1. Busy fishing for coal on the banks of the Yellow River. Residents living on the banks of the Yellow River in western Shanxi often have the experience of fishing for coal. Whenever after a heavy rain, the Yellow River swells, and in the rolling turbid current, lumps of coal often drift down with the waves from the upper reaches. As the floodwaters did not recede after the rain, many residents along the river chose favorable locations to fish floating coal from the floodwaters with wooden poles. If the location is well chosen and there is a lot of coal in the river, enough coal can be obtained for a year in one operation. In Hejin, at the exit of the Yellow River Gorge thousands of miles away from Shanxi and Shaanxi, the river channel widened as it entered the Fenhe Plain and the flow rate slowed down, so coal accumulated there in large quantities. At this time, men, women and children flocked to the river beach to pick coal, which was a boom. Strong laborers gather, pull and move coal, while women and children pick up scattered small pieces of coal and guard their own coal piles. At this time, the river beach was crowded with people, shouting, shouting, and scrambling, like a lively market.
The floating coal in the Yellow River is mainly washed down by flash floods from the coal-producing areas of Shaanxi and Inner Mongolia. They are lignite with low density, and there are also other coals. Because there is a lot of sediment in the Yellow River water and the density of the river water is high, light bituminous coal will also float on the water. Nowadays, with the soaring price of coal, almost all the coal exposed on the surface has been dug up, so the lively scene of fishing for coal from river beaches has gradually disappeared since the 1980s.
2. Shanxi's special "coal"
One match can light a furnace of coal. It sounds like a strange story, but the fact is that it happened in the Hequ-Baode area, where coal seams The content of combustible volatiles is particularly high. Just strike a match and light the stove without the need for paper or firewood or straw. Today this high-quality gas coal is extremely difficult to find.
The coal can be simmered for a week without being extinguished. Generally, people can seal the stove and burn it for one night, and then open it the next day to boil a kettle of water. If the fire is properly sealed, it can burn for a day and a night without being extinguished. As for the coal in the Huyan Mountain area south of Gujiao in Taiyuan, it is not unusual to keep the fire sealed for 2 to 3 days. With good technology, it can be sealed for a week without extinguishing it. The locals call it "charcoal back to one's parents' house". It turns out that the Carboniferous fat coal here was metamorphosed into high-grade anthracite coal by the high temperature of the magma rock intruding underground. Most of the flammable components in the coal escaped and disappeared, leaving only the flame-resistant part, but it was particularly burned. Therefore, the stove after sealing the fire can burn slowly for 6 to 7 days without going out.
3. Chai Pi Charcoal under volcanic rocks
In Fanzhi Beishan, there are hundreds of square kilometers of basalt, where "Chai Pi Charcoal" is produced. It is the youngest coal, lignite, formed from trees buried by volcanic eruptions more than 20 million years ago under conditions of semi-isolation of air. Because it retains the shape of the original tree well, it can be used as firewood after being dug out, and burns better than firewood, so people call it "firewood splitting charcoal".
Chaipitan
4. Coalfields under the Neoarchaean
Neoarchean gneiss refers to the metamorphic rock formations in the early crust of the earth 2.5 billion years ago. It was supposed to be at the bottom of a layer thousands of meters thick beneath the coal seam. With a time interval of more than 2 billion years and a space interval of several kilometers thick, no one would look for coal under the gneiss. However, near Yinchang Township, Nanshan, Lingqiu County, coal mines were found under the gneiss, becoming the only coal supply base in Lingqiu County. This geological miracle is a little joke made by the later crustal movement. It turns out that the Yanshan movement that occurred 150 million years ago turned over the Neoarchean gneiss deep in the earth's crust and pushed it onto the Carboniferous coal-bearing strata. This led to the strange discovery of coal seams under the gneiss. Example.
5. Ningwu’s Thousand-Year Fire Cave
20 kilometers south of Ningwu City and north of Dongzhai Town, there is a special scenic spot "Luanqiao Smoke Rainbow". That refers to the smoke rising from the rocks on the west slope of Luanqiao Village, just like the white water vapor coming out of the cooling tower of today's power plants and filling the mountains. Under the slanting sunlight, the underground fire evaporates the underground water vapor, and a rainbow of seven colors will appear. Luanqiao Yanhong got its name from this. This landscape has been around for hundreds of years, and it still emits "white smoke" day and night. It turned out to be spontaneous combustion of coal seams. Along the northeast direction of Guanchuan Mountain, within a span of more than ten kilometers, there are dozens of coal seams burning spontaneously. It even happened right next to the Wannian Ice Cave, 200 meters away from the ice cave on the top of the northern mountain. In order to match it with the ice cave, people named it "Thousand-Year Fire Cave", so the eternal ice cave and the thousand-year-old fire cave met unexpectedly, forming a natural wonder of sharp contrast between fire and ice.
There are Carboniferous coal seams distributed on Guanchuan Mountain. Because the coal there has a high sulfur content and the coal is a gas coal with high volatile content, under direct sunlight, the decay of nearby fallen leaves will produce The heat ignited the coal seam, causing spontaneous combustion of the coal seam. Once a coal seam catches fire, wind and rain cannot extinguish it. Even if the surface layer is extinguished, the coal seam deep in the rock layer can still burn. It will not be extinguished until coal ash accumulates and blocks the rock cracks, preventing outside air from entering. But then the newly eroded coal seams will spontaneously ignite again. Therefore, the Millennium Fire Cave does not refer to a specific spontaneous ignition point, but a collection of spontaneous ignition points one after another.
After the coal seam is burned, only non-combustible stony coal ash is left, which greatly reduces the volume of the coal seam. As a result, the upper rock layers collapsed into pits due to the loss of support from the coal seams below. Therefore, collapsed fire pits are scattered all over the local mountains, ranging from 1 to 30 meters in diameter. There are burning red mud and rocks, and there are half-burnt fire pits beside the holes. trunk.
The newly extinguished fire cave
Spontaneous combustion in the Datong coalfield in Shanxi Province is also very serious. It burns deep underground and makes a roaring sound, which was mentioned in the "Shui Jing" by Li Daoyuan of the Northern Wei Dynasty. "Note" contained in it was later used by Soviet experts in the 1950s as evidence that modern volcanic activity was still ongoing. For this reason, in the 1970s, citizens panicked that "Datong is located in an active volcanic zone." Later, the Datong Mining Bureau sent experts to demonstrate that it was a misunderstanding caused by spontaneous combustion of underground coal seams.