The relief is ... The description of the relief. Geological structure and relief

Studying geography and topography, we are faced with such a concept as the terrain. What is this term and what is it used for? In this article, we will understand the meaning of this word, find out what kinds and forms of reliefs there are, and much more.

The concept of relief

So, what does this term mean? The relief is a set of irregularities in the surface of our planet, which are composed of elementary forms. There is even a separate science that studies its origins, history of development, dynamics and internal structure. It is called geomorphology. The relief consists of separate forms, that is natural natural bodies, representing its separate parts and possessing its own dimensions.

Variety of shapes

According to the morphological principle of classification, these natural natural bodies can be both positive and negative. The first of them rise above the horizon line, representing a rise of the surface. As an example, you can bring a hillock, a hill, a plateau, a mountain, and so on. The latter, respectively, form a decrease relative to the horizon line. It can be valleys, beams, hollows, ravines, etc. As already mentioned above, the shape of the relief consists of separate elements: surfaces (faces), points, lines (edges), angles. By the degree of complexity distinguish between complex and simple natural natural bodies. Simple forms include hillocks, hollows, hollows, etc. They are separate morphological elements, the combination of which forms a form. An example is the hillock. It is divided into such parts: sole, slope, top. A complex form consists of a number of simple forms. For example, the valley. It includes the channel, floodplain, slopes and so on.

By the degree of slope distinguish subhorizontal surfaces (less than 20 degrees), inclined and slopes (more than 20 degrees). They can have different shapes - straight, convex, concave or stepped. According to the extent of the stretch, they are usually divided into closed and open.

Types of reliefs

The combination of elementary forms, which have a similar origin and extend in a certain space, defines the type of relief. On significant areas of our planet, it is possible to combine several separate species based on a similar origin or difference. In such cases it is customary to talk about groups of relief types. When the association is made on the basis of their education, they speak of genetic forms of elementary forms. The most common types of land relief are plain and mountainous. In height, the first is divided into depression, elevations, lowlands, plateaus and plateaus. Among the latter, high, high, medium and low are distinguished.

Flat terrain

This area, which is characterized by insignificant (up to 200 meters) relative elevations, as well as a relatively small steepness of the rays (up to 5 degrees). Absolute heights here are small (only up to 500 meters). These parts of the earth's surface (land, bottom of the seas and oceans), depending on the absolute altitude, are low-lying (up to 200 meters), elevated (200-500 meters), upland or high (over 500 meters). The relief of the plains depends primarily on the degree of intersection and soil-vegetation cover. This can be loamy, clayey, peaty, sandy loamy soils. They can be cut by riverbeds, beams and ravines.

Hilly relief

This is a terrain that has a wavy character of the earth's surface, forming irregularities with absolute heights of up to 500 meters, relative elevations of up to 200 meters and a steepness of not more than 5 degrees. Hills are often composed of hard rocks, and the slopes and peaks are covered with a thick layer of loose rock. The lowlands between them are flat, wide or enclosed basins.

Hills

Mountain relief is a terrain that represents the surface of the planet, significantly elevated relative to the surrounding area. It is characterized by absolute heights from 500 meters. Such a territory is characterized by a diverse and complex terrain, as well as specific natural and weather conditions. The main forms are mountain ranges with characteristic steep slopes, which often turn into cliffs and rocks, as well as gorges and hollows located between the ridges. The mountain areas of the earth's surface are essentially raised above the ocean level, while they have a common base, which rises above the adjacent plains. They consist of many negative and positive forms of relief. According to the level of their height, they are divided into low mountains (up to 800 meters), middle mountains (800-2000 meters) and highlands (from 2000 meters).

Formation of relief

The age of the elementary forms of the earth's surface can be relative and absolute. The first establishes the formation of the relief with respect to some other surface (sooner or later). The second is determined using a geochronological scale. The relief is formed due to the constant interaction of exogenous and endogenous forces. So, endogenous processes are responsible for the formation of the main features of elementary forms, and exogenous, on the contrary, tend to align them. In the relief formation, the main sources are the energy of the Earth and the Sun, do not forget about the influence of the cosmos. The formation of the earth's surface occurs under the influence of gravity. The main source of endogenous processes can be called the thermal energy of the planet, which is associated with radioactive decay occurring in its mantle. Thus, under the influence of these forces, a continental and oceanic crust was formed . Endogenous processes cause the formation of faults, folds, movement of the lithosphere, volcanism and earthquakes.

Geological observations

Scientists-geomorphologists are engaged in studying the shape of the surface of our planet. Their main task is to study the geological structure and terrain of specific countries, continents, and the planet. When composing the characteristics of a particular locality, the observer must determine what caused the surface shape before him, to understand its origin. Of course, it will be difficult for a young geographer to independently understand these issues, so it is better to ask for help from books or a teacher. By making a description of the relief, a group of geomorphologists must cross the area under investigation. If you want to map only along the route, you should maximize the observation bandwidth. And in the process of research, periodically move away from the main path to the sides. This is especially important for poorly foreseeable terrain, where the forest or hills interfere with the survey.

Mapping

Writing information of a general nature (hilly, mountainous, strongly crossed, etc.), it is also necessary to map and describe each relief element separately-a steep slope, a ravine, a ledge, a river valley, etc. Determine the dimensions-depth, Width, height, angles of inclination - often have, as they say, by eye. Due to the fact that the relief depends on the geological structure of the terrain, then carrying out observations, it is necessary to describe both the geological structure and the composition of the rocks that make up the studied surfaces, and not just their appearance. It is necessary to note in detail karst craters, landslides, caves, etc. In addition to the description, it is necessary to draw schematic sketches of the studied territory.

By this principle, you can explore the terrain near which your home is located, or you can describe the relief of the continents. The methodology is one, only the scales are different, and more time will be needed to study the continent in detail. For example, in order to describe the relief of South America, it will be necessary to create many research groups, and even then it will take more than one year. After all, this continent is characterized by an abundance of mountains stretching along the whole continent, Amazonian virgin forests, Argentine pampas, etc., which creates additional difficulties.

Note to the young geomorphologist

When plotting a relief map of the locality, it is recommended to ask the locals where it is possible to observe the places where the layers of rock and groundwater escape. These data should be recorded on the terrain and described in detail and sketched. On the plains, rock is most often exposed in places where rivers or ravines cut through the surface and formed bank cliffs. Also, these layers can be observed in quarries or where the highway or railway passes through a cut cut. The young geologist has to consider and describe each layer of rock, it is necessary to start from the bottom. With the help of roulette, you can make the necessary measurements, which should also be recorded in the field book. The description should indicate the dimensions and characteristics of each layer, their sequence number and exact location.