate and lateral compression of active continental margin.

The study shows that there are two basic processes in the formation of submarine mud volcanoes: first, mud volcanoes develop directly on the seafloor, or mud splits to the seafloor after the fluid penetrates the mud splitters. If the fluid does not migrate to the seafloor, mud volcanoes will not form, but mud diapirs will form.

Secondly, the fluid migrated upward along faults or fractures or leaked to the seabed to form mud volcanoes.

Post eruption landforms

A mound of mud raised through overlying sediments. The mud crater is usually very shallow and may spray mud intermittently. Mud volcanoes are vulnerable to erosion, and ejecta continue to rebuild their cones.

The formation of some mud volcanoes is related to hot springs, where a large amount of gas and a small amount of water react with surrounding rocks to form boiling mud. It has two varieties: porridge pot and pigment pot. The former is a boiling mud basin that erodes the surrounding rocks, and the latter is a boiling mud basin that is dyed yellow, green or blue by the minerals of surrounding rocks.

Other mud volcanoes, which are not of magmatic origin, only occur in the oil field areas with relatively new age and unconsolidated soft rock strata.

Under the action of compressive stress, methane and other hydrocarbons change

Chinese PinYin : Ni Huo Shan