Geological science of soils. Geological Sciences

Geology is the science of the composition, structure and patterns of development of the Earth, other planets of the solar system and their natural satellites.

History of Geology

The study of the physical materials (minerals) of the Earth dates back at least to ancient Greece, when Theophrastus (372-287 BC) wrote Peri Lithon (On Stones). During the Roman period, Pliny the Elder described in detail many minerals and metals, and their practical use, and also correctly identified the origin of amber.

Some modern scholars, such as Fielding H. Garrison, believe that modern geology began in the medieval Islamic world. Al-Biruni (973-1048 CE) was one of the first Muslim geologists, whose works contain early description geology of India. He suggested that the Indian subcontinent was once a sea. Islamic scholar Ibn Sina (Avicenna, 981-1037) proposed detailed explanation the formation of mountains, the origin of earthquakes and other topics that are central to modern geology, and which contains necessary foundation for the further development of science. In China, the encyclopedist Shen Kuo (1031-1095) formulated a hypothesis about the process of land formation: based on observations of fossil animal shells in a geological layer in the mountains hundreds of kilometers from the ocean, he concluded that the land was formed as a result of mountain erosion and sedimentation of silt.

Niels Stensen (1638-1686) is credited with the three defining principles of stratigraphy: the principle of superposition, the principle of primary horizontality of layers, and the principle of the sequence of formation of geological bodies.

The word "geology" was first used by Ulysses Aldrovandi in 1603, then by Jean André Deluc in 1778, and introduced as a fixed term by Horace Benedict de Saussure in 1779. The word comes from the Greek ??, meaning "Earth" and ?????, meaning "teaching". However, according to another source, the word "Geology" was first used by the Norwegian priest and scientist Mikkel Pederson Escholt (1600-1699). Esholt first used the term in his book entitled Geologica Norvegica (1657).

Historically, the term geognosy (or geognostics) was also used. This name for the science of minerals, ores, and rocks was proposed by the German geologists G. Füchsel (in 1761) and A. G. Werner (in 1780). The authors of the term designated the practical areas of geology that studied objects that could be observed on the surface, in contrast to the then purely theoretical geology, which dealt with the origin and history of the Earth, its crust and internal structure. The term was used in specialized literature in the 18th and early XIX century, but began to fall out of use in the second half of the 19th century. In Russia the term was preserved until late XIX century in the titles of the academic title and degree “Doctor of Mineralogy and Geognosy” and “Professor of Mineralogy and Geognosy”.

William Smith (1769-1839) drew some of the first geological maps and began the process of ordering rock strata by studying the fossils they contained.

James Hutton is often regarded as the first modern geologist. In 1785 he presented a paper to the Royal Society of Edinburgh entitled "The Theory of the Earth". In this article, he explained his theory that the Earth must be much older than previously thought in order to provide sufficient time for mountains to erode, and for sediments to form new rocks on the sea floor, which in turn , were raised to become dry land. In 1795 Hutton published a two-volume work describing these ideas (Vol. 1, Vol. 2).

Hutton's followers were known as Plutonists, due to the fact that they believed that some rocks were formed by volcanic activity and resulted from the deposition of lava from a volcano, in contrast to the Neptunists, led by Abraham Werner, who believed that all rocks settled from a large ocean whose level has gradually decreased over time.

Charles Lyell first published his famous book, The Principles of Geology, in 1830. The book, which influenced the ideas of Charles Darwin, successfully promoted the spread of actualism. This theory states that slow geological processes have occurred throughout Earth's history and are still occurring today, as opposed to catastrophism, a theory that states that features of the Earth are formed in a single, catastrophic event and remain unchanged thereafter. Although Hutton believed in actualism, the idea was not widely accepted at the time.

Most 19th century geology revolved around the question of the exact age of the Earth. Estimates ranged from 100,000 to several billion years. At the beginning of the 20th century, radiometric dating made it possible to determine the age of the Earth, the estimate was two billion years. Understanding this vast span of time has opened the door to new theories about the processes that shaped the planet.

The most significant achievement of geology in the 20th century was the development of the theory of plate tectonics in 1960 and the clarification of the age of the planet. The theory of plate tectonics arose from two separate geological observations: seafloor spreading and continental drift. The theory revolutionized geosciences. The Earth is currently known to be about 4.5 billion years old.

In order to awaken interest in geology, the United Nations declared 2008 the “International Year of Planet Earth.”

Sections of Geology

In the process of development and deepening of specialization in geology, a number of scientific directions (sections) were formed.

The branches of geology are listed below.

• Mineral geology studies the types of deposits, methods of their search and exploration.
• Hydrogeology is a branch of geology that studies groundwater.
• Engineering geology - branch of geology that studies interactions
• geological environment and engineering structures.
• Geochemistry is a branch of geology that studies chemical composition of the earth, processes that concentrate and disperse chemical elements in various spheres of the Earth.
• Geophysics is a branch of geology that studies the physical properties of the Earth, which also includes a set of exploration methods: gravity prospecting, seismic prospecting, magnetic prospecting, electrical prospecting of various modifications, etc.
• The following branches of geology study the Solar System: cosmochemistry, cosmology, space geology and planetology.
• Mineralogy is a branch of geology that studies minerals, questions of their genesis, and qualifications. Lithology is the study of rocks formed in processes associated with the atmosphere, biosphere and hydrosphere of the Earth. These rocks are not quite accurately called sedimentary rocks. Permafrost rocks acquire a number of characteristic properties and features studied by geocryology.
• Petrography is a branch of geology that studies igneous and metamorphic rocks primarily from a descriptive perspective - their genesis, composition, textural and structural features, as well as classification.
• Petrology is a branch of geology that studies the genesis and conditions of origin of igneous and metamorphic rocks.
• Lithology (Petrography of sedimentary rocks) is a branch of geology that studies sedimentary rocks.
• Geobarothermometry is a science that studies a set of methods for determining the pressure and temperature of formation of minerals and rocks.
• Structural geology is a branch of geology that studies disturbances in the earth's crust.
• Microstructural geology is a branch of geology that studies the deformation of rocks at the microlevel, on the scale of grains of minerals and aggregates.
• Geodynamics is a science that studies processes on the most planetary scale as a result of the evolution of the Earth. She studies the connection between processes in the core, mantle and crust.
• Tectonics is a branch of geology that studies the movement of the Earth's crust.
• Historical geology is a branch of geology that studies data on the sequence of major events in the history of the Earth. All geological sciences, to one degree or another, are historical in nature, consider existing formations from a historical perspective and are primarily concerned with elucidating the history of the formation of modern structures. The history of the Earth is divided into two major stages - eons, according to the appearance of organisms with solid parts, leaving traces in sedimentary rocks and allowing, based on paleontological data, to determine the relative geological age. With the appearance of fossils on Earth, the Phanerozoic began - the time of open life, and before that there was cryptozoic or Precambrian - the time of hidden life. Precambrian geology stands out as a special discipline, as it studies specific, often strongly and repeatedly metamorphosed complexes and has special methods research.
• Paleontology studies ancient life forms and deals with the description of fossil remains, as well as traces of the vital activity of organisms.
• Stratigraphy is the science of determining the relative geological age of sedimentary rocks, the division of rock strata, and the correlation of various geological formations. One of the main sources of data for stratigraphy is paleontological definitions.
• Geochronology is a branch of geology that determines the age of rocks and minerals.
• Geocryology is a branch of geology that studies permafrost.
• Seismology is a branch of geology that studies geological processes during earthquakes and seismic zoning.
• Volcanology is a branch of geology that studies

Basic principles of geology

Geology is a historical science, and its most important task is to determine the sequence of geological events. To accomplish this task, a number of simple and intuitively obvious signs of the temporal relationships of rocks have been developed since ancient times.

Intrusive relationships are represented by contacts between intrusive rocks and their host strata. The discovery of signs of such relationships (hardening zones, dikes, etc.) clearly indicates that the intrusion formed later than the host rocks.

Cross-sectional relationships also allow one to determine relative age. If a fault breaks rocks, it means it formed later than they did.

Geology is a complex of sciences about the composition, structure, and history of the development of the earth’s crust and the Earth as a whole.

Geology:

Direct methods- Rock sample being examined in laboratory conditions, experiments are carried out, measurements; drilling the earth's crust. (The largest drilling on the Kola Peninsula 80-90, 1500 m, 12.5 km)

Indirect methods- Study of air pollution with the help of plants, study of atmospheric air, x-rays,

Geology object- is the solid shell of the earth “lithosphere” - stone.

Subject of Geology– a system of geological processes in the lithosphere.

Methods for studying geology:

Geochemical – study of rocks using chemical analysis (macroscopic)

Geophysical - the study of the structures of our planet using physical parameters.

Paleontological - the study of the relative age of sedimentary strata of the earth's crust.

Aerospace

Computer modeling and other information methods

The method of actualism or the method of thinking.

The essence of the thinking method: under similar conditions, geological processes follow a similar process. Therefore, by studying modern processes, one can judge how similar processes took place in the distant past. Modern processes can be observed in nature (volcanic eruptions, or created artificially by exposing rock samples to high temperatures and pressure). However, the geological and geographical situation in historical path has changed irreversibly and we cannot always have a completely objective idea of ​​the conditions that existed on our planet in the past. Therefore, the older the study of the thickness, the more limited the application of the method of relevance.

Structure and composition of geological science.

Structure of geological science:

Descriptive (statistical)

Dynamic (dynamic)

Historical (retrospective)

Composition of geological science:

Geophysics- a complex of sciences that study by physical methods structure of the earth, its physical properties and processes occurring in its shells.

Geochemistry - a science that studies the chemical composition of the Earth, the prevalence of chemical elements and their isotopes in it, the pattern of distribution of chemical elements in various geospheres, the laws of behavior, the combination and migration of elements in natural processes.

Geodynamics- a branch of geology that studies the forces and processes in the crust, mantle and core of the Earth that determine deep and surface masses in time and space.

Tectonics- a branch of geology that studies the development of the structures of the earth's crust, its changes under the influence of tectonic movements and deformations associated with the development of the Earth as a whole.

Mineralogy– the science of minerals, their composition, properties, features and patterns of physical structure, conditions of formation, location and study in nature.

Petrography (petrology)– the science of rocks and their mineralogical composition, chemical composition, structure and texture, conditions of occurrence, patterns of distribution, origin and study in the earth's crust and on its surface.

Lithology– the science of sedimentary rocks and modern sediments, their material composition, structure, patterns in the conditions of formation and change.

Paleontology– science of extinct things living organisms, preserved in the form of fossil remains, imprints and traces of life, about their change in space and time, about all manifestations in life in the geological past that are accessible to study.

Hydrogeology– the science of groundwater, studying its composition, properties, origin, patterns of distribution and movement, as well as interaction with rocks.

Engineering geology– processes and phenomena, properties of soils on which engineering structures are erected.

Geocryology– a science that studies the composition and structure, properties, origin of distribution and history of the development of frozen strata in the earth’s crust, as well as the processes associated with their freezing and thawing.

The place of geology in the system of natural sciences.

Among the natural historical sciences, geology occupies a prominent position and is closely related to other natural historical sciences. When studying the mineral changes of the Earth, geology comes into contact with chemistry, physics, mineralogy and even astronomy, especially when analyzing the question of the origin of the Earth. In the study of organized fossil remains, geology comes into close relationship with botany and zoology. When studying past changes on the earth's surface, it comes into close connection with physical geography, and when studying modern geological phenomena, it is not so much interested in their causality as in the results that these phenomena leave on the earth's surface. Geology has introduced a new element not only into the field of natural sciences, but also into the vast field of human knowledge. A mineralogist, botanist or zoologist, studying finished products of nature, i.e. a mineral, plant or animal, may be indifferent to the time when this product of nature appeared on Earth. But the geologist opens up the possibility, when sequentially analyzing the monuments of Earth's life, to mark those pages on which the occurrence of a given mineral or organism is more or less clearly recorded. You can follow its stay on the earth's surface on the following pages of monuments to the life of the Earth and, finally, you can note the moment when a given organism either completely disappears from the face of the Earth or is replaced by a new one.

Geology introduced a new element into the sciences - time, which makes it possible to embrace the economy of nature with a broader spiritual gaze and show how long and consistent was the path by which the nature around us developed. Here, of course, a parallel can be drawn with the humanities, for which human history is the same cornerstone as geology is for the natural history sciences. Geology, in addition, has provided a wealth of material that is completely new from the point of view of classification. For example, we can take zoology. For a long time single-hoofed animals were completely isolated among other mammals, and their genetic connection was thus lost. Only thanks to geological finds was it possible to prove with sufficient clarity and consistency that single-hoofed animals are closely genetically related to other odd-toed animals, in their modern organization, which have so little in common with single-hoofed animals. If we take into account the mass of fossil organisms, both aquatic and terrestrial, that have already disappeared from the face of the Earth, geology has discovered, and if we pay attention to the so-called embryonic and composite types, then it becomes quite clear that botany and zoology owe this science their modern classifications.

When analyzing the newest pages of the life of the Earth, geology also comes into contact with the history of mankind. When producing peat, products made from stone with rough or more or less perfect upholstery, bronze and iron products have long been extracted from the bogs of Denmark. Consistent geological analysis of the peat layering revealed that these remains are distributed in it with a certain sequence: stone products are distributed in the lower layers, bronze - in the middle and iron - in the upper. This gave rise to the establishment of the Stone, Bronze and Iron centuries in the course of the culture of prehistoric man in Western Europe. But they were not content with this and tried to restore the nature of that time using the remains of plants in the peat. It turned out that the dominant tree species during the life of Stone Age man was pine, Bronze Age - oak and Iron Age - beech. This vertical distribution of woody vegetation makes it possible, from a comparison with the modern distribution of plants on Earth, to come to the conclusion that significant climatic changes have occurred since Stone Age man lived on Earth and that at that time the climate in Denmark was much harsher than it is now. Denmark is known from ancient Roman news: it is constantly mentioned there as the dominant tree species- beech; Consequently, the Romans also found beech trees in this country; and when there were oak forests or pine forests that preceded them - this is lost in ancient times, of course, not only not captured by human history, but also long before the time of the epic. Finally, finds of even more ancient human remains - contemporary with the mammoth and the Siberian rhinoceros - should be lost in even more distant times.

The structure of the Earth and the picture of nature in the minds of ancient thinkers.

The main stages in the development of geological knowledge.

The origins of geological knowledge date back to ancient times and are associated with the first information about rocks, minerals and ores. Even in ancient times, the ability to find, extract and use valuable materials in the earth's crust, including various metals, was extremely highly valued. Thus, the initial geological information obtained by people was closely interconnected with the process of using the earth's crust.

Ancient Greek thinkers: Thales of Miletus, Xenophanes of Colophon, Heraclitus of Ephesus, Aristotle, Theophrastus(or Theophrastus, or Tirthamos, or Tirtham) hundreds of years before new era in their writings they tried to explain earthly processes with real processes.

Heraclitus of Ephesus(530-470 BC) argued that the world is eternal, that it is constantly changing and in it the processes of creation are periodically replaced by processes of destruction.

Aristotle(384-322 BC) drew attention to fossils as the remains of extinct organisms. Already in ancient Greece, two main interpretations of the nature of geological phenomena emerged, later called plutonism and neptunism.

Pliny the Elder(23-79 AD) in ancient Rome wrote about 70 books, a significant part of which, to one degree or another, revealed the beginning of the history of the Earth.

Abu Ali Hussein ibn Abdullah ibn Sina Abu, or Avicenna(980-1037) in his encyclopedic work Kitab al-Shifa (book of healing the soul), he outlined very advanced medieval views. In his opinion, mountains and valleys occurred both as a result of the action of the internal forces of the earth, in particular strong earthquakes, and under the influence of external causes, water and wind. He believed that the world is eternal.

In the 15th century, the works of the Italian artist and scientist became widely known Leonardo Davinci(1452-1519). He believed that the outline of the land and oceans began to change in the distant past, that this process occurs slowly, this process is constant, and is the prototype of the biblical legend of the Flood; he argued that the Earth has existed much longer than stated in the Holy Scriptures.

The term geology itself was introduced by a Norwegian scientist Esholt M.P. in 1657

An independent branch of natural geology emerged in the 18th century. - early 19th century. This is related to the activities: William Smith, Abraham Gottlob Werner, James Hutton, Charles Lyell or Lyell,Mikhail Vasilievich Lomonosov, Vasily Mikhailovich Severgin.

William Smith(1769-1839), an English engineer, one of the founders of biostratigraphy, working through construction channels, established the age of sedimentary rocks based on the remains of fossil organisms contained in them. Compiled the first geological map of England with the distribution of rocks by age.

Biostratigraphy is a branch of stratigraphy that studies the distribution of fossil remains of organisms in sedimentary deposits in order to determine the relative age of these deposits.

Abraham Gottlob Werner(1749-1817) German geologist and mineralogist, founder of the German scientific school of mineralogy. Developed a classification of rocks and minerals. Founder of Neptunism.

Neptunism is a geological concept (by the 18th - early 19th centuries), based on ideas about the origin of all rocks from the waters of the world's oceans.

James Hutton(1726-1797) Scottish geologist presented the geological history of the Earth as destruction and emergence (of one continent into another). He pointed out the similarities between modern and ancient geological processes. Founder of plutonism.

Plutonism is a geological concept (by the 18th - early 19th centuries), about the leading role in the geological past internal forces Lands causing volcanism, earthquakes, tectonic movements.

Charles Lyell or Lyell(1797-1875) English naturalist, one of the founders of actualism and evolutionism in geology. In his main works entitled “Fundamentals of Geology as opposed to the Theory of Catastrophes,” he developed the doctrine of copper and continuous changes in the Earth’s surface under the influence of set geological factors.

Mikhail Vasilievich Lomonosov(1711-1765) the first scientific natural scientist of world importance. He discovered the atmosphere on Venus, described the structure of the Earth, explained the origin of many minerals and minerals, and published a manual on metallurgy. He considered all natural phenomena metallurgically.

Vasily Mikhailovich Severgin(1765-1826) Russian mineralogist and chemist. One of the founders of the Russian mineralogical school. Author of extensive information on mineralogy. Introduced the concept of mineral paragenesis. The author of works on chemical technology, also developed Russian scientific terminology.

Vladimir Ivanovich Vernadsky(1863-1945) Russian naturalist, thinker and public figure. The founder of a whole complex of modern geosciences. Geochemistry, biogeochemistry, radiogeology, hydrogeology, etc. He made significant contributions to mineralogy and crystallography. He developed genetic mineralogy, established the relationship between the form of crystalline minerals, its chemical composition, genesis and conditions of formation. Formulated the main ideas and problems of geochemistry. Since 1907 he conducted geological research in radiogeology. 1916-1940 he formulated the main principles and problems of biogeochemistry, also created the doctrine of the biosphere and its evolution, he was. He schematically outlined the main trends in the evolution of the biosphere:

expansion of life on the surface of the Earth, strengthening of its transformative influence on the abiotic environment.

increase in the scale and intensity of biogenic migrations of atoms. Emergence of qualitative geochemical functions living matter, the conquest of new mineralogical and energy resources by life.

transition of the biosphere to the noosphere

The noosphere is a new evolutionary state of the biosphere, in which intelligent human activity becomes a decisive factor in its development.

A qualitative leap in the history of geology, namely its transformation into a complex of sciences (at the turn of the 19th-20th centuries). It is associated with the conduct of physical, chemical and mathematical research methods.

The current stage of development of geology is associated with the introduction of information research methods in geology (geological databases, complex modeling), as well as with the emergence of modern technical means that allow a deeper and broader understanding of the object of geology and geological processes (computers, aerospace equipment, geophysical installations).

Structure of the Solar System.

The solar system includes: star; The sun, which is a yellow dwarf, 2 or 3 generations; planets, in order of distance from the sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. The planets are divided into 2 groups: 1. Terrestrial group, 2. External group (giant planets).

Characteristics of the terrestrial planets.

They are located closer to the Sun, have small sizes, high density, relatively small mass, have several satellites or do not have them at all. If they have an atmosphere that consists of heavy gases: carbon monoxide, nitrogen, ozone, krypton, oxygen, etc., their atmosphere is of endogenous origin, that is, atmospheric gases appeared from the bowels of the planets in the process of their evolution. These planets are mainly solid matter, the mass is silicon oxide and various metals, the outer shells (crust) are mainly represented by silicates, the innermost shells are alloys of heavy metals iron and nickel.

Characteristics of the giant planets

Large size and mass, relatively low density, located further from the Sun. All of them have a large number of satellites and have rings consisting of dust particles, ice crystals and large rock fragments. The composition of gas giant planets mainly includes light gases,

Hypotheses of the origin of the Solar System and their classification.

The first theory of the formation of the solar system, proposed in 1644 by Descartes. According to Descartes, the solar system was formed from a primary nebula, which had the shape of a disk and consisted of gas and dust (monistic theory). In 1745, Buffon proposed a dualistic theory; According to his version, the substance from which the planets are formed was torn away from the Sun by some large comet or other star passing too closely. If Buffon were right, then the appearance of a planet like ours would be an extremely rare event. Kant proceeded from the evolutionary development of a cold dust nebula, during which a central massive body first arose - the future Sun, and then planets, while Laplace considered the original nebula to be gaseous and very hot with a high rotation rate. Compressing under the influence of universal gravity, the nebula, due to the law of conservation of angular momentum, rotated faster and faster. Due to high centrifugal forces, the rings were successively separated from it. Then they condensed to form planets. Thus, according to Laplace's hypothesis, the planets formed before the Sun. However, despite the differences, a common important feature is the idea that the solar system arose as a result of the natural development of the nebula. That is why it is customary to call this concept the “Kant-Laplace hypothesis”. The most famous theory was put forward by Sir James Jeans, a famous popularizer of astronomy in the years between the First and Second World Wars. It is completely opposite to the Kant-Laplace hypothesis. If the latter depicts the formation of planetary systems as the only natural process of evolution from simple to complex, then in Jeans' hypothesis the formation of such systems is a matter of chance. The initial matter from which the planets were later formed was ejected from the Sun (which by that time was already quite “old” and similar to the present one) when a certain star accidentally passed near it. This passage was so close that it could almost be considered a collision. Thanks to tidal forces from a star colliding with the Sun, a stream of gas was ejected from the surface layers of the Sun. This jet will remain in the sphere of gravity of the Sun even after the star leaves the Sun. Then the jet will condense and give rise to planets. If Jeans's hypothesis were correct, the number of planetary systems formed during the ten billion years of its evolution could be counted on one hand. But there are actually many planetary systems, therefore, this hypothesis is untenable. And it does not follow from anywhere that a stream of hot gas ejected from the Sun can condense into planets. Thus, Jeans' cosmological hypothesis turned out to be untenable. The hypothesis is based on O.Yu. Schmidt is the idea of ​​the formation of planets by combining solid bodies and dust particles. The gas and dust cloud that arose near the Sun initially consisted of 98% hydrogen and helium. The remaining elements condensed into dust particles. The random movement of gas in the cloud quickly stopped: it was replaced by a calm movement of the cloud around the Sun. Dust particles concentrated in the central plane, forming a layer of increased density. When the density of the layer reached a certain critical value, its own gravity began to “compete” with the gravity of the Sun. The dust layer turned out to be unstable and broke up into separate dust clumps. Colliding with each other, they formed many solid dense bodies. The largest of them acquired almost circular orbits and began to overtake other bodies in their growth, becoming potential embryos of future planets. As more massive bodies, the new formations absorbed the remaining matter of the gas and dust cloud. Eventually nine formed major planets, whose orbital movement remains stable for billions of years.

General characteristics of the Earth. Basic physical parameters of the planet.

Physical fields of the Earth.

A physical field is a form of matter that carries out certain interactions between macroscopic bodies or particles that make up the substance. They are represented by gravitational, magnetic, geometric and electric fields and are studied by the relevant branches of science. Page 59 in geoscience http://www.russika.ru/pavlov/glava4.pdf

General characteristics of geospheres.

To date, humanity has received a lot of data that has made it possible to establish with a high degree of reliability the characteristics of the main geospheres of the earth.

Earth's core– takes central region of our planet. This is the deepest geosphere. The average radius of the core is about 3500 km; it is located deeper than 2900 km. It consists of two parts - a large outer and a small inner core. The nature of the Earth's inner core from a depth of 5000 km remains a mystery. This is a ball with a diameter of 2200 km, which scientists believe consists of iron and nickel and has a melting point of about 4500 ° C. The outer core is a liquid - molten iron mixed with nickel and sulfur. The pressure in this layer is less. The outer core is a spherical layer 2200 km thick.

Mantle- the most powerful shell of the Earth, occupying 2/3 of its mass and most of its volume. It also exists in the form of two spherical layers - the lower and upper mantle. The thickness of the lower part of the mantle is 2000 km, the upper part is 900 km. Due to the high pressure, the mantle material is most likely in a crystalline state. The temperature of the mantle is about 2500 ° C. It was the high pressures that determined this state of aggregation of the substance; otherwise, this temperature would lead to its melting. The asthenosphere, the lower part of the upper mantle, is in a molten state. This is the underlying layer of the upper mantle and lithosphere. In general, the upper mantle has an interesting feature: in relation to short-term loads it behaves like a rigid material, and in relation to long-term loads it behaves like a plastic one.

Lithosphere- This is the earth's crust, part of the underlying mantle, which forms a layer about 100 km thick. The earth's crust has a high degree of rigidity, but also great fragility. In the upper part it is composed of granites, in the lower part - basalts. The geological features of the crust are determined by the combined effects of the atmosphere, hydrosphere and biosphere on it - the three outermost shells of the planet. The composition of the bark and outer shells is continuously renewed. On the surface of the lithosphere, as a result of the combined activity of a number of factors, soil appears - this is a highly complex system that strives for equilibrium interaction with the environment.

Hydrosphere– the water shell of the Earth is represented on our planet by the World Ocean, fresh waters of rivers and lakes, glacial and groundwater. The total water reserves on Earth are 1.5 billion km 3 . Of this amount, 97% is salty sea water, 2% is frozen glacial water and 1% is fresh water. The hydrosphere is the continuous shell of the Earth, since the seas and oceans turn into underground water on land, and between the land and the sea there is a constant water cycle, the annual volume of which is 100 thousand km 3. Water is characterized by high heat capacity, heat of fusion and evaporation. Water is a good solvent, so it contains many chemical elements and compounds necessary to support life. Most of the Earth's surface is occupied by the World Ocean (71% of the planet's surface). It surrounds continents (Eurasia, Africa, North and South America, Australia and Antarctica) and islands. The ocean is divided by continents into four parts: the Pacific (50% of the area of ​​the World Ocean), Atlantic (25%), Indian (21%) and Arctic (4%) oceans. An important part of the Earth's hydrosphere are rivers - water streams flowing in natural channels and fed by surface and underground runoff from their basins.

Lakes, swamps, groundwater also part of the Earth's hydrosphere.

Glaciers, which form the icy shell of the Earth (cryosphere), are also part of the hydrosphere of our planet. They occupy 1/10 of the Earth's surface. They contain the main reserves fresh water (3/4).

Atmosphere- This is the air shell of the Earth that surrounds it and rotates with it. It consists of air - a mixture of gases (nitrogen, oxygen, inert gases, hydrogen, carbon dioxide, water vapor). In addition, the air contains a large amount of dust and various impurities generated by geochemical and biological processes on the surface of the planet.

The Earth's atmosphere has a layered structure, and the layers differ in physical and chemical properties. The most important of them are temperature and pressure, the change in which underlies the separation of atmospheric layers. Thus, the Earth's atmosphere is divided into: troposphere, stratosphere, ionosphere, mesosphere, thermosphere and exosphere.

Troposphere- This is the lower layer of the atmosphere that determines the weather on our planet. Has a constant temperature. Its thickness is 10–18 km. Pressure and temperature decrease with altitude. The troposphere contains the bulk of water vapor, clouds form and all types of precipitation form.

Thickness stratosphere reaches up to 50 km. There is an increase in temperature due to the absorption of solar radiation by ozone.

Ionosphere- this part of the atmosphere, starting from a height of 50 km and consisting of ions (electrically charged air particles). Air ionization occurs under the influence of the Sun.

Starts from an altitude of 80 km mesosphere, whose role is to absorb ultraviolet radiation from the Sun by ozone, water vapor and carbon dioxide.

At an altitude of 90–400 km there is thermosphere. The main processes of absorption and transformation of solar ultraviolet and x-ray radiation take place in it.

Geology is the study of the Earth and the sciences are interconnected. Geophysics studies the mantle, crust, outer liquid and inner solid core. The discipline examines oceans, surface and underground waters. This science also studies the physics of the atmosphere. In particular, aeronomy, climatology, meteorology. What is geology? Within the framework of this discipline, somewhat different research is carried out. Next, let's find out what geology studies.

General information

General geology is a discipline within which the structure and patterns of development of the Earth, as well as other planets belonging to the Solar System, are studied. Moreover, this also applies to their natural satellites. General geology is a complex of sciences. The research is carried out using physical methods.

Main directions

There are three of them: historical, dynamic and descriptive geology. Each direction differs in its basic principles, as well as research methods. Let's look at them in more detail next.

Descriptive direction

It studies the placement and composition of the corresponding bodies. In particular, this applies to their shapes, sizes, relationships and sequence of occurrence. In addition, this area deals with the description of rocks and various minerals.

Study of process evolution

This is what the dynamic direction does. In particular, the processes of destruction of rocks, their movement by wind, underground or ground waves, and glaciers are studied. This science also examines internal volcanic eruptions, earthquakes, movement of the earth's crust and accumulation of sediments.

Chronological order

Speaking about what geology studies, it should be said that research extends not only to phenomena that take place on Earth. One area of ​​the discipline analyzes and describes the chronological order of processes on Earth. These studies are carried out within the framework of historical geology. Chronological order organized in a special table. She is better known as She, in turn, is divided into four intervals. This was done in accordance with stratigraphic analysis. The first interval covers the following period: the formation of the Earth - the present time. Subsequent scales reflect the last segments of the previous ones. They are marked with stars on an enlarged scale.

Features of absolute and relative age

The study of the geology of the Earth is of utmost importance for humanity. Thanks to research, he became known, for example. Geological events are assigned an exact date that refers to a specific point in time. In this case we are talking about absolute age. Also, events can be assigned to certain intervals of the scale. This is relative age. Speaking about what geology is, it should be said that, first of all, it is a whole complex of scientific research. Within the discipline, various methods are used to determine the periods to which specific events are tied.

Radioisotope dating method

It was opened at the beginning of the 20th century. This method provides the ability to determine absolute age. Before its discovery, geologists were greatly limited. In particular, only relative dating methods were used in order to determine the age of the relevant events. Such a system is only able to establish the sequential order of the latest changes, and not the date of their occurrence. However, this method is still very effective. This applies to the case where materials devoid of radioactive isotopes are available.

Comprehensive research

The comparison of a certain stratigraphic unit with another occurs through strata. They are composed of sedimentary rocks, rocks, fossils and surface deposits. In most cases, relative age is determined using the paleontological method. At the same time, it is mainly based on the chemical and physical properties of rocks. As a rule, this age is determined by radioisotope dating. This refers to the accumulation of decay products of the corresponding elements that make up the material. Based on the data obtained, the approximate date of occurrence of each event is established. They are located at certain points on the general geological scale. To build an accurate sequence, this factor is very important.

Main sections

It is quite difficult to briefly answer the question of what geology is. It should be noted here that science includes not only the above areas, but also various groups of disciplines. At the same time, the development of geology continues today: new branches of the scientific system are emerging. Previously existing and emerging new groups of disciplines are associated with all three areas of science. Thus, there are no exact boundaries between them. What geology studies is also studied to varying degrees by other sciences. As a result, the system comes into contact with other areas of knowledge. There is a classification of the following groups of sciences:

Mineralogy

What does geology study in this section? Research concerns minerals, issues of their genesis, as well as classification. Lithology deals with the study of rocks that were formed in processes associated with the hydrosphere, biosphere and atmosphere of the Earth. It is worth noting that they are still inaccurately called sedimentary. Geocryology deals with the study of a number of characteristic features and properties acquired by permafrost rocks. Crystallography was originally one of the areas of mineralogy. Nowadays it can rather be classified as a physical discipline.

Petrography

This branch of geology studies metamorphic and igneous rocks mainly from a descriptive perspective. In this case we are talking about their genesis, composition, textural features and classification.

The earliest section of geotectonics

There is a direction that studies disturbances in the earth’s crust and the occurrence patterns of the corresponding bodies. Its name is structural geology. It must be said that geotectonics appeared as a science at the beginning of the 19th century. Structural geology studied medium- and small-scale tectonic dislocations. Size - tens to hundreds of kilometers. This science was finally formed only towards the end of the century. Thus, there was a transition to the identification of tectonic units on a global and continental scale. Subsequently, the teaching gradually developed into geotectonics.

Tectonics

This section of geology studies. It also includes the following areas:

1. Experimental tectonics.
2. Neotectonics.
3. Geotectonics.

Narrow Sections

• Volcanology. A rather narrow section of geology. He studies volcanism.
• Seismology. This branch of geology deals with the study of geological processes that occur during earthquakes. This also includes seismic zoning.
• Geocryology. This branch of geology focuses on the study of permafrost.
• Petrology. This section of geology studies the genesis, as well as the conditions of origin of metamorphic and igneous rocks.

Sequence of processes

Everything that geology studies contributes to a better understanding of certain processes on earth. For example, the chronology of events is a critical subject. After all, every geological science is historical in nature to one degree or another. They consider existing formations from this point of view. First of all, these sciences clarify the sequence of formation of modern structures.

Classification of periods

The entire history of the Earth is divided into two major stages, which are called eons. Classification occurs according to the appearance of organisms with hard parts that leave traces in sedimentary rocks. According to paleontology, they allow us to determine the relative geological age.

Subjects of research

The Phanerozoic began with the appearance of fossils on the planet. Thus, it developed open life. This period was preceded by the Precambrian and Cryptozoic. There was a hidden life at this time. Precambrian geology is considered a special discipline. The fact is that she studies specific, mostly repeatedly and strongly metamorphotic complexes. In addition, it is characterized by special research methods. Paleontology focuses on the study of ancient life forms. She describes fossil remains and traces of the vital activity of organisms. Stratigraphy determines the relative geological age of sedimentary rocks and the division of their strata. She also deals with the correlation of various formations. Paleontological definitions provide a source of data for stratigraphy.

What is applied geology

Some areas of science interact with others in one way or another. However, there are disciplines that are on the border with other branches. For example, mineral geology. This discipline deals with methods of prospecting and exploration of rocks. It is divided into the following types: geology of coal, gas, oil. Metallogeny also exists. Hydrogeology focuses on the study of groundwater. There are quite a lot of disciplines. They all have practical significance. For example, what is This section dealing with the study of the interaction of structures and environment. Soil geology is closely related to it, since, for example, the choice of material for the construction of buildings depends on the composition of the soil.

Other subtypes

• Geochemistry. This branch of geology focuses on the study of the physical properties of the Earth. This also includes a set of exploration methods, including electrical prospecting of various modifications, magnetic, seismic and gravity prospecting.
• Geobarothermometry. This science studies a set of methods for determining the temperatures and pressures of formation of rocks and minerals.
• Microstructural geology. This section deals with the study of rock deformation at the micro level. This refers to the scale of mineral aggregates and grains.
• Geodynamics. This science focuses on the study of processes on a planetary scale that occur as a result of the evolution of the planet. The connection between mechanisms in the earth's crust, mantle and core is studied.
• Geochronology. This section deals with determining the age of minerals and rocks.
• Lithology. It is also called petrography of sedimentary rocks. Engaged in the study of relevant materials.
• History of Geology. This section focuses on the totality of the information obtained and the mining business.
• Agrogeology. This section is responsible for the search, extraction and use of agricultural ores for agricultural purposes. In addition, he studies the mineralogical composition of soils.

The following geological sections focus on the study of the Solar System:

1. Cosmology
2. Planetology.
3. Space geology.
4. Cosmochemistry.

Mining geology

It is differentiated by types of mineral raw materials. There is a division into the geology of nonmetallic and ore minerals. This section studies the patterns of location of the corresponding deposits. Their connection with the following processes: metamorphism, magmatism, tectonics, sedimentation. Thus, an independent branch of knowledge appeared, which is called metallogeny. The geology of non-metallic minerals is also subdivided into the sciences of combustible substances and caustobioliths. This includes shale, coal, gas, oil. The geology of non-combustible rocks includes building materials, salts and more. This section also includes hydrogeology. It is dedicated to underground waters.

Economic direction

It is a rather specific discipline. It appeared at the intersection of economics and mineral geology. This discipline is focused on cost assessments of subsoil areas and deposits. The term "mineral resource", taking this into account, can be attributed to the economic sphere rather than to the geological one.

Intelligence Features

The geology of the deposit is an extensive scientific complex, within the framework of which activities are carried out to determine the industrial significance of rock areas that have received a positive assessment based on the results of prospecting and assessment activities. During exploration, geological and industrial parameters are set. They, in turn, are necessary for the appropriate assessment of sites. This also applies to the processing of extracted minerals, the provision of operational activities, and the design of construction of mining enterprises. Thus, the morphology of the bodies of the corresponding materials is determined. This is very important when selecting a mineral post-processing system. The contours of their bodies are being established. In this case, geological boundaries are taken into account. In particular, this applies to fault surfaces and contacts of lithologically different rocks. The nature of the distribution of minerals, the presence of harmful impurities, and the content of associated and main components are also taken into account.

Upper crustal horizons

They are studied by engineering geology. The information obtained during the study of soils makes it possible to determine the suitability of the relevant materials for the construction of specific objects. The upper layers of the earth's crust are often called the geological environment. The subject of this section is information about its regional features, dynamics and morphology. Interaction with engineering structures. The latter are often called elements of the technosphere. This takes into account the planned, current or completed economic activity of a person. Engineering-geological assessment of the territory involves the identification of a special element, which is characterized by homogeneous properties.

A Few Basic Principles

The above information allows you to understand quite clearly what geology is. It must be said that science is considered historical. It has many important tasks. First of all, this concerns the determination of the sequence of geological events. To efficiently perform these tasks, a number of intuitively consistent and simple features related to the temporal relationship of rocks have long been developed. Intrusive relationships represent contacts between the corresponding rocks and their strata. All conclusions are made based on the detected signs. Relative age also allows us to determine current relationships. For example, if it breaks rocks, then this allows us to conclude that the fault was formed later than them. The principle of continuity is that the building material from which the layers are formed can be stretched across the surface of the planet if it is not limited by some other mass.

Historical information

The first observations are usually attributed to dynamic geology. In this case, we mean information about movement coastlines, erosion of mountains, volcanic eruptions and earthquakes. Attempts to classify geological bodies and describe minerals were made by Avicenna and Al-Burini. Some scholars now suggest that modern geology originated in the medieval Islamic world. Similar research was carried out during the Renaissance by Girolamo Fracastoro and Leonardo da Vinci. They were the first to suggest that fossil shells are the remains of extinct organisms. They also believed that the history of the Earth itself was much longer than the biblical ideas about it. IN late XVII century, a general theory about the planet arose, which became known as diluvianism. Scientists of the time believed that the fossils and sedimentary rocks themselves were formed due to a global flood.

The need for minerals increased very quickly towards the end of the 18th century. Thus, the subsoil began to be studied. Basically, the accumulation of factual materials, descriptions of the properties and characteristics of rocks, as well as studies of the conditions of their occurrence were carried out. In addition, observation techniques were developed. For almost the entire 19th century, geology was entirely concerned with the question of the exact age of the Earth. Estimates have varied quite widely, from a hundred thousand years to billions. However, the age of the planet was initially determined at the beginning of the 20th century. Radiometric dating contributed greatly to this. The estimate obtained then was about 2 billion years. Currently, the true age of the Earth has been established. It is approximately 4.5 billion years old.

Instructions

The origins of geology date back to ancient times and are associated with the very first information about rocks, ores and minerals. The term “geology” was introduced by the Norwegian scientist M.P. Esholt in 1657, and it became an independent branch of natural science at the end of the 18th century. The turn of the 19th-20th centuries was marked by a qualitative leap in the development of geology - its transformation into a complex of sciences in connection with the introduction of physicochemical and mathematical research methods.

Modern geology includes many of its constituent disciplines, revealing the secrets of the Earth in different areas. Volcanology, crystallography, mineralogy, tectonics, petrography - this is not a complete list of independent branches of geological science. Geology is also closely related to areas of applied importance: geophysics, tectonophysics, geochemistry, etc.

Geology is often called the science of “dead” nature, in contrast to. Of course, the changes occurring in the Earth’s shell are not so obvious and take centuries and millennia. It is geology that tells us how our planet was formed and what processes took place on it over the many years of its existence. The science of geology tells in detail about the modern face of the Earth, created by geological “actors” - wind, cold, earthquakes, volcanic eruptions.

The practical importance of geology for human society cannot be overestimated. She studies the bowels of the earth, allowing us to extract from them, without which human existence would be impossible. Humanity has come a long way in evolution - from the “stone” period to the century high technology. And each of his steps was accompanied by new discoveries in the field of geology, which brought tangible benefits for the development of society.

Geology can also be called historical science, because with its help you can monitor changes in the composition of minerals. By studying the remains of living creatures that inhabited the planet thousands of years ago, geology provides answers to questions about when these species inhabited the Earth and why they became extinct. From fossils one can judge the sequence of events that took place on the planet. Way of development organic life over millions of years, imprinted in the layers of the Earth, which are studied by the science of geology.

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note

What is geology. Geology (from geology) is a complex of sciences about the earth's crust and deeper spheres of the Earth; in the narrow sense of the word - the science of the composition, structure, movements and history of the development of the earth's crust and the placement of minerals in it.

Helpful advice

This article will discuss what geology is. The question is revealed about what this science is about, what it studies and what its goals and objectives are. We will cover the basics and methods of geology. Absolutely each of these areas has its own methods, as well as principles of research. Historical geology studies the sequence of geological processes that occurred in the past.

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• what is geology

In the minds of most people, a geologist is a bearded man with a hammer and a backpack, who is engaged exclusively in searching for minerals in complete absence of connection with civilization. In fact, geology is a very complex and multifaceted science.

What do geologists do?

Geology of the composition of the earth's crust, its structure, as well as the history of its formation. There are three main directions of geology: dynamic, historical and descriptive. Dynamic studies changes in the earth's crust as a result of various processes, such as erosion, destruction, earthquakes, and volcanic activity. Historical geologists focus on imagining the processes and changes that occurred on the planet in the past. Most of all, specialists in descriptive geology correspond to the usual image of a geologist, since it is this branch of science that studies the composition of the earth’s crust and the content of certain fossils or rocks in it.

Geology became a popular science in the era of the scientific and technological revolution, when humanity needed many new resources and energy.

Subsoil studies for descriptive geology include not only expeditions to collect samples or exploratory drilling, but also data analysis, compilation of geological maps, assessment of development prospects, and construction of computer models. Work “in the field,” that is, direct research on the ground, takes only a few months of the season, and the geologist spends the rest of the time. Naturally, the main object of the search is minerals.

It is geology that deals, in particular, with finding out the exact age of planet Earth. Thanks to the development of scientific methods, it is known that the planet is about 4.5 billion years old.

Problems of applied geology

Mineral geoscientists are traditionally divided into two main groups: those who look for ore deposits and those who look for non-metallic minerals. This division is due to the fact that the principles and patterns of formation for non-metallic minerals are different, therefore geologists, as a rule, specialize in one thing. Useful ores include most metals, such as iron, nickel, gold, and some types of minerals. Non-metallic minerals include combustible materials (oil, gas, stone), various building materials (clay, marble, crushed stone), chemical ingredients and, finally, precious and semiprecious stones, such as diamonds, rubies, emeralds, jasper, carnelian and many others.

The job of a geologist is to predict, based on analytical data, the occurrence of minerals in a particular area, conduct research on an expedition in order to confirm or refute his assumptions, and then, based on the information received, make a conclusion about the prospects for industrial development of the deposit. In this case, the geologist proceeds from the estimated number of minerals, their percentage in the earth’s crust, and the commercial feasibility of extraction. Therefore, a geologist must not only be physically resilient, but also have the ability for analytical thinking, know the basics of economics and geodesy, and constantly improve their knowledge and skills.

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Geoecology is a scientific field covering the fields of ecology and geography. The subject and objectives of this science are not precisely defined; within its framework, many different problems related to the interaction of nature and society, human influence on landscapes and others are studied. geographical shells.

History of geoecology

Geoecology became a separate science about a hundred years ago, when the German geographer Karl Troll described the field of study of landscape ecology. From his point of view, this should integrate ecological principles in the study of ecosystems.

Geoecology developed slowly; in the Soviet Union, this term was first coined in the 70s. By the beginning of the 21st century, both adjacent fields - and - became accurate enough to predict how the nature and various shells of the Earth will change depending on human influence. Moreover, scientists can already find ways to solve problems associated with the negative impact of man-made activities on nature. Therefore, geoecology began to develop rapidly in the new millennium, and the scope of its activities expanded.

Geoecology

Despite the fact that this is becoming increasingly popular, from a scientific point of view it is not sufficiently described. Researchers more or less agree on the tasks of geoecology, but they do not give a clear subject of research for this science. One of the most common assumptions about the subject sounds like this: these are processes occurring in the environment and in various shells of the Earth - the hydrosphere, atmosphere and others, which arise as a result of anthropogenic intervention and entail certain consequences.

There is a very important factor in the study of geoecology - it is necessary to take into account both spatial and temporal relationships in research. In other words, for geoecologists, both the human influence on nature in different geographical conditions and changes in these consequences over time are important.

Geoecologists study sources that affect the biosphere, study their intensity and identify the spatial and temporal distribution of their effects. They create special information systems with which they can ensure constant control over natural environment. Along with environmentalists, they consider pollution levels in various areas: in the World Ocean, in the lithosphere, in internal waters. They try to detect human influence on the formation of ecosystems and their functioning.

Geoecology deals not only with the current situation, but also forecasts and models possible consequences ongoing processes. This allows you to prevent unwanted changes rather than deal with their consequences.

“Geology is a way of life,” a geologist will most likely say when answering a question about his profession, before moving on to dry and boring formulations, explaining that geology is about the structure and composition of the earth, the history of its birth, formation and patterns development, about the once countless, but today, alas, “estimated” riches of its depths. Other planets of the solar system are also objects of geological research.

The description of a particular science often begins with the history of its origin and formation, forgetting that the narrative is full of incomprehensible terms and definitions, so it’s better to get to the point first.

Stages of geological research

The most general scheme sequence of research into which all geological work aimed at identifying mineral deposits can be “squeezed” (hereinafter referred to as MPO), essentially looks like this: geological survey (mapping outcrops of rocks and geological formations), prospecting work, exploration, reserves calculation, geological report. Surveying, searching and reconnaissance, in turn, are naturally divided into stages depending on the scale of the work and taking into account their expediency.

To carry out such a complex of work, an entire army of specialists from a wide range of geological specialties is involved, which a real geologist must master much more than at the “a little bit of everything” level, because he is faced with the task of summarizing all this diverse information and ultimately arriving at the discovery of a deposit ( or make it), since geology is a science that studies the bowels of the earth primarily for the development of mineral resources.

Family of geological sciences

Like other natural sciences (physics, biology, chemistry, geography, etc.), geology is a whole complex of interrelated and intertwined scientific disciplines.

Directly geological subjects include general and regional geology, mineralogy, tectonics, geomorphology, geochemistry, lithology, paleontology, petrology, petrography, gemology, stratigraphy, historical geology, crystallography, hydrogeology, marine geology, volcanology and sedimentology.

Applied, methodological, technical, economic and other sciences related to geology include engineering geology, seismology, petrophysics, glaciology, geography, mineral geology, geophysics, soil science, geodesy, oceanography, oceanology, geostatistics, geotechnology, geoinformatics, geotechnology, cadastre and monitoring lands, land management, climatology, cartography, meteorology and a number of atmospheric sciences.

“Pure” field geology still remains largely descriptive, which imposes a certain moral and ethical responsibility on the performer, therefore geology, having developed its own language, like other sciences, cannot do without philology, logic and ethics.

Since prospecting and exploration routes, especially in hard-to-reach areas, are practically uncontrolled work, a geologist is always susceptible to the temptation of subjective, but competently and beautifully presented judgments or conclusions, and this, unfortunately, happens. Harmless “inaccuracies” can lead to very serious consequences both in scientific-production and material-economic terms, so a geologist simply does not have the right to deception, distortion and error, like a sapper or a surgeon.

The backbone of the geosciences is arranged in a hierarchical series (geochemistry, mineralogy, crystallography, petrology, lithology, paleontology and geology itself, including tectonics, stratigraphy and historical geology), reflecting the subordination of successively more complex objects of study from atoms and molecules to the Earth as a whole.

Each of these sciences branches widely in various directions, just as geology itself includes tectonics, stratigraphy and historical geology.

Geochemistry

The field of view of this science lies in the problems of the distribution of elements in the atmosphere, hydrosphere and lithosphere.

Modern geochemistry is a complex of scientific disciplines, including regional geochemistry, biogeochemistry and geochemical methods for searching for mineral deposits. The subject of study for all these disciplines is the laws of migration of elements, the conditions of their concentration, separation and redeposition, as well as the processes of evolution of the forms of occurrence of each element or associations of several, especially similar in properties.

Geochemistry is based on the properties and structure of the atom and crystalline matter, on data on thermodynamic parameters characterizing part of the earth's crust or individual shells, as well as on general patterns formed by thermodynamic processes.

The direct task of geochemical research in geology is the detection of mineral deposits, therefore, ore mineral deposits are necessarily preceded and accompanied by geochemical survey, based on the results of which the areas of dispersion of the useful component are identified.

Mineralogy

One of the main and oldest branches of geological science, studying the huge, beautiful, unusually interesting and mysterious world of minerals. Mineralogical studies, the goals, objectives and methods of which depend on specific tasks, are carried out at all stages of prospecting and geological exploration and include a wide range of methods from visual assessment mineral composition to electron microscopy and X-ray diffraction diagnostics.

At the stages of surveying, prospecting and exploration of mineral deposits, research is carried out to clarify mineralogical prospecting criteria and a preliminary assessment of the practical significance of potential deposits.

During the exploration stage of geological work and when assessing reserves of ore or non-metallic raw materials, its full quantitative and qualitative mineral composition is established with the identification of useful and harmful impurities, data on which are taken into account when choosing a processing technology or making a conclusion about the quality of raw materials.

In addition to a comprehensive study of the composition of rocks, the main tasks of mineralogy are the study of the patterns of combination of minerals in natural associations and the improvement of the principles of taxonomy of mineral species.

Crystallography

Crystallography was once considered a part of mineralogy, and the close connection between them is natural and obvious, but today it is an independent science with its own subject and its own research methods. The objectives of crystallography are to comprehensively study the structure, physical and optical properties of crystals, the processes of their formation and the characteristics of interaction with the environment, as well as changes occurring under the influence of influences of various natures.

The science of crystals is divided into physicochemical crystallography, which studies the patterns of formation and growth of crystals, their behavior in various conditions depending on the shape and structure, and geometric crystallography, the subject of which is the geometric laws governing the shape and symmetry of crystals.

Tectonics

Tectonics is one of the core branches of geology, which studies in structural terms, the features of its formation and development against the background of different-scale movements, deformations, faults and dislocations caused by deep processes.

Tectonics is divided into regional, structural (morphological), historical and applied branches.

The regional direction operates with such structures as platforms, plates, shields, folded areas, depressions of seas and oceans, transform faults, rift zones, etc.

As an example, we can cite the regional structural-tectonic plan that characterizes the geology of Russia. The European part of the country is located on the East European Platform, composed of Precambrian igneous and metamorphic rocks. The territory between the Urals and the Yenisei is located on the West Siberian Platform. The Siberian Platform (Central Siberian Plateau) extends from the Yenisei to the Lena. Folded areas are represented by the Ural-Mongolian, Pacific and partially Mediterranean fold belts.

Morphological tectonics, compared to regional tectonics, studies structures of a lower order.

Historical geotectonics deals with the history of the origin and formation of the main types of structural forms of oceans and continents.

The applied direction of tectonics is associated with identifying patterns of placement various types MPO in connection with certain types of morphostructures and features of their development.

In the “mercantile” geological sense, faults in the earth’s crust are considered as ore supply channels and ore-controlling factors.

Paleontology

Literally meaning “the science of ancient beings,” paleontology studies fossil organisms, their remains and traces of life, mainly for the stratigraphic division of rocks in the earth's crust. The competence of paleontology includes the task of restoring a picture reflecting the process of biological evolution based on data obtained as a result of reconstruction of the appearance, biological features, methods of reproduction and nutrition of ancient organisms.

According to quite obvious signs, paleontology is divided into paleozoology and paleobotany.

Organisms are sensitive to changes in the physical and chemical parameters of their environment, so they are reliable indicators of the conditions in which rocks were formed. Hence the close connection between geology and paleontology.

Based on paleontological research, together with the results of determining the absolute age of geological formations, a geochronological scale has been compiled, in which the history of the Earth is divided into geological eras(Archaean, Proterozoic, Paleozoic, Mesozoic and Cenozoic). Eras are divided into periods, and those, in turn, are divided into epochs.

We live in the Pleistocene era (20 thousand years ago to the present) of the Quaternary period, which began about 1 million years ago.

Petrography

Petrography (petrology) deals with the study of the mineral composition of igneous, metamorphic and sedimentary rocks, their textural and structural characteristics and genesis. Research is carried out using a polarizing microscope in rays of transmitted polarized light. To do this, thin (0.03-0.02 mm) plates (sections) are cut from rock samples, then glued to a glass plate with Canada balsam (the optical characteristics of this resin are close to the parameters of glass).

Minerals become transparent (most of them), and minerals and their constituent rocks are identified based on their optical properties. Interference patterns in thin sections resemble patterns in a kaleidoscope.

Petrography of sedimentary rocks occupies a special place in the cycle of geological sciences. Its great theoretical and practical significance is due to the fact that the subject of research is modern and ancient (fossil) sediments, which occupy about 70% of the Earth's surface.

Engineering Geology

Engineering geology is the science of those compositional features physical and chemical properties, formation, occurrence and dynamics of the upper horizons of the earth's crust, which are associated with economic, mainly engineering and construction activities of humans.

Engineering geological surveys are aimed at performing a comprehensive and comprehensive assessment of geological factors caused by economic activity human interaction with natural geological processes.

If we remember that, depending on the guiding method, natural sciences are divided into descriptive and exact, then engineering geology, of course, belongs to the latter, unlike many of its “comrades in the shop.”

Marine Geology

It would be unfair to ignore the vast branch of geology that studies geological structure and features of the development of the bottom of oceans and seas. If you follow the shortest and most succinct definition that characterizes geology (the study of the Earth), then marine geology is the science of the sea (ocean) bottom, covering all branches of the “geological tree” (tectonics, petrography, lithology, historical and Quaternary geology, paleogeography , stratigraphy, geomorphology, geochemistry, geophysics, the study of minerals, etc.).

Research in the seas and oceans is carried out from specially equipped vessels, floating drilling rigs and pontoons (on the shelf). For sampling, in addition to drilling, dredges, grab-type bottom grabs and straight-through tubes are used. Using autonomous and towed vehicles, discrete and continuous photographic, television, seismic, magnetometric and geolocation surveys are carried out.

In our time, many problems of modern science have not yet been solved, and these include the unsolved secrets of the ocean and its depths. Marine geology has been given the honor not only for the sake of science to “make the secret obvious”, but also to master the colossal mineral

The main theoretical task of the modern marine branch of geology remains the study of the history of the development of the oceanic crust and the identification of the main patterns of its geological structure.

Historical geology is the science of the patterns of development of the earth's crust and the planet as a whole in the historically foreseeable past from the moment of its formation to the present day. Studying the history of the formation of the structure of the lithosphere is important because the tectonic movements and deformations occurring in it seem the most important factors, causing most of the changes that occurred on Earth in past geological eras.

Now, having received general idea about geology, we can turn to its origins.

An excursion into the history of Earth science

It is difficult to say how far back the history of geology goes back thousands of years, but the Neanderthal already knew what to make a knife or ax out of, using flint or obsidian (volcanic glass).

From the time of primitive man until the middle of the 18th century, the pre-scientific stage of accumulation and formation of geological knowledge lasted, mainly about metal ores, building stones, salts and groundwater. They started talking about rocks, minerals and geological processes in the interpretation of that time already in ancient times.

TO XIII century In Asian countries, mining industries are developing and the foundations of mining knowledge are emerging.

During the Renaissance (XV-XVI centuries), the heliocentric idea of ​​the world was affirmed (G. Bruno, G. Galileo, N. Copernicus), the geological ideas of N. Stenon, Leonardo da Vinci and G. Bauer were born, and cosmogonic concepts were formulated. Descartes and G. Leibniz.

During the period of formation of geology as a science (XVIII-XIX centuries), the cosmogonic hypotheses of P. Laplace and I. Kant and the geological ideas of M. V. Lomonosov and J. Buffon appeared. Stratigraphy (I. Lehman, G. Füxel) and paleontology (J.B. Lamarck, W. Smith) are emerging, crystallography (R.J. Gayuy, M.V. Lomonosov), mineralogy (I.Ya. Berzelius, A. Kronstedt, V. M. Severgin, K. F. Moos, etc.), geological mapping begins.

During this period, the first geological societies and national geological services were created.

From the second half of the 19th to the beginning of the 20th century, the most significant events were the geological observations of Charles Darwin, the creation of the doctrine of platforms and geosynclines, the emergence of paleogeography, the development of instrumental petrography, genetic and theoretical mineralogy, the emergence of the concept of magma and the doctrine of ore deposits. Petroleum geology began to emerge and geophysics (magnetometry, gravimetry, seismometry, and seismology) began to gain momentum. In 1882, the Geological Committee of Russia was founded.

The modern period of development of geology began in the middle of the 20th century, when Earth science adopted computer technology and acquired new laboratory instruments, instruments and technical means that made it possible to begin the geological and geophysical study of the oceans and nearby planets.

The most outstanding scientific achievements were the theory of metasomatic zoning by D. S. Korzhinsky, the doctrine of metamorphic facies, M. Strakhov’s theory of the types of lithogenesis, the introduction of geochemical methods for searching for ore deposits, etc.

Under the leadership of A.L. Yanshin, N.S. Shatsky and A.A. Bogdanov, overview tectonic maps of the countries of Europe and Asia were created, and paleogeographic atlases were compiled.

The concept of a new global tectonics has been developed (J. T. Wilson, G. Hess, V. E. Khain, etc.), geodynamics, engineering geology and hydrogeology have stepped far forward, a new direction in geology has emerged - environmental, which has become a priority today.

Problems of modern geology

Today, on many fundamental issues, the problems of modern science still remain unresolved, and there are at least one hundred and fifty such questions. We are talking about the biological foundations of consciousness, the mysteries of memory, the nature of time and gravity, the origin of stars, black holes and the nature of other cosmic objects. Geology also faces many problems that still need to be dealt with. This concerns mainly the structure and composition of the Universe, as well as the processes occurring inside the Earth.

Nowadays, the importance of geology is increasing due to the need to control and take into account the growing threat of catastrophic geological consequences associated with irrational economic activities that aggravate environmental problems.

Geological education in Russia

The formation of modern geological education in Russia is associated with the opening of the Corps of Mining Engineers in St. Petersburg (the future Mining Institute) and the creation of Moscow University, and the heyday began when in 1930 in Leningrad it was created and then transferred to Geology (now GIN AH CCCP ).

Today, the Geological Institute occupies a leading position among research institutions in the fields of stratigraphy, lithology, tectonics and the history of sciences of the geological cycle. The main areas of activity are related to the development of complex fundamental problems of the structure and formation of the oceanic and continental crust, the study of the evolution of continental rock formation and sedimentation in the oceans, geochronology, global correlation of geological processes and phenomena, etc.

By the way, the predecessor of the GIN was the Mineralogical Museum, renamed in 1898 to the Museum of Geology, and then in 1912 to the Geological and Mineralogical Museum named after. Peter the Great.

Since its inception, the basis of geological education in Russia has been the principle of the trinity: science - education - practice. Despite the perestroika upheavals, educational geology still follows this principle today.

In 1999, by the decision of the boards of the Ministries of Education and natural resources Russia adopted the concept of geological education, which was tested in educational institutions and production teams that “grow” geological personnel.

Today, higher geological education can be obtained in more than 30 universities in Russia.

And even though going “on exploration in the taiga” or going “to the sultry steppes” in our time is no longer as prestigious a job as it once was, a geologist chooses it because “happy is he who knows the aching feeling of the road”...