Where does the sand and soil on Earth come from?

The sand of the earth. Some are the Earth formed on the ground (interstellar dust). Part of it is the history of the earth.

In the long river, the rocks are weathered and washed by the current. You can walk up the river, and you will find that the upper reaches of the river are very rocky, and the downstream is sand and mud!

After the weathering of the sand rock, it is carried by the transportation of wind or water flow, the small mass is taken away and deposited to form the soil - plain, the medium quality is carried away when the wind speed or flow rate decreases and the sediment is deposited to form a beach (the soil is carried farther when the carrier speed drops lower, and the gravel is deposited in advance), and the large mass remains in place and continues to weather. In the end, it turned into soil, and that's how the soil on Earth is now formed. Of course, there are also phenomena of magma eruptions forming rocks, although there are far fewer volcanoes today than in ancient times.

The sand used today is made up of minerals and tiny rock fragments, which are brought from the sand field, where the sand gathers. Rock chips are rocks that have been eroded and weathered. The composition of the sand varies from place to place, depending on the local rocks** and conditions.

In inland (e.g., desert) and nontropical coastal (e.g., sandy) environments, the most common component of sand is silicon (silica SiO2). Typically, silicon exists in the form of quartzite.

Feldspar sandstone is a type of sand or sandstone with a high content of feldspar (aluminum silicate) and is usually formed by weathering and erosion of nearby granite.

The fine white sand found in coral reefs is above-ground corals (limestone) that can pass through the digestive system of parrot fish.

In some places, the sand contains magnetite, clay, chlorite, glauconite, or gypsum. Magnetite-rich sand has a deep black color. Sand containing chlorite and glauconite is generally green in color.

The gypsum dunes at the National Museum of White Sands in New Mexico are world-famous for their white color. Earth.

Soil is a variety of sediments produced by rocks undergoing physical, chemical, and biological weathering, as well as denudation, transport, and sedimentation. The solid phase of soil is mainly composed of a variety of mineral particles of different sizes and shapes, and for some soils, in addition to mineral particles, it also contains organic matter.

The size and shape of solid particles, mineral composition and composition of soil have a great influence on the physical and mechanical properties of soil!

Sandy soil refers to soil that is made up of a mixture of more than 80% sand and less than 20% clay. Generally refers to soil with a lot of sand. This kind of soil is loose and has good water permeability and air permeability, but it has poor water and fertilizer retention ability, and needs to be improved when cultivating. Not suitable for the growth of certain plants.

The formation of sand has both natural and human factors, and the human factor is the main one. The loose sandy sediments on the surface are the soil-forming parent material of sandy soils. The soil-forming process occurs under the opposition and unity of wind erosion, sand burial and leaching processes and biological sand fixation and nutrient aggregation processes in the semi-humid climate.

Its formation is characterized by weak soil-forming action, which is often interrupted by wind erosion and sand pressure, and it is difficult to form a complete soil profile. Keep the parent state for a long time. The organic matter content of sandy soil is small, the soil is barren and thin, the moisture is insufficient, and the water leakage and fertilizer leakage are good, but the tillage is good, the boom is hot, and the permeability is strong.

Its agricultural use is mainly to grow crops and pastures in places where sandy land is fixed and there is a certain degree of soil development.

A recent review published in the British journal Nature said that the current rate of sand and gravel mining has exceeded the rate of its natural recovery, which means that the earth is almost out of sand, so how does the sand on the earth come from? What is sand used for?

Sand comes from many places and is formed when rocks decompose over thousands or even millions of years due to weathering and erosion. After the weathering of the rock, it is carried by the transportation of wind or water current, the small mass is taken away and deposited to form the soil - plain, the medium mass is taken away when the wind speed or flow rate decreases and the sediment is deposited to form a beach (the soil is carried farther when the carrier speed drops lower, and the gravel is deposited in advance), and the large mass remains in place and continues to be weathered.

Other biological by-products can also produce sand, for example, Hawaii's white sand beaches actually come from the feces of parrotfish, which use parrot-like beaks to bite off rocks and dead corals, crush the calcium carbonate reef material (mainly made from coral bones), and then expel it as sand.

The role of sand.

The sand has the characteristics of being small, soft, and can be arbitrarily shaped after adding water, and can be used to fill the gaps in the building stones. The bunkers in the long jump have a cushioning effect and protect the athletes; Sandbags can be used for exercises, boxing, kicking, etc.; mixed with lime and cement to build walls; Chickens eat to help with digestion; sandpaper; an hourglass for timekeeping; It can also be used to make jars, such as sand pots.

After the rock is weathered, it is carried by the transportation of wind or water flow, the small mass takes away the sediment to form the soil that is, the plain, the medium quality takes away the sediment when the wind speed or flow speed decreases to form a beach, and the soil is brought to a farther place when the carrier speed decreases, and the gravel is deposited in advance, and the large mass stays in place to continue the wind, and the final outcome is to become sand.

The Gobi is the source of the sand, the most basic material needed for desert expansion, and is usually included in the Gobi, where the extreme dryness and the huge temperature difference between day and night allow the wind to blow the sand away, so that the desert can continue to expand and extend.

Drought is also a factor in the formation of deserts, because the rotation of the earth has caused this area to be shrouded in the downdraft of the atmospheric circulation for a long time, which destroys the process of rainfall, forming an arid climate, and then forming vast deserts.

Soil is formed by weathering of various rocks.

Rocks are naturally occurring assemblages of minerals or glasses with a stable appearance, which are combined in a certain way. It is the material basis that makes up the earth's crust and upper mantle. According to the genesis, it is divided into magmatic rocks, sedimentary rocks and metamorphic rocks.

Among them, magmatic rocks are rocks formed by the condensation of high-temperature molten magma on the surface or underground, also known as igneous rocks or ejecta rocks. Sedimentary rocks are rocks formed by the transport, sedimentation and diagenetic consolidation of the products of weathering, biological and volcanic processes under surface conditions through the transport, sedimentation and diagenetic consolidation of external forces such as water, air and glaciers. Metamorphic rocks are pre-formed magmatic rocks, sedimentary rocks or metamorphic rocks that are formed by metamorphism due to changes in the geological environment in which they are located.

The Earth was formed by the impact of countless interstellar dust, which was originally loaded with earth, stone, and various elements.

Soil is a mixture, the main component is the weathered particles of rocks can be divided into clay, silt, sand, pebbles, etc., other components include: humus, air, water, salt... Wait.

I think it's the dust in the universe that was concentrated together by the gravitational pull of each other before the atmosphere formed.

The amount of sand cannot be calculated from the data.

It is impossible to illustrate this answer with a simple model calculation: if we consider each grain of sand as a cube with a side length of millimeters), then its volume is Note: x n is the nth power of x), i.e. 10 -12 m 3.

That is, under this model, 1 cubic meter of sand is about 10 12, or 100 billion, and even if you take 100 billion as an accurate scale, you can't estimate how many squares of sand there are on the earth (even if you can calculate the total amount of sand on the surface, you can't calculate below the surface). So you ask for single-digit accuracy, that's impossible.