Material about sands and deserts (rather thinking aloud), based on the data that we have today ...

(From the Arabic "sahra" - desert)

Tell me, where do we have the most sand?

That's right .. under water, in the oceans and seas. Deserts, this is the bottom of the seas and oceans. Yes Yes exactly. As a result of movements earth's crust something went down and something went up. But this process took more than one thousand years.

As you know, deserts cover about a third of the planet's land. But, it happens that the desert that you see, in fact, is not a desert at all. Today you will learn about several such places on our planet.

Sahara

Almost the entire north of Africa is occupied by the world's largest desert - the Sahara. Now its territory extends over 9 million square kilometers, and the semi-desert Sahel adjoins from the south. Temperatures in the Sahara reach the extreme 60 degrees, and yet there is life there. Moreover, life in this territory was not only hidden from bright sun behind every grain of sand, leaving freedom only at night. Even 2700 - 3000 years ago, forests grew in this place, rivers flowed and the windows of countless lakes shone.

And about 9,000 years ago, a very humid climate prevailed in the Sahara desert. And for several thousand years it has been home to people, as well as many steppe and forest animals.

Photographer Mike Hetwer has kindly shared his photographs showing what remains of the era of the "green" Sahara desert. (© Mike Hetwer).

During an expedition to search for dinosaur fossils in the state of Niger in West Africa, photographer Mike Hetwer discovered large burial, containing hundreds of skeletons from two different cultures - Kiffian and Tenerian, each of which is thousands of years old. Hunting tools, ceramics and bones of large animals and fish were also found.

An aerial view of the desert and the barely visible tents of a small group of archaeologists excavating. Looking at this photo, it is hard to believe that a few thousand years ago it was the "green" Sahara.

This is a 6,000-year-old skeleton found that, for unknown reasons, had the middle finger in its mouth. At the time of the excavation, the temperature in this part of the Sahara desert was +49 degrees, far from the temperature in the "green" Sahara 9,000 years ago.

Six thousand years ago, a mother and two children died at the same time and were buried here holding each other's hands. Someone took care of them, as scientists discovered that flowers had been placed on top of the bodies. It is not yet known how they died.

This 8,000 year old giraffe rock art is considered one of the finest petroglyphs in the world. The giraffe is depicted with a leash on its nose, which implies a certain level domestication of these animals.

Interestingly, ancient sands can store information. Optical luminescence studies of the sand, produced in a US laboratory, proved that the bottom of this lake was formed 15,000 years ago during the last ice age.

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Most deserts formed on geological platforms and occupy the most ancient land areas. Deserts located in Asia, Africa and Australia are usually located at altitudes from 200-600 meters above sea level, in Central Africa and North America - at an altitude of 1000 meters above sea level. Most deserts border or are surrounded by mountains. Deserts are located either near young high mountain systems (Karakum and Kyzylkum, deserts Central Asia- Alashan and Ordos, South American deserts), or - with ancient mountains (Northern Sahara).

Something unpleasant, perhaps even the terrible word "desert" itself.

She does not leave any hope, resolutely declaring - there is nothing here and cannot be. Here is emptiness, desert. Indeed, if we sum up even those brief information about the desert, which have already been reported, the picture will not be very cheerful. There is no water, several tens of millimeters of rain or snow falls annually, while other regions receive an average of many meters of moisture per year. In the summer it is sizzling heat, forty or even more degrees, and in the shade, and it’s even scary to pronounce it in the sun - the sand heats up to eighty. And mostly very bad soils - sands, cracked clay, limestone, gypsum, salt crusts. For many hundreds of kilometers the desert stretches, no matter how much, it would seem, neither go nor go, all the same lifeless land.

It is hot, there is no water, there is no one for tens of kilometers .. But it is still beautiful.

The insane stuffiness subsides only at night, when the sands cool down.

Sand - well, what is it? - silicon dioxide, that's what it is. Sand from the bottom of the ancient sea - ocean. I don't even know how long the desert was the sea. It's hard to say exactly. There is some kind of panic with dates today. But 12,000 years ago, there was a completely different world here. The drawings on the walls of the cave depict a tropical paradise where people hunted antelopes, hippos, elephants. An abundance of food, thousands of hunters and gatherers - that was what was in this blooming savannah, but not only here.

Photographs taken as proof spaceship Shuttle in different ranges, which show that riverbeds that once stretched throughout the Sahara Desert are buried under the sand.

North Africa was inhabited.

Where did this green world come from? The answer lies outside of this place. earth orbit not stable. In ancient times, a slight deviation of the Earth from its axis caused global changes. One hundred thousand years ago, the deviation was only one degree, but for the Earth this had a disastrous effect. The territory moved a little closer to the sun. And that changed everything...

Five thousand years ago, the earth's axis again deviated from its trajectory, which led to disastrous consequences for the Sahara. The deadly sands returned to the place where life flourished. For the people living here, this was the beginning of the apocalypse. Those who managed to survive moved to the western part of the desert, where the last patch of vegetation remained - the Nile River.

This single source of water supported the lives of the millions of people who settled on its banks. These were the ancient Egyptians. Their great civilization was born as a result of catastrophic climate change.

The Sahara is the largest and hottest desert. Theoretically, there are more than a million trillion grains of sand. This sand seems ordinary, but to the experts it is unique. Sandboarding champions claim that this is the "slipperiest" sand. In addition, it is the oldest sand on the planet.

225 million years ago, the Sahara was much larger.

She was part of a planet that looked completely different than it does now. Almost the entire surface of the world consisted of one continent. It was the ancestor of the Sahara Desert. A huge part of the land area of ​​​​30 million square kilometers was called Pangea. Today, evidence of the existence of this ancient desert is found all over the world, even in places where you least expect to see it.

In this lifeless environment, scientists have made one of the most amazing discoveries in the history of the Sahara. A huge ocean in the middle of the desert. There used to be rivers and lakes, but that was a long time ago. The Sahara Desert was much larger. The discovery began with the discovery of one of the largest creatures on the planet. It was the skeleton of a paralithitan, the largest dinosaur. It weighed approximately 40-45 tons. In addition, irrefutable evidence of the existence of marine life in the vast desert space was found: shark teeth, turtle shells. 95 million years ago, a huge ocean stretched across the territory of North Africa. Scientists call it the Tethys Sea.

Paralytitan

How much did such a giant need to eat in order to maintain himself ..? This indicates that there was plenty of green food in this area.

100 million years ago, the continents were still moving in different directions. Africa gradually separated from the rest of the world.

As soon as it separated, 80 trillion liters of water burst into the vacant space. Water flooded the earth and formed new huge seas.

On the coast, life flourished and for more than 60 million years, the Sahara remained one of the greenest and most fertile places on Earth. But the same forces that gave birth to the Tennis Sea also destroyed it.

As Africa moved across the globe, the continent experienced tremendous tectonic stress. In the blink of an eye, the Tethys Sea flowed north to the Mediterranean. A rapid stream of water formed. Its power cut a channel through the stone, creating a fissure like the Grand Canyon.

This cleft alone will create something that will change the course of human history. The landscape of the Sahara Desert is varied. The line between life and death is very thin. But even here, among 5.5 million km² of sand, there is something amazing - the most fertile arable land.

The banks of the Nile stretch for 3 km. This thin strip provides a population of 1 million people. But the mighty river exists here only thanks to the clash of the forces of nature, which occurred a thousand kilometers to the south of here. Here the monsoons and rains of equatorial Africa move south to meet the snowmelt of the Ethiopian highlands.

Each year, billions of gallons of water overflow the banks of the Nile, flooding the country with valuable silt and minerals, some of nature's best fertilizers.

Outside this area, there is a struggle for survival. Only a few plant species have adapted to desert life. The palm trees have wide, shallow roots that need very little moisture. The grass has thinned leaves, which reduces the evaporation of the precious liquid. Even man has adapted to live in these harsh conditions.

Nomads live in this desert. To survive, they use unique geological structures- oases. Wonderful sources of water hiding among the dunes. In these natural reservoirs there is a liquid that has accumulated here for several million years. This is the most effective method storage of water on the planet.

The secret of oases in the unique sand of the Sahara. Usually, water is quickly absorbed, penetrating deep into the earth through the sand. But the Sahara desert has the smoothest and roundest sand on the planet. Wind-blown for millions of years, the grains of sand are compressed and compacted. This retains moisture and water is not absorbed anywhere.

The Egyptian oases have enough water to supply the Nile River for 500 years. These oases bring the desert to life, but human intervention upsets the delicate balance of desert life.

Once people move here, construction, pollution and Agriculture, destroy the upper layers of the soil, they disappear. Human civilization is increasing pressure on environment changing its balance.

Now the desert is increasing by 80,000 km² per year. This growth is dangerous.

Light sand in the desert reflects heat into the atmosphere. The atmosphere is getting hotter. Clouds are more difficult to form and without rain, the desert becomes even drier. The deadly reflector is global problem, because these events affect people not only in North Africa. Everything that happens in the Sahara affects people living thousands of miles away.

The history of the Sahara is more than just the history of the North African desert - it is the history of our planet. We are just beginning to understand the significance of the complex interconnections that take place in remote parts of the world. But the Sahara plays a central role in Earth's fragile ecology. The clue lies in its location and life-giving properties that can change the whole world.

So where does the sand come from in such quantities?

The origin of deserts can be found out from the geology, hydrogeology and paleogeography of the region, historical information, archaeological work. Satellite images of the Sahara show light-coloured sand spreading in the direction of the prevailing winds from dry valleys. And this is not surprising. Because the main source of sand in the desert is alluvial deposits, river sediments. ( Alluvium (lat. alluviō - "alluvium", "alluvium") - uncemented deposits)

How is sand formed? (Traveling grains of sand)

The ancient Greek philosopher-mathematician Pythagoras somehow puzzled his students by asking them how many grains of sand there are on Earth.

In one of the tales told by Scheherazade to King Shahriyar during 1001 nights, it is said that "the troops of the kings were countless, like grains of sand in the desert." It is difficult to calculate how many grains of sand on Earth or even in the desert. But on the other hand, it is quite easy to establish the approximate number of them in one cubic meter sand. Having calculated, we find that in such a volume the number of grains of sand is determined by astronomical figures of 1.5-2 billion pieces.

Thus, the comparison of Scheherazade was at least unsuccessful, because if the fairy-tale kings needed as many soldiers as there are grains in only one cubic meter of sand, then for this the entire male population would have to be called under arms the globe. Yes, and that would not be enough.

Where did myriad grains of sand come from?

To answer this question, let's take a closer look at this interesting breed.

The vast continental expanses of the Earth are covered with sands. They can be found on the coasts of rivers and seas, in the mountains and on the plains. But especially a lot of sand has accumulated in the deserts. Here it forms mighty sandy rivers and seas.

If we fly in an airplane over the deserts of Kyzylkum and Karakum, we will see an immense sandy sea. Its entire surface is covered with mighty waves, as if frozen "and petrified in the midst of an unprecedented storm that engulfed colossal spaces." In the deserts of our country, sandy seas cover an area exceeding 56 million hectares.

Looking at the sand through a magnifying glass, you can see thousands of sand grains of various sizes and shapes. Some of them have a rounded shape, others differ in irregular outlines.

Using a special microscope, you can measure the diameter of individual grains of sand. The largest of them can be measured even with a regular ruler with millimeter divisions. Such "coarse" grains have a diameter of 0.5-2 mm. Sand, consisting of particles of such sizes, is called coarse-grained. The other part of the sand grains has a diameter of 0.25-0.5 mm. Sand consisting of such particles is called medium-grained.

Finally, the smallest grains of sand have a diameter of 0.25 to 0.05. mm. It can only be measured with optical instruments. If such grains of sand predominate in the sands, then they are called fine-grained and fine-grained.

How are sand grains formed?

Geologists have established that their origin has a long and complex history. The progenitors of sand are massive rocks: granite, gneiss, sandstone.

The workshop in which the process of turning these rocks into sand accumulations takes place is nature itself. Day after day, year after year, rocks are exposed to weathering. As a result, even such a strong rock as granite breaks up into fragments, which are more and more crushed. Part of the weathering products dissolves and is carried away. The minerals most resistant to the action of atmospheric agents remain, mainly quartz - silicon oxide, one of the most stable compounds on the surface of the Earth. The sands may contain feldspars, micas and some other minerals in much smaller quantities. The story of grains of sand does not end there. For the formation of large clusters, it is necessary that the grains turn into travelers.

(I will say right away that this version of scientists does not suit me - scientists are dark, oh they are dark)

This one doesn't work either...

"Where does the sand come from?"- The short answer is that grains of sand are pieces of ancient mountains.

But this one seems to fit:

Desert sand is the result of the tireless work of water and wind. It comes mainly from ancient oceans and seas. For millions of years, waves have rubbed coastal rocks and stones into sand. During the development of the Earth, some seas disappeared, and in their place were huge masses of sand. Winds blowing in the desert separate light river sand from pebbles and often carry it over long distances, and sandy mounds are formed there. Sand can also come from the sandbanks of rivers that used to flow through deserts, or it can be rocks that have weathered and turned into sand.

(Just let's imagine how long it takes to "grind" the rocks so that there is so much sand?)

For the reader to understand where I'm getting at, here's a hint:

Sand is time.

Time of the planet Earth. (since its inception, foundation) +/- (like all watches in the world)

We can say that each grain of sand has its own unique story. Only here is the key to pick up in order to get data from this sand array.

# - If you understand that water was a primary or secondary substance when our world was created, then another substance, the firmament (stone, rock) interacted with water, rubbed, rolled, along the bottom of the seas, oceans, rushed by the wind ..

How much time (millions of years) did it take for water to make a grain of sand out of pieces, fragments of silicon, granite? - and you try to imagine ...

Another version (not mine)

Origin of the Sahara desert and its sand:

Sand in air currents, especially sand carried from the African Sahara across the Atlantic to South America, helps support an astonishing diversity of life in the jungle and the Amazon. And what happened to the Sahara desert, which was depicted in rock art as a territory of lakes, rivers, boats and animals?

From lakes and meadows with hippos and giraffes to a vast desert, North Africa's sudden geographic transformation 5,000 years ago is one of the most dramatic climate changes on the planet. The transformation took place almost simultaneously in the entire northern part of the continent.

Scientists write that the Sahara turned into a desert, almost instantly!

Transformation of North Africa 5,000 years ago is one of the most dramatic climate changes on the planet.

If the Sahara turned into a huge desert a few thousand years ago or so, what event contributed to this - turned the substance into sand or led to the release of huge amounts of sand into this area?

The research team has tracked the region's wet and dry periods over the past 30,000 years by analyzing sediment samples off the coast of Africa. Such deposits consist, in part, of dust blown off the continent over millennia: the more dust accumulated over a certain period, the drier the continent was.

Based on the measurements they made, the researchers found that the Sahara emitted five times less dust during the African Humid Period than it does today. Their results, which show much more significant climate change in Africa than previously thought, will be published in the journal Earth and Planetary Science Letters.

Theories on the origin and formation of sand

The origin and formation of most sand on Earth and in the Sahara comes down to:
Natural - due to erosion or influenced by the atmosphere
Extraterrestrial - massive sand release during planetary interactions (scenario described in Velikovsky's book Worlds in Collision)
Extraterrestrial - Earth's capture of debris/sand from solar system after planetary catastrophes like the capture of satellites.
Creation/transformation of matter by the phenomena of the Electric Universe such as cometary and planetary discharges in the solar system
Formation of the Electric Universe by local geological phenomena?
Bringing from the bowels of the planet (mud storms, etc.)
Still being formed in real time as a result of the phenomena of Electrical Geology in the Electrical Universe?

And here's another interesting suggestion:

The theory of the origin of sand in the context of the Electric Universe

The theory says that in historical times Mars has been involved in hundreds of catastrophic close encounters with Earth.

Immanuel Velikovsky with his theory and book Worlds in Collision: planets, satellites and comets electrically discharge and explode.

Velikovsky's ideas about catastrophes and geology, described in the book Earth in Revolution.

When there is a highly charged object such as a comet heading towards the earth, there will be an electrical discharge between the two bodies prior to its impact, the magnitude of which will be sufficient to destroy the incoming object - thus, everything will end with a hail of sand and the like.

During famous Chicago fire the entire territory of the United States was illuminated by strange lights, accompanied by falling sand and similar phenomena. It happened during the disappearance comet Biela. (1871)

Is it possible that the Earth is covered in debris from recent cosmic catastrophes? Could debris such as large boulders, rocks, rocks, dust and sand that are believed to have originated on Earth actually be extraterrestrial in origin?

Countless tons of rocks bombard the Earth's atmosphere, fragmenting and breaking down into tiny particles of sand. Falling to Earth, they cover vast areas that were once green and fertile lands, turning them into the deserts that we see today.

This and much more suggests that the catastrophic events of the past had a real basis, but were transformed into a kind of symbolic clues. It is also important that our present time, quite possibly, may soon also become only a symbolic hint for the future generation of people.

The Earth is like a magnet, it attracts everything that flies by, in the form of comets, fireballs, asteroids and ... (Well, yes, it’s possible that the version is passable) For millions of years, such an amount of sand could be collected.

And so what do we know?

5,000 years ago, things were different in the Sahara. Greenery was everywhere.. Animals that needed grass, and... Carved in stone (see picture) There is also a sailboat. That is, there was water on which boats floated.

A grandiose event in its scale took place on Earth about 5000 years ago. It's hard to imagine what it was. The term is not as short as ... It remains only to guess .. (build various versions) from space to ..

There is no water, the sailboats crumbled into dust, the animals went closer to water and food. And only sand in an incredible amount, quietly keeps a secret...

Sand is, on the one hand, such a familiar and simple material to everyone, and on the other hand, it is so mysterious and mysterious. You look at him and you can't take your eyes off him.
I'm into an art called sandart. This is a special kind of drawing-animation, but instead of paints, dry sand is used here. During class, I wondered why he was like that.
If you touch, you calm down. I want to examine it, touch its small grains with my fingers. Watch as it moves from hand to hand. The sand is so pleasant to the touch.
In his research work I decided to expand my knowledge of the material I work with. The work is relevant and can be applied at school as additional material to lessons.

Purpose of the study: To study sand: its origin, types, application. Conduct an experiment on creating sand at home.

Tasks:
1. Know what is sand?
2. Get to know different types sand
3.Find out where sand is used?

Research hypothesis: If the sand is chemical compound, is it possible to conduct a chemical experiment on its manufacture at home using improvised materials?

Study plan:
1. Familiarize yourself with information about sand
2. Prepare everything you need for the experiment
3. Conduct experience
4. Draw conclusions

What is sand?
What is sand, everyone can imagine. From a scientific point of view, it is still a bulk material of inorganic origin, consisting of many small grains of sand or fractions, sedimentary rock, as well as an artificial material consisting of rock grains.
Sand is obtained from small particles of minerals that make up rocks, so various minerals can be found in the sand. Mostly quartz is found in sand (substance - silicon dioxide or SiO 2), as it is durable and there is a lot of it in nature.
Sometimes sand is 99% quartz. Other minerals in the sand include feldspar, calcite, mica, iron ore, and small amounts of garnet, tourmaline, and topaz.

1.1. How and from what was sand formed?
Sand is what is left of rocks, boulders, ordinary stones. Time, wind, rain, sun and time again destroyed mountains, showered rocks, crushed boulders, crushed stones, turning them into billions of billions of grains of sand ranging in size from 0.05 mm to 2.5 mm, making sand out of them. Sand is formed where rocks are subject to destruction. One of the main places where sand is formed is the seashore.
The second most common form of sand is calcium carbonate, such as aragonite, which has been created over the past one and a half billion years. various forms life such as corals and shellfish.
What about sand in deserts? Sand from the shore is carried by the wind inland. Sometimes so much sand moves that an entire forest can be covered with sand dunes. In some cases, desert sand has formed as a result of the destruction of mountain ranges. In some cases, in the place of the desert at one time there was a sea, which, retreating thousands of years ago, left sand here.

Classification by features
Sands are classified according to the following criteria:

Density;

Origin and type;

Grain composition;

The content of dust and clay particles,
including clay in lumps;

The content of organic impurities;

The nature of the shape of the grains;

The content of harmful impurities and compounds;

Strength.

River and sea sands have round grains. Mountain sands are sharp-angled grains contaminated with harmful impurities.

Types of sand
natural sand
river sand- this is sand that is mined from the bottom of rivers, characterized a high degree cleaning. It is a homogeneous material with no foreign inclusions, clay impurities and pebbles. It is purified in a natural way - by the flow of water.
The main advantage of river sand is that it is exactly sand, and not a sand mixture with clay, earth, stone particles. Due to long-term natural exposure, sand grains have a smooth oval surface and are approximately 1.5-2.2 mm in size.
River sand is a fairly high-quality, but at the same time quite expensive building material. Extraction of river sand is carried out with the help of special equipment - dredgers. This does not harm the environment at all, but rather helps to clean the riverbeds. The largest river sand is mined in the mouths of dry rivers.
The color palette of the extracted sand is quite diverse, from dark gray to bright yellow. The reserves of this building material in nature are practically inexhaustible.
Everyone knows that in some regions of the Russian Federation
river sand - a source of gold mining

Sea sand- this is sand, which has in its composition (in comparison with other types of sand) the smallest amount of impurities. The purity of sea sand is determined by the place of its extraction, as well as the use of a two-stage cleaning system from foreign inclusions. The first stage of sand cleaning takes place directly at the place of its extraction, and the second stage takes place within special production sites. Considering the high quality of sea sand, it can, without exaggeration, be used in any construction work.

Quarry sand- this is a natural material mined in an open way in quarries. This sand has a fairly high content of clay, dust and other impurities. Quarry sand is cheaper than river sand, which leads to its widespread use. Depending on the cleaning method, it is divided into seeded and washed quarry sand.
Quarry washed sand- this is sand mined in a quarry by washing big amount water, as a result of which clay and dust-like particles are washed out of it. Sand may include various kinds of impurities, such as stones, earth, clay. Mining is carried out by excavators in large open pits. Quarry sand is usually divided according to the size of its constituent grains. It is fine-grained (particles up to two millimeters in size); medium-grained (particles ranging in size from two to three millimeters); coarse-grained (particles ranging in size from two to five millimeters). Quarry sand has a coarser structure compared to river sand.
Quarry seeded sand- this is sifted sand mined in a quarry, cleaned of stones and large fractions.

construction sand
Unlike natural varieties, artificial sands are produced using specialized equipment by mechanical or chemical action on rocks.
In turn, artificial sands are divided into subspecies of sedimentary and volcanic origin.
Building sand can be used as a universal basis for the manufacture of a variety of building materials and cement mortars. Such a wide range of applications is primarily due to one of the specific qualities of this material: porosity.
Artificial sand has many advantages compared to natural sand, but there are also disadvantages, namely: in addition to the relatively high price, artificially produced sand may have a higher radioactivity.
perlite sands- produced by heat treatment from crushed glass of volcanic origin, called perlite and obsidian. They are white or light gray in color. Used in the manufacture of insulation elements.
Quartz. Sands of this type are also commonly called "white" because of the characteristic, white-milky shade. However, the more common varieties of quartz sands are yellowish quartzes, which contain a certain amount of clay impurities.
In comparison with sands of natural origin, this material compares favorably with its uniformity, high intergranular porosity, and, consequently, dirt holding capacity.
Quartz sand is mined in quarries. Quartz sand is used to create silicate bricks and silicate concretes, fillers for polyurethane and epoxy coatings, which gives them strength and high wear resistance.
Thanks to its versatility and high quality sand of this type is widely used in various industries industry, including water treatment systems, glass, porcelain, oil and gas industry, etc.
Marble. It is one of the rarest species. It is used for the manufacture of ceramic tiles, mosaics, and tiles.

Sand application
Widely used in building materials, building site preparation, sandblasting, road construction, embankment, residential backfilling, yard landscaping, masonry mortar, plastering and foundation work, used for concrete production . In the production of reinforced concrete products, concrete of high strength grades, as well as in the production of paving slabs, curbs.
Fine building sand is used to prepare mortars.
Sand is also used in the manufacture of glass, but only one of its types is quartz sand. Almost entirely it consists of silicon dioxide (quartz mineral). The purity and uniformity of the sand make it possible to use it in the glass industry, where the absence of the slightest impurities is important.
Less pure quartz sand is used in plastering (internal and external) finishing works. Its use in the production of concrete and bricks allows you to give the resulting product the desired shade.
Building river sand is quite widely applicable in various decorative (mixed with various dyes to obtain special structural coatings) and finishing works of the finished premises. It also acts as a component of asphalt mixtures, which are used in the construction and laying of roads (including for the construction of airfields), as well as in the processes of filtering and water purification.
Quartz sand is used for the manufacture of welding consumables for special and general purposes.
Agriculture: Sandy soils are ideal for crops such as watermelons, peaches, nuts and their excellent characteristics make them suitable for intensive dairy farming.
Aquariums: It is also an absolute must for marine reef aquariums, which emulates the environment and consists mainly of aragonite corals and clams. The sand is non-toxic and completely harmless to aquarium animals and plants.
Artificial reefs: sand can form the basis for new ones
reefs. Beaches: governments move sand to beaches where
tides, eddies, or deliberate changes coastline destroy the original sand.
Sand (Sand) is Sandcastles: Shaping sand into castles or
other miniature buildings are popular in towns and on the beach.
Sand Animation: Animated Film Makers Use
sand with front or back illuminated glass. How I do it too.

Practical part
Our task was: is it possible to make silicon dioxide at home.
For the experiment I will need:

silicate glue;

vinegar 70%;

capacity 2 pieces or molds;

syringe;

apron, gloves.

Safety precautions must be observed - vinegar is an acid. We carry out the experiment in a room with open windows, because the vinegar smells sharply. Don't bend over, sniff, or try anything. We put on protective gear.
I take silicate glue. I carefully pour about 1/3 into the container.
Then I take the vinegar and pour it into another container. About the same 1/3.
I use a syringe to draw the vinegar out of the container. I take about 10 ml.
Very carefully pour the vinegar into the glue.
There is a reaction. The glue turns into a gel and hardens. With a stick, carefully mix the glue with vinegar.
I got Silicon Dioxide (SiO2) - a substance consisting of colorless crystals with high strength, hardness and refractoriness.
In nature, silicon dioxide is quite widespread: crystalline silicon oxide is represented by such minerals as jasper, agate, rock crystal, quartz, chalcedony, amethyst, morion, topaz.
You can mix vinegar, glue and food coloring of any color. Get colored silicon dioxide.

MUNICIPAL BUDGET PRESCHOOL EDUCATIONAL INSTITUTION "KINDERGARTEN № 61" FLAG" OF THE CITY OF SMOLENSK

NOD NGO "POZNANIE" IN THE MIDDLE GROUP

"Where does the sand come from?"

Educator of the highest qualification category

Target: Experience the formation of sand in nature.

Material: model of the desert, model of the coast, Lump sugar, plate, table spoon, candle, water in a jug, pipette. Cocktail straws, magnifying glasses for each child. Presentation.

Organization. Sitting and standing around the table.

STUDY PROCESS

Guys, the weather is bad today, it's raining outside and we won't go for a walk. I prepared sand for you to play in a group, and it disappeared somewhere. There is very little left, nothing can be built from it. Too bad we can't play now. Here the toys are small, but there is no sand. And so I wanted to play. What to do? Don't know. Where do you think you can get sand? (Answers). In the sandbox, on the river, on the beach, in the desert...

Why is there so much sand? (Answers) Let's turn to our computer Robitoks, what will he tell us about this, where does the sand come from?

Sand is the particles of rocks that make up the soil. The sand is obtained

when a stone breaks up - under the influence of water, weather conditions, glaciers.

Let's check it out, shall we?

Experience 1. (demo) How sand is formed.

• Here is a piece of sugar. Can we say that it looks like a stone? Yes, he is just as strong. Even if you squeeze it hard, it won't break. And what will happen to him if drops of water fall on him? The water seeps into the cube and breaks the bonds that hold the sugar particles together, and it collapses, breaks. With stones, everything is the same only more slowly.

Conclusion: Under the influence of water, the stones are destroyed.

• Not only water destroys stones, but also the sun. You know the sun is very hot. See what happens to a piece of sugar when it is heated. (Answers) That's right, it begins to melt, melt.

What happens to its form? She starts to change. Similarly, stones.

Conclusion: under the influence of the sun, the stones are destroyed, change their shape.

• But here the sun hid, it became cool. What's happening? (Answers) The sugar stone has hardened. What happened to his form? She has changed. And how did the stone-sugar change in general? (Answer) Yes, the color has changed. And what else? Is it the same thickness? (Answer) No, different, somewhere thicker, and somewhere thinner. In some place, the stone becomes brittle, it can easily break. The same happens with stones.

Robitox still wants to tell us something.

There are two places where you can find the largest deposits

sand, these are deserts, sloping sea shores, where beaches are usually found.

Experience 2. Here is my model of the desert.

• Take straws and blow on the sand. What happened? (Answers) He scattered, moved. Sand waves formed on it, sand mounds appeared.

Not all deserts have the same sand, some have only stones.

• And if a strong wind blows, what happens to grains of sand, stones? (Answers) They scatter, hit each other. Do you think they can break if hit hard? (Answer) They can. Here we proved to swami that sand can be obtained by weathering.

Conclusion: Under the influence of wind, the stones are destroyed. The wind carries the sand, forming sandy waves and hills.

Physical education minute. Let's play a little.

Quietly splashing water

We are sailing on a warm river. (Swimming movements with hands.)

Clouds in the sky like sheep

They fled, who went where. ( Stretching - arms up and to the sides.)

We get out of the river

Let's take a walk to dry off. ( walking in place.)

And now a deep breath.

And we sit on the sand. (Children sit down.)

If the soil consists mainly of sand, its large grains are not able to hold water and nutrients necessary for plants. This is one of the reasons why you won't see many plants either in the desert or on the beach. Deserts are practically open to weathering.

It is not always hot in the deserts, sometimes it rains there, and not just rains, but heavy downpours. And on the coasts there are ebbs and flows.

Experience 3. (demo) Here I have a coast model with a sandy beach. Pieces of plasticine - rocks. The part of the model filled with sand is the beach. The rest I will fill with water. With a piece of cardboard, I will represent the waves. What happens to the sand? (Answers) Water washes away sand and rocks and stones remain visible. And you already know what happens to stones under the influence of water. What's happening? (Answer) They collapse and turn into sand. And water flows carry sand particles around the world.

Conclusion: Stones are destroyed under the influence of water and turn into sand.

Experience 4. What the sand looks like. Take magnifying glasses and review it. Can be hand sprinkled. Can you tell me what sand looks like? What do sand grains look like? Are the grains of sand similar to each other? (Answers) Do grains of sand stick to each other? (answers) no grains of sand stick to each other.

If you carefully look at a handful of sand, you can see that the grains of sand have a different color. This is because sand is formed from several rocks. various kinds. Sand can appear brown, yellow, white, or even black (if it was formed from a certain volcanic rock). On some beaches, the sand may contain grains of organic origin, the source of which is the remains of living things, such as corals, shells, and not rocks.

Conclusion: sand consists of small multi-colored grains that do not stick together.

This is where we played. And not just played, but learned a lot of interesting things about the sand. What did you find most interesting and what do you remember the most? (Answers) Well done. Get medals "The most inquisitive child"