How is coal formed, as the title thanks

Coal is a solid combustible organic rock, which is mainly formed by biochemical action of plant remains, buried and then transformed by geological processes. Commonly known as coal. The formation of coal is transformed into peat or saprolite by peatization or saprolite by plant remains accumulated in stagnant water bodies at normal temperature and pressure on the surface; After peat or saprolite is buried, it sinks to the deep underground due to the decline of the basin basement, and is transformed into lignite by diagenesis. When the temperature and pressure gradually increase, it is transformed into bituminous coal to anthracite through metamorphism.

Peat is the process by which the remains of higher plants accumulate in swamps and are transformed into peat through biochemical changes. Sludge is the process by which the remains of lower organisms are transformed into sludge through biochemical changes in swamps. Saprolite is a silt-like substance rich in water and asphaltenes According to research, almost all plant remains, as long as they have the conditions to become coal, can be converted into coal.

However, the coal formed from the remains of lower plants has a small distribution range and thin thickness, and is rarely used. The coal that is widely distributed, large-scale, and widely used is formed by the remains of higher plants (mainly ancient ferns, pines and cypresses, and the remains of some angiosperms).

Coal is a kind of sedimentary rock with combustible properties that is accumulated in lakes, bays, shallow seas and other places by ancient plant remains, and transformed into complex biochemical and physicochemical processes. The chemical composition of coal is mainly carbon, hydrogen, oxygen, nitrogen, sulfur and other elements. Spores, pollen, etc., which are made up of plant cells, can be found in the coal under the microscope, and plant fossils can also be found in the coal seam, all of which can prove that the coal was formed by the accumulation of plant remains.

Scientists have found that there have been times of humid climate and lush vegetation on the earth, such as the Carboniferous, Permian (about 300 million years ago), and the Jurassic (about 100 million years ago). At that time, large numbers of thriving plants piled up in closed lakes, swamps or bays, etc., and were quickly covered with sediment, and after hundreds of millions of years, the plants turned into coal and the sediment into sandstone or shale. Due to rhythmic crustal movements and repeated accumulations, there tend to be many coal seams in the same area, each layer of coal separated by rocks.

Coal is a layer of extremely thick black humus accumulated on the ground by the branches, leaves and rhizomes of plants for millions of years, which is continuously buried in the ground due to changes in the earth's crust, isolated from the air for a long time, and formed by a series of complex physical and chemical changes and other factors under high temperature and high pressure.

Coal is formed by plants under high temperature and high pressure under the soil layer after a long geological process.

In ancient times, plants were buried deep in the ground, and after a long period of physical and chemical changes, they became coal.

Coal is made from mud in the ground.

Coal is a sedimentary organic mineral converted into plant remains through biochemical and physicochemical reactions, and is a mixture of a variety of polymer compounds and minerals.

Coal was buried slowly in the ground hundreds of millions of years ago.

Slow formation. Whether it is China or other countries around the world, coal is usually divided into genetic classification and industrial classification (or practical).

classification) two systems. The genetic classification is based on the different original plants that form coal.

1. Coal is the product of the earth's crustal movement, far away in the Paleozoic Era more than 300 million years ago, the Mesozoic Era more than 100 million years ago and the Cenozoic Era tens of millions of years ago, a large number of plant remains after complex biochemical, geochemical, physicochemical processes after the transformation into coal, from plant death, accumulation, burial to transformation into coal through a series of evolutionary processes, this process is called coal-forming action.

2. It is generally believed that the coal-forming process is divided into two stages: the peat stage and the coalification stage. The former is mainly a biochemical process, and the latter is a physicochemical process.

3. The peat stage is the continuous reproduction of plants in peat swamps, lakes or shallow seas, and their remains are constantly decomposed, combined and accumulated with the participation of microorganisms, and the leading role in this stage is biogeochemistry. The lower plants form saprolite through biogeochemical processes, and the higher plants form peat, so the first stage of coal formation can be called the saprolite stage or the peat stage.

4. The coalification stage consists of two continuous processes: under the action of geothermal heat and pressure, the peat layer undergoes various changes such as compaction, water loss, limb aging, and induration to become lignite. The density of lignite is greater than that of peat, and there is also a significant change in composition, with a relative increase in carbon content, a decrease in humic acid content, and a decrease in oxygen content.

Because coal is an organic rock, this process is also called diagenesis.

5. It is the process of transforming lignite into bituminous coal and anthracite. In this process, the properties of the coal change, so this process is also called metamorphism. As the earth's crust continues to sink, so does the overburden of lignite.

Under the action of geothermal and static pressure, lignite continues to undergo physical and chemical changes and is compacted and loses water. Its internal composition, structure and nature have undergone further changes. This process is the metamorphism of lignite into bituminous coal.

Bituminous coal has a higher carbon content than lignite, the oxygen content is reduced, and humic acid no longer exists in bituminous coal. Bituminous coal continues to undergo metamorphism. Change from low to high degree of metamorphism.

As a result, long-flame coal and gas coal with low metamorphic degree, fertile coal and coking coal with medium metamorphic degree, and lean coal and lean coal with high metamorphic degree have appeared. The carbon content between them also increases with the deepening of the degree of deterioration.

6. Temperature plays a decisive role in the chemical reaction in the process of coal formation. As the strata deepens and the ground temperature increases, the degree of coal metamorphism gradually deepens. The longer the high temperature acts, the higher the degree of metamorphism of the coal and vice versa.

Under the simultaneous action of temperature and time, the metamorphic process of coal is basically a chemical change process. The chemical reactions carried out during its change are diverse, including dehydration, decarboxylation, demethane, deoxygenation, and polycondensation.

7. Pressure is also an important factor in the process of coal formation. With the precipitation of gas and the increase of pressure in the coalification process, the reaction speed will become more and more many, but it can promote the change of the physical structure of coal in the coalification process, and can reduce the porosity, moisture and increase the density of coal with low metamorphic degree.

1. Coal is a layer of extremely thick black humus accumulated on the ground by the branches, leaves and rhizomes of plants for millions of years, which is continuously buried in the ground due to the changes of the earth's crust, isolated from the air for a long time, and under high temperature and high pressure, after a series of complex physical and chemical changes and other factors, the formation of black combustible sedimentary rock, which is the formation process of coal cherry blossom rolling.

2. The thickness of the coal seam in a coal mine is related to the rate of crustal decline and the amount of plant remains accumulated in the area. The speed of the earth's crust is fast, and the remains of the plant section Yu Songshu are piled up thickly, and the coal seam of this coal mine is thick, on the contrary, the speed of the earth's crust is slow, and the plant remains are piled up thinly, and the coal seam of this coal mine is thin.

Coal is the remains of plants for thousands of years in ancient times, the main thing is trees, piled up on the ground to form a very thick black humus, due to the continuous changes of the earth's crust, buried in the ground, after a long period of geological action, isolated from the air for a long time, and under high temperature and high pressure, and then through a series of physical and chemical changes and other factors, the formation of black combustible sedimentary rock, so that the formation of coal.

In the history of the earth, the most favorable geological ages for the formation of coal are mainly the Carboniferous and Permian of the Late Paleozoic; Jurassic of the Mesozoic Era; and the Tertiary of the Cenozoic.

When we look at the cross-section of coal under the microscope, we can clearly see the growth ring lines of trees, which is a strong proof that coal evolved from trees.

Layers of coal are the continuous accumulation of layers of trees and plants, and after continuous geological changes, they have entered the underground in different years, and then under the continuous physical and chemical action, they have become today's layers of underground coal!

Primary forests were put into the ground by the movement of the earth's crust and evolved over a long period of time. Wei Liang: This is conclusive in the textbooks, do you still need to doubt it? Conventional wisdom holds that

Coal is formed by the abundant plants and their accumulations in ancient times that were buried in the ground during the changes of the earth's crust and formed through a complex carbonization process of long-term high temperature and high pressure. Oil and petroleum gas (LPG) are formed by the animals, microorganisms and their sediments in ancient lakes and oceans that were buried underground by crustal changes and used by long-term high temperature and high pressure geology. The evidence for this theory is that carbonized specimens such as branches, stems, and leaves of plants have been found in coal.

The thickness of the coal seam in the coal field can reach more than 100 meters, and the coal reserves in a mining area reach hundreds of billions of cubic meters, and the abundance of reserves is breathtaking. So, there is a question, did there exist in history such an abundance of primeval forests? Is there such a large amount of forest that at some point quickly sank into the ground and gathered?

Why is it that there is not a large amount of plant-like reed coal in the coal seam, but a large amount of crystalline lump or pulverized coal? As we all know, the coal quality in Shanxi is good, and the coal crystals are shiny and shiny, and they are very shiny.