The pear shape is characterized by narrow shoulders, small breasts and wide hips. If this is your body type, check what you should wear and what you should avoid. We will advise you on how to focus on the best. But also skillfully hide any flaws in the figure.
The pear figure is far from uncommon for many of us. However, it is enough to know a few simple techniques, thanks to which we will emphasize the correct proportions of the figure. Before you go shopping, read these stylist tips.
Pear figure - characteristic
The pear figure is one of the most popular body types according to men. Have it, in particular, Jennifer Lopez, Shakira, Katie Holmes, Rihanna. Here are the characteristics of the pear shape:
- small breasts,
- slim waist,
- wide and massive hips,
- slender calves.
Pear figure - what to wear?
One of the most common mistakes with such a figure is wearing wide tunics or sweaters. If you still make this mistake, then it's time to change your wardrobe.
The pear figure, like the hourglass figure, is characterized by a narrow waist. As a result, she is considered the best female trump card. That is why people of this type of uniform must wear appropriate clothing.
Also, you must wear skirts (preferably high-waisted), knee-length or longer dresses, high heels.
However, it is worth paying attention to the details. The blouse is fastened with buttons, ruffles on the neckline, round, square and boat cutouts, embroidered appliques. Beads and beads are materials that can be worn without any problems.
Pear shape - what should you avoid?
If you have a pear figure, you should refuse:
- blouses and jackets reaching the hip line,
- short skirts,
- tight shorts,
- skinny jeans,
- ankle-length coat.
Introduction ………………………………………………………………………… ..2
1. The structure of the Earth …………………………………………………………… .3
2. Composition of the earth's crust ……………………………………………………… ... 5
3.1. State of the Earth ………………………………………………………… .... 7
3.2. The state of the earth's crust ………………………………………………… ... 8
List of used literature …………………………. ………………… 10
Introduction
The Earth's crust is the outer hard shell of the Earth (geosphere). Below the crust is a mantle, which differs in composition and physical properties - it is denser, contains mainly refractory elements. The crust and mantle are separated by the Mohorovichich boundary, or Moho for short, on which there is a sharp increase in the velocities of seismic waves. On the outside, most of the crust is covered by the hydrosphere, and a smaller part is under the influence of the atmosphere.
The crust is found on most of the terrestrial planets, the Moon and many satellites of the giant planets. In most cases, it is composed of basalts. The earth is unique in that it has two types of crust: continental and oceanic.
1. Structure of the earth
Most of the Earth's surface (up to 71%) is occupied by the World Ocean. The average depth of the World Ocean is 3900 m. The existence of sedimentary rocks, the age of which exceeds 3.5 billion years, serves as proof of the existence of vast reservoirs on Earth at that distant time. On modern continents, plains are more common, mainly low-lying, and mountains - especially high ones - occupy an insignificant part of the planet's surface, as do deep-sea depressions at the bottom of the oceans. The shape of the Earth, which is known to be close to spherical, with more detailed measurements turns out to be very complex, even if you outline it with a flat ocean surface (not distorted by tides, winds, currents) and a conditional continuation of this surface under the continents. The irregularities are supported by the uneven distribution of mass in the bowels of the earth.
One of the features of the Earth is its magnetic field, thanks to which we can use the compass. The magnetic pole of the earth, to which the north end of the compass needle is drawn, does not coincide with the geographic north pole. Under the influence of the solar wind, the Earth's magnetic field is distorted and acquires a "trail" in the direction from the Sun, which extends for hundreds of thousands of kilometers.
The internal structure of the Earth, first of all, is judged by the peculiarities of the passage through various layers of the Earth of mechanical vibrations that occur during earthquakes or explosions. Valuable information is also provided by measurements of the magnitude of the heat flux coming out of the interior, the results of determining the total mass, moment of inertia and polar compression of our planet. The Earth's mass is found from experimental measurements of the physical constant of gravity and the acceleration of gravity. For the mass of the Earth, a value of 5.967 1024 kg is obtained. On the basis of a whole complex of scientific research, a model of the internal structure of the Earth was built.
The hard shell of the Earth is the lithosphere. It can be compared to a shell covering the entire surface of the Earth. But this "shell", as it were, cracked into pieces and consists of several large lithospheric plates, slowly moving one relative to the other. The vast majority of earthquakes are concentrated along their borders. The upper layer of the lithosphere is the earth's crust, the minerals of which are mainly composed of silicon and aluminum oxides, iron oxides and alkali metals. The earth's crust has an uneven thickness: 35-65 km on the continents and 6-8 km under the ocean floor. The upper layer of the earth's crust consists of sedimentary rocks, the lower one is basalt. Between them is a layer of granites, which is characteristic only of the continental crust. Under the crust is the so-called mantle, which has a different chemical composition and greater density. The boundary between the crust and the mantle is called the Mohorovich surface. The speed of propagation of seismic waves in it abruptly increases. At a depth of 120-250 km under the continents and 60-400 km under the oceans lies a layer of the mantle called the asthenosphere. Here the substance is in a state close to melting, its viscosity is greatly reduced. All lithospheric plates seem to float in a semi-liquid asthenosphere, like ice floes in water. Thicker areas of the earth's crust, as well as areas consisting of less dense rocks, rise in relation to other areas of the crust. At the same time, the additional load on the crustal area, for example, due to the accumulation of a thick layer of continental ice, as occurs in Antarctica, leads to a gradual subsidence of the area. This phenomenon is called isostatic alignment. Below the asthenosphere, starting from a depth of about 410 km, the "packing" of atoms in mineral crystals is compacted under the influence of high pressure. The abrupt transition was detected by seismic research methods at a depth of about 2920 km. Here begins the Earth's core, or, more precisely, the outer core, since there is another one in its center - the inner core, the radius of which is 1250 km. The outer core is obviously in a liquid state, since transverse waves that do not propagate in a liquid do not pass through it. The origin of the Earth's magnetic field is associated with the existence of a liquid outer core. The inner core appears to be solid. At the lower boundary of the mantle, the pressure reaches 130 GPa, the temperature there does not exceed 5000 K. At the center of the Earth, the temperature may rise above 10,000 K.
2. The composition of the earth's crust
The earth's crust consists of several layers, the thickness and structure of which are different within the oceans and continents. In this regard, oceanic, continental and intermediate types of the earth's crust are distinguished, which will be described below.
According to their composition, three layers are usually distinguished in the earth's crust - sedimentary, granite and basalt.
The sedimentary layer is composed of sedimentary rocks, which are the product of destruction and redeposition of the material of the lower layers. Although this layer covers the entire surface of the Earth, in some places it is so thin that one can practically speak of its discontinuity. At the same time, it sometimes reaches a capacity of several kilometers.
The granite layer is composed mainly of igneous rocks, formed as a result of solidification of molten magma, among which varieties rich in silica (felsic rocks) prevail. This layer, reaching a thickness of 15-20 km on the continents, is greatly reduced under the oceans and may even be completely absent.
The basalt layer is also composed of magmatic matter, but with poorer silica (basic rocks) and a higher specific gravity. This layer is developed at the base of the earth's crust in all regions of the globe.
The continental type of the earth's crust is characterized by the presence of all three layers and is much more powerful than the oceanic one.
The earth's crust is the main object of the study of geology. The earth's crust consists of a very diverse rock, consisting of no less diverse minerals. When studying a rock, first of all, its chemical and mineralogical composition is studied. However, this is not enough for a complete knowledge of the rock. The same chemical and mineralogical composition can have rocks of different origin, and therefore, different conditions of occurrence and distribution.
The rock structure is understood as the size, composition and shape of its constituent mineral particles and the nature of their relationship with each other. There are different types of structures, depending on whether the rock is composed of crystals or an amorphous substance, what is the size of the crystals (whole crystals or their fragments are part of the rock), what is the degree of roundness of the fragments, the mineral grains forming the rock are completely unrelated to each other, or they are soldered by some cementing substance, directly fused with each other, sprouted to each other, etc.
Texture is understood as the interposition of the components making up the rock, or the way they fill the space occupied by the rock. An example of textures can be: layered, when the rock consists of alternating layers of different composition and structure, shaly, when the rock easily disintegrates into thin tiles, massive, porous, solid, bubbly, etc.
The form of bedding of rocks is understood as the shape of the bodies formed by them in the earth's crust. For some rocks, these are strata, i.e. relatively thin bodies bounded by parallel surfaces; for others - veins, rods, etc.
The classification of rocks is based on their genesis, i.e. way of origin. There are three large groups of rocks: igneous, or igneous, sedimentary and metamorphic.
Igneous rocks are formed in the process of solidification of silicate melts located in the bowels of the earth's crust under high pressure. These melts are called magma (from the Greek word for "ointment"). In some cases, magma penetrates into the strata of the underlying rocks and solidifies at a greater or lesser depth, in others it solidifies, pouring out onto the Earth's surface in the form of lava.
Sedimentary rocks are formed as a result of the destruction of pre-existing rocks on the Earth's surface and the subsequent deposition and accumulation of the products of this destruction.
Metamorphic rocks are the result of metamorphism, i.e. transformations of pre-existing igneous and sedimentary rocks under the influence of a sharp increase in temperature, an increase or change in the nature of pressure (change of all-round pressure to oriented), as well as under the influence of other factors.
3.1. State of the Earth
The condition of the land is characterized by temperature, humidity, physical structure and chemical composition. Human activities and the functioning of flora and fauna can improve and degrade land condition indicators. The main processes of impact on land are: irrevocable withdrawal from agricultural activities; temporary withdrawal; mechanical impact; addition of chemical and organic elements; involvement in agricultural activities of additional territories (drainage, irrigation, deforestation, reclamation); heating; self-renewal.
Education
What is the earth's crust made of? Elements of the earth's crust
09 Aug 2017The Earth's crust is the solid surface layer of our planet. It was formed billions of years ago and is constantly changing its appearance under the influence of external and internal forces. Part of it is hidden under water, while the other forms dry land. The earth's crust is made up of various chemicals. Let's find out which ones.
Surface of the planet
Hundreds of millions of years after the emergence of the Earth, its outer layer of boiling molten rocks began to cool down and formed the earth's crust. The surface changed from year to year. Cracks, mountains, volcanoes appeared on it. The wind smoothed them out, so that after a while they would appear again, but in other places.
Due to external and internal processes, the outer solid layer of the planet is heterogeneous. In terms of structure, the following elements of the earth's crust can be distinguished:
- geosynclines or folded areas;
- platforms;
- edge faults and deflections.
The platforms are large, inactive areas. Their upper layer (to a depth of 3-4 km) is covered by sedimentary rocks, which are overlain in horizontal layers. The lower level (foundation) is badly crumpled. It is composed of metamorphosed rocks and may contain magmatic inclusions.
Geosynclines are tectonically active areas where mountain building processes take place. They arise at the junction of the ocean floor and the continental platform, or in the trough of the ocean floor between continents.
If mountains form close to the platform boundary, edge faults and troughs can occur. They reach up to 17 kilometers in depth and stretch along the rock formation. Over time, sedimentary rocks accumulate here and deposits of minerals (oil, rock and potassium salts, etc.) are formed.
Bark composition
The crust mass is 2.8 · 1019 tons. This is only 0.473% of the mass of the entire planet. The content of substances in it is not as diverse as in the mantle. It is formed by basalts, granites and sedimentary rocks.
99.8% of the earth's crust consists of eighteen elements. The rest account for only 0.2%. The most common are oxygen and silicon, which make up the bulk of the mass. In addition to them, the crust is rich in aluminum, iron, potassium, calcium, sodium, carbon, hydrogen, phosphorus, chlorine, nitrogen, fluorine, etc. The content of these substances can be seen in the table:
Item name
Oxygen
Aluminum
Manganese
Astatine is considered the rarest element - an extremely unstable and poisonous substance. Tellurium, indium, thallium are also rare. They are often scattered and do not contain large clusters in one place.
Continental crust
The mainland or continental crust is what we usually call land. It is quite old and covers about 40% of the entire planet. Many of its parts are between 2 and 4.4 billion years old.
The continental crust consists of three layers. From above it is covered by an intermittent sedimentary cover. Rocks in it lie in layers or layers, as they are formed as a result of pressing and compaction of salt sediments or the remains of microorganisms.
The lower and more ancient layer is represented by granites and gneisses. They are not always hidden under sedimentary rocks. In some places, they come to the surface in the form of crystalline shields.
The lowest layer consists of metamorphic rocks like basalts and granulites. The basalt layer can reach 20-35 kilometers.
Ocean crust
The part of the earth's crust hidden under the waters of the World Ocean is called oceanic. It is thinner and younger than the continental one. The crust is less than two hundred million years old, and its thickness is about 7 kilometers.
The continental crust consists of sedimentary rocks from deep-sea remains. Below is the basalt layer 5-6 kilometers thick. Under it begins the mantle, represented here mainly by peridotites and dunites.
The crust is renewed every hundred million years. It is absorbed in subduction zones and re-formed in the mid-oceanic ridges, with the help of minerals coming out.
- a complex of highly specialized cells and tissues located on the outside of the cambium and performing protective and conductive functions. The transport of nutrients formed in the leaves is carried out along the conductive elements of the bark. The bark protects the tree from damage by animals, wood-decaying insects and rotting organisms.
Also protects cambium from moisture loss. In terms of structure and composition, bark differs significantly from wood (xylem). The special role of the green parts of the tree - foliage and needles, associated with the provision of life processes in plants, including woody ones, also leads to certain features of their chemical composition and structure.
Tree bark structure
It makes up a significant share (from 6 to 25%) of the total volume of the tree, depending not only on the tree species, but also on the age of the tree and growing conditions. The larger the trunk diameter, the more bark. With age, the relative volume of tree bark decreases. Deterioration of growing conditions leads to an increase in the proportion of tree bark.
The bark of an adult tree consists of two parts, differing in anatomical structure and functions: the inner part is the bast, or phloem, and the outer part is the crust. The relative content of these parts of the bark depends not only on the tree species, but varies between individual trees of the same species and even within an individual tree. Bast tissues carry juices (solutions of organic matter) down the trunk and store reserve nutrients. Peel fabrics provide protection from external influences. The bark of coniferous trees has a simpler structure compared to the bark of deciduous trees.
Tree bark structure associated with the formation of its tissues from two secondary meristems - cambium and cork cambium (phellogen). When cambium cells divide, along with the formation of xylem cells, bast cells (phloem) appear, which, like xylem cells, differentiate to perform various functions. In the phloem, as in the xylem, although weaker, growth rings 0.1 ... 0.7 mm wide are noticeable with the width of the bast itself usually within 3 ... 10 mm.
In the bast (phloem), there are three types of cells and corresponding tissues: sieve elements that form conductive tissues; parenchymal cells that make up storage tissues; sclerenchymal cells are mechanical tissues. Moreover, compared to xylem, living cells account for a greater proportion.
The most important conductive tissue of the bast consists of sieve elements - sieve cells in conifers and sieve tubes in deciduous trees. Sieve cells are narrow, long cells that form longitudinal rows and communicate with each other through porous sieve fields in the cell walls at their ends. Cytoplasmic filaments pass through numerous small pores.
The conductive bast system of deciduous trees is more perfect. In them, sieve tubes are formed from the cells of the segments, communicating with each other through porous (with larger pores) sieve plates on the transverse walls. Thus, the conductive elements of the bast of conifers resemble early tracheids, and in deciduous trees - vessels, but unlike tracheids and vessels, the sieve elements contain living protoplast (in it only the nucleus and some other organelles are destroyed), and their walls are not lignified. Sieve elements usually die off by the end of the growing season and flatten, and in the next season new elements are formed.
The second type of bast tissue is the bast (phloem) parenchyma, which performs conducting and storage functions and makes up the bulk of the bast tissue. Parenchymal cells with thin non-lignified walls form bast (phloem) rays, which are a continuation of the core rays of the xylem, and a vertical bast parenchyma. In the bast rays of some species (for example, fir) there are horizontal resin passages.
The mechanical function is performed by sclerenchymal cells, which include bast fibers and sclereids. Bast fibers are long cells with sharp ends and thick walls, reminiscent of libriform fibers, but longer. Their cell walls are usually lignified, but to a lesser extent than those of wood fibers, and may not have lignin. The content of bast fibers varies greatly depending on the tree species. As a rule, there are fewer of them in the bast of conifers than deciduous ones, but there are exceptions.
In some non-woody angiosperms (flax, ramie), bast fibers are very long (several centimeters, and sometimes up to 50 cm in ramie). Sclereids, mainly stony cells, are short, wide cells formed from parenchymal cells as a result of thickening of the cell walls and their significant lignification.
The content of such cells is higher in the bark of conifers than in deciduous trees. They also take on the support function. The form of sclereids in different tree species is quite diverse.AT tree barkAs in wood, primary tissues first appear, and then, during cell division of secondary meristems - cambium and cork cambium - secondary tissues are formed, which subsequently die off. Outer part tree bark - the crust - consists mainly of dead tissue and therefore is physiologically inactive.
At the beginning of tree growth from the primary apical meristem, along with the primary lateral meristem - procambismus, the primary integumentary tissues of the epidermis and the primary tree bark located under it, consisting of layers of collenchyma and parenchyma, are formed. In young trees and shoots, the epidermis consists of one row of epidermal cells covered from the outside with a hydrophobic, wax-like substance, cutin. Collenchyma consists of cells with thickened non-lignified walls and performs a supporting (mechanical) function. Primary phloem and primary xylem are formed from procambium as a result of cell division.
By the end of the first growing season, secondary growth begins. The secondary lateral meristem, cambium, is formed from the procambium, and from it, in turn, the secondary xylem and phloem. A thin layer of cork cambium (phellogen) appears under the epidermis, as a result of cell division, new peridermal tissue is formed. The epidermis gradually collapses and is eventually completely replaced by the peridermis, giving rise to the outer covering layer of the bark. The peridermis consists of three layers: cork cambium (phellogen); cork parenchyma (phelloderm); cork fabric (fellam). Phelloderm is formed by division of phellogen cells from the inside, aphellem from the outside. Phelloderm cells are parenchymal cells similar to bast parenchyma cells. Phelloderma is less developed than fella.
The formation process of the peridermis is diverse. In a number of tree species, phellogen continues to function for a long time, ensuring uniform growth of the fellam layer, which leads to the formation of a thick layer of cork instead of the typical crust, such as cork oak and Douglas fir, or to the formation of a smooth elastic outer layer tree bark, as, for example, birch, aspen, fir. The cell walls of the cork (fella) are distinguished by their special structure and composition. They have three layers. The outer layer is lignified, the inner layer consists of almost pure cellulose, and the middle layer contains a substance characteristic of cork tissue - suberin (see below), and suberin layers alternate with layers of cork wax, which ensures the hydrophobicity of the cork. Birch cork tissue cell walls contain betulin, which gives the outer layer of birch bark - birch bark - a characteristic white color.
In most tree species, starting from a certain age, a layer of cork tissue dies off, and in depth tree bark new layers of the periderm are laid. The phloem undergoes changes associated with aging and somewhat resembling the process of heartwood formation. In the outer part of the phloem, the so-called obliteration is observed - flattening of sieve cells or tubes and clogging of their porous plates, as a result of which the primary phloem completely dies off.
The obliterated secondary phloem is interrupted by the emerging layers of new periderm, which have an irregular shape. In this process, phellogen cells are formed as a result of the division of living parenchymal phloem cells that resume meristematic activity. The new layer of phellogen, in turn, gives new layers of phelloderm and fella, followed by the death of cork cells, etc. As a result of this process, a complex heterogeneous complex of tissues is formed, consisting mainly of dead cells, the outer main part of the crust (rhytid). This layer has a characteristic appearance, cut with cracks. In various types of pine, the bark forms scales on the outside. As the trees grow in thickness, the bark from the outside gradually flakes off.
MOU "Secondary school of Novopushkinskoye"
A script for a lesson in geography on the topic:
"What does the earth's crust consist of?"
Prepared and conducted:
Geography teacher
I qualification
2017
Lesson topic: What is the earth's crust made of
Goal: To provide students with an understanding of the variety of rocks and minerals.
Tasks:
1. Continue the formation of ideas about the structure of the earth's crust,
2. Ensure that students master the knowledge of the terms: "minerals", "rocks", the most common rocks, minerals of the Saratov region, the properties of rocks and minerals.
3. Create conditions for the development of speech, the ability to work in a group, draw an analogy between objects and their symbols
4. Promote the development of companionship and understanding in group work.
Lesson type : learning new material
Equipment: collections of rocks and minerals, physical map of the hemispheres, multimedia presentation,Geography. Initial course: Grade 5: a textbook for students of educational organizations / A.A. Letyagin; under the editorship of V.P. Dronov. - M .: Ventana - Graf, 2016.
During the classes:
I .Organizing time (greeting students, checking readiness for the lesson, filling out the weather diary, phenologist's table).
II .Reiteration.
Students carry out a written check in the "Diary of a geographer-pathfinder" (drawing of a diagram of the volcano).
Quiz:
1.The largest massif of the earth's crust (mainland).
2. What is the name of our planet? (Earth)
3. What happens in the sky after rain? (Rainbow)
4. The top layer of soil on which the plants grow? (the soil)
5. What is the name of the line that cannot be reached? (horizon)
6. Ability to find the sides of the horizon? (navigate)
7. He does not know grief, but cries bitterly. (Cloud)
III ... Goal setting.
What is called the lithosphere?
What parts does it consist of?
What is the structure of the earth's crust and mantle?
On the screen in the presentation, the teacher displays minerals and rocks.
Guys, what do you see on the screen (children's answers)
Studying the course "The World Around". You learned that all natural objects are composed of substances. Give examples of substances (children's answers)
IV .Primary development
- Today in the lesson we will get acquainted with the variety of rocks and minerals and learn about the minerals of our area.
Find on page 41 of the textbook what rocks are according to the conditions of education (children's answers)
By origin, rocks and minerals can be divided into igneous, sedimentary, metamorphic. (On the slide in the presentation)
1. Independent work in groups
1 group. Pages 41-42 of the textbook
Igneous rocks were formed as a result of the solidification of magma on the surface and in the depths of the Earth.
Deep
Poured out
2 group pages 42-43 of the textbook
Sedimentary rocks are formed on the Earth's surface as a result of the deposition of rock debris in water and on land.
Sedimentary clastic rocks
Sedimentary chemical origin
Organic sedimentary origin (sandstones, limestones).
Group 3, page 43 of the textbook
Metamorphic rocks are any rocks that have undergone significant changes under the influence of high temperatures and pressures.
Limestone - marble,
Sandstone - quartzite,
Granite - gneiss
2. Workshop in small groups using the collection of rocks and minerals "Properties of rocks and minerals".
3.Rocks and minerals of the Saratov region (in presentation)
Oil, gas, clay, sand, sandstone, phosphorites, peat, oil shale, sodium chloride and potassium salt, gold. limestone, chalk.
4.Fixing the material :
What rocks and minerals of the Saratov region do you know?
What is the structure of the earth's crust?
What groups of origin are rocks and minerals divided into?
What groups are igneous rocks divided into?
What groups are sedimentary rocks divided into?
How are metamorphic rocks formed?
V Lesson summary, grading.
VI ... Reflection They raise a smiley with a different facial expression, which makes it clear whether you liked the lesson or not.
Vii .Homework: Paragraph 8, make a crossword puzzle "Rocks"
(no more than 15 words), page 45 ass 6, video geography, the project "Formation of rocks"
application
Workshop in small groups using the collection of rocks and minerals. "Properties of rocks and minerals"
origin
colour
shine
transparency
hardness