Indo-Iranian languages

(Aryan languages) - a branch of the Indo-European family of languages ​​(see Indo-European languages), splitting into Indian (Indo-Aryan) languages ​​and Iranian languages; it also includes Dardic languages ​​and Nuristan languages. The total number of speakers is 850 million people. Indo-Iranian languages ​​are genetic concept, motivated by the presence of an Indo-Iranian linguistic community that preceded the split into separate groups and preserved a number of common archaisms dating back to the Indo-European era. It is very likely that the core of this community formed in the southern Russian steppes (as evidenced by archaeological finds in Ukraine, traces of linguistic contacts with the Finno-Ugric peoples, which most likely took place north of the Caspian Sea, Aryan traces in the toponymy and hydronymy of Tavria and the Northern Black Sea region etc.) and continued to develop during the period of coexistence in Central Asia or in surrounding areas.

Comparative historical grammar reconstructs for these languages ​​a common initial system of phonemes, a common vocabulary, common system morphology and word formation and even general syntactic features. Thus, in phonetics, Indo-Iranian languages ​​are characterized by the coincidence of Indo-European *ē̆, *ō̆, *ā̆ in Indo-Iranian ā̆, the reflection of Indo-European *ə in Indo-Iranian i, the transition of Indo-European *s after i, u, r, k into an š-shaped sound; in morphology, a basically identical system of name declension is developed and a number of specific verbal formations are formed, etc. The general lexical composition includes the names of key concepts of Indo-Iranian culture (primarily in the field of mythology), religion, social institutions, objects material culture, names, which confirms the presence of an Indo-Iranian community. The common name is *arya‑, which is reflected in many Iranian and Indian ethnic terms over a vast territory (the name of the modern state of Iran comes from the form of this word). The most ancient Indian and Iranian monuments “Rigveda” and “Avesta” in their most archaic parts are so close to each other that they can be considered as two versions of one source text. Further migrations of the Aryans led to the division of the Indo-Iranian branch of languages ​​into 2 groups, the separation of which began with the entry of the ancestors of modern Indo-Aryans into northwestern India. Linguistic traces from one of the earlier waves of migration have been preserved - Aryan words in the languages ​​of Asia Minor and Western Asia from 1500 BC. e. (names of gods, kings and nobles, horse breeding terminology), the so-called Mitanni Aryan (belonging to the Indian group, but not fully explained from the Vedic language).

The Indo-Aryan group turned out to be more conservative in many respects than the Iranian one. It better preserved some archaisms of the Indo-European and Indo-Iranian eras, while the Iranian group underwent a number of significant changes. In phonetics, these are changes primarily in the field of consonantism: spirantization of voiceless stops, loss of aspiration for consonants, transition from s to h. In morphology, it is a simplification of the complex ancient inflectional paradigm of noun and verb, primarily in the Old Persian language.

The ancient Indian languages ​​are represented by the Vedic language, Sanskrit, and also some words of Mitannian Aryan; Central Indian - Pali, Prakritami, Apabhransha; new Indo-Aryan languages ​​- Hindi, Urdu, Bengali, Marathi, Gujarati, Punjabi, Oriya, Assamese, Sindhi, Nepali, Sinhalese, Maldivian, Gypsy languages ​​and others.

Ancient Iranian languages ​​are represented by Avestan, Old Persian (the language of Achaemenid inscriptions), as well as in separate words in the Greek transmission in Scythian and Median (one can judge some phonetic features of these languages). The Central Iranian languages ​​include Middle Persian (Pahlavi), Parthian, Sogdian, Khorezmian, Saka languages ​​(dialects), Bactrian (primarily the language of the inscription in Surkhkotal). New Iranian languages ​​include Persian, Tajik, Pashto (Afghan), Ossetian, Kurdish, Baluchi, Gilan, Mazanderan, Tat, Talysh, Parachi, Ormuri, Yagnob, Munjan, Yidga, Pamir (Shughnan, Rushan, Bartang, Oroshor, Sarykol, Yazgulyam , Ishkashim, Wakhan) and others.

Modern Indo-Iranian languages ​​are widespread in India, Pakistan, Bangladesh, Nepal, Sri Lanka, the Maldives, Iran, Afghanistan, Iraq (northern regions), Turkey (eastern regions), the USSR (in Tajikistan, the Caucasus, etc.). They are characterized by a number of common trends, which indicates a common typology of development of these two groups of languages. The ancient inflection of name and verb has been almost completely lost. In the nominal paradigm, instead of a multi-case inflectional system of declension, a contrast is developed between direct and indirect forms, accompanied by function words: postpositions or prepositions (only in Iranian languages), i.e., an analytical way of expressing grammatical meaning. In a number of languages, on the basis of these analytical constructions, a new agglutinative case inflection is formed (the eastern type of Indian languages, among Iranian languages ​​- Ossetian, Baluchi, Gilan, Mazanderan). In the system of verb forms, complex analytical constructions that convey meanings of aspect and tense, analytical passive, and analytical word formation are becoming widespread. In a number of languages, new synthetic contractions are being formed. verb forms, in which function words of analytical constructions acquire the status of morphemes (in Indian languages, primarily in languages ​​of the eastern type, this process has gone further; in Iranian it is observed only in the colloquial speech of many living languages). In syntax, the new Indo-Iranian languages ​​are characterized by a tendency towards a fixed word order and, for many of them, towards ergativity in its various variants. The general phonological trend in modern languages of these two groups is the loss of the phonological status of quantitative vowel opposition, the increased importance of the rhythmic structure of the word (sequences of long and short syllables), the very weak nature of dynamic word stress and the special role of phrasal intonation.

The Dardic languages ​​constitute a special intermediate group of the Indo-Iranian language branch. Scientists have no consensus regarding their status. R. B. Shaw, S. Konov, J. A. Grierson (in early works) saw an Iranian basis in the Dardic languages, noting their special closeness to the Pamir languages. G. Morgenstierne generally classifies them as Indian languages, as does R. L. Turner. Grierson (in later works), D.I. Edelman consider them independent group, occupying an intermediate place between the Indo-Aryan and Iranian languages. According to many features, the Dardic languages ​​are included in the Central Asian linguistic union.

Edelman D.I., Comparative grammar of East Iranian languages. Phonology, M., 1986; see also the literature under the articles Indian (Indo-Aryan) languages, Iranian languages, Dardic languages, Nuristan languages.

T. Ya. Elizarenkova.

Materials devoted to the study of Indo-Iranian languages, in addition to general linguistic journals (see Linguistic journals), are published in specialized journals in a number of countries:

"Indische Bibliothek" (Bonn, 1820-30), "Indische Studien" (B. - Lpz., 1850-98), "Zeitschrift für Indologie und Iranistik" (Lpz., 1922-36), "Indo-Iranian Journal" (The Hague, 1957-), “Indological Studies: Journal of the Department of Sanskrit” (Delhi, 1972-), “Studia Iranica” (P., 1972-), “Studien zur Indologie und Iranistik” (Reinbek, Germany, 1975-).

In the south of the island), the Republic of Maldives ( Maldivian), Nepal ( Nepali); outside this region - Gypsy and parya ( dialect on the territory of the USSR in the Gissar Valley of Tajikistan). The total number of speakers is 770 million people. In the west and north-west I. (i.) I. border with Iranian Balochi , Pashto) and Dardic languages, in the north and northeast - with Tibetan and Himalayan, in the east - next to Tibeto-Burman And Mon-Khmer languages, in the south - from Dravidian (Telugu , Kannada). In India, in the massif I. (i.) i. interspersed with linguistic islands of other linguistic groups ( munda, Mon-Khmer, Dravidian and others).

The oldest period of development of I. (i.) i. presented Vedic language(the language of the cult, which supposedly functioned conditionally from the 12th century BC) and Sanskrit in several of it literary varieties (epic - 3-2 centuries BC, epigraphic - first centuries AD, classical Sanskrit - flourishing 4-5 centuries AD). Individual Indo-Aryan words belonging to a dialect different from Vedic (names of gods, kings, horse breeding terms) have been attested since the 15th century. BC e. in the so-called Mitannian Aryan in documents from Asia Minor and Western Asia.

For the ancient Indian state on phonetic -phonological level is characterized by the presence of classes of occlusive noisy aspirated and cerebral phonemes(preserved with some changes until current state), phonological contrast of simple vowels by longitude​/​shortness in syllables any type, acceptable consonant the outcome of the word along with the vowel, the presence of numerous combinations of consonants, especially complex ones, in the middle of the word. Based on ancient Indian morphology lies a system of quality alternations vowel in root and in the suffix. The language is characterized by a developed synthetic build. Grammatical meanings are conveyed by a combination of numerous types basics name and verb with one or another series of endings. The name has 8 cases , 3 numbers, verb - 3 faces, 3rd, 6-7 times , 4-6 inclinations , 3 collateral. Paradigm verb is represented by many dozens of personal inflectional forms. IN word formation Prefixation and suffixation are productive, and a number of suffixes require a certain level of alternation of the root vowel. The morphological structure of the word is extremely clear. IN syntax with predominant final position of the verb predicate and prepositivity definitions word order free.

Central Indian period of development of I. (i.) i. represented by numerous languages ​​and dialects, previously used orally, and then in writing by the middle of the 1st millennium BC. e. Of these, the most archaic Pali(the language of the Buddhist Canon), followed by prakrits(the Prakrits of the inscriptions are more archaic) and Apabkhransha (dialects that formed by the middle of the 1st millennium AD as a result of the development of Prakrits and are a transitional link to the New Indian languages). The Middle Indian state, in comparison with the Old Indian state, at the phonetic-phonological level is characterized by sharp restrictions on combinations of consonants, the absence of a consonantal outcome of the word, a change in intervocalic stops, the appearance nasalized vowel phonemes, strengthening rhythmic patterns in the word (vowels are contrasted in length/shortness only in open syllables). As a result of these phonetic changes, clarity is lost morphemic word structure, the system of qualitative morphonological vowel alternations and the distinctive power weakens inflections. Morphology shows tendencies towards unification of types declination, to the confusion of nominal and pronominal inclination towards a strong simplification of the case paradigm and the development of the system postpositional function words, to the disappearance of a whole series verb categories and narrowing the scope of use of personal forms (starting with Prakrits in the function of personal forms of the verb in past tense are used only participles). A number of additional restrictions appear in the syntax, leading to greater standardization of the structure proposals.

New Indian period in the development of I. (i.) i. begins after the 10th century. It is represented by approximately two dozen major languages ​​and a large number of dialects, sometimes very different from each other. Classification of modern I. (i.) i. proposed in the 80s. 19th century A. F. R. Hörnle and linguistically developed in the 20s. 20th century by J. A. Grierson. It is based on the distinction between “external” (peripheral) languages, which have a number of common features, and “internal” ones, where the corresponding features are absent (it is assumed that this division reflects, respectively, the early and late waves of migration of Aryan tribes to India, coming from the northwest ). “External” languages ​​are divided into northwestern [Lakhnda (Lendi), Sindhi], southern (Marathi) and eastern (Oriya, Bihari, Bengali, Assamese) subgroups. “Internal” languages ​​are divided into 2 subgroups: central (Western Hindi, Punjabi, Gujarati, Bhili, Khandeshi, Rajasthani) and Pahari (Eastern Pahari - Nepali, Central Pahari, Western Pahari). The intermediate subgroup includes Eastern Hindi. Indian linguists more often follow the classification of S. K. Chatterjee, who abandoned the distinction between “external” and “internal” languages ​​and emphasized the similarity of languages ​​occupying adjacent areas. According to this classification, which, in fact, does not contradict Grierson’s, northern, western, central, eastern and southern subgroups are distinguished. Occupies a special place gypsy language, which reveals a number of similarities with the languages ​​of northwestern India and Pakistan. I. (i.) I. outside India (Gypsy language in different countries, Parya dialect in Tajikistan, Sinhalese language in Sri Lanka, Maldivian language in the Republic of Maldives) show significant influence of foreign language systems.

Modern I. (i.) i. unite side by side common features, which are to a certain extent explained further development tendencies characteristic of prakrits, and the presence interlingual contacts, leading to the formation of various linguistic unions. The phonological systems of these languages ​​range from 30 to 50 or more phonemes (the number of phonemes gradually decreases in language areas from northwest to southeast). In general, the all-Indian phonological model is characterized by the presence of aspirated and cerebral consonants. Most common model consonantism includes 5 quadrangles: k-g, kh-gh; c-j, ​​ch-jh; ṭ-ḍ, ṭh-ḍh; t-d, th-dh; p-b, ph-bh (Hindi, Oriya, Bengali, Nepali, Marathi and Sindhi - in the last two languages ​​the general model is presented in an expanded form: in Marathi due to affricates, in Sindhi due to implosives). In Punjabi this is not a four-, but a three-term opposition (k-g-kh, etc., as in Dardic), in Sinhalese and Maldivian it is binary (k-g, etc., as in Tamil), in Assamese the model is the same fourfold, but there are no cerebral and palatal squares. The opposition of aspiration in voiced consonants is interpreted in a number of modern I. (i.) i. on the verge of inherent and prosodic(in Punjabi, Lendi, Western Pahari and East Bengali dialects this is a prosodic opposition of tones). In most languages ​​(except Marathi, Sinhala and Maldivian), the opposition of nasality is phonological for vowels; the long/short opposition is not phonological (except Sinhala and Maldivian). For modern I. (i.) I. in general, the absence of an initial combination of consonant phonemes is characteristic.

In the field of morphology, modern I. (i.) i. represent different stages of successive processes: loss of old inflection - development analytical forms - creating a new one based on them agglutinative inflection or a new synthetic inflection expressing a smaller range of meanings than the old inflection. Based on a typological study of the morphological structure of modern I. (i.) i. G. A. Zograf divides them into 2 types: “Western” and “Eastern”. In the “Western” type, grammatical meanings are conveyed by inflectional and analytical indicators, with the latter building up on the former, forming two- and three-tier formant systems (for names - an indirect base + postpositions, primary and derivatives; for a verb - a combination of participles or verbal names with auxiliary verbs , primary and secondary). In the “eastern” type, these meanings are conveyed mainly by agglutinative indicators, onto which analytical indicators can be built up, for example, in names - stem (= direct case) + [affix certainty or plurality] + case affix + [postposition]; for verbs - stem (= root) + tense affix + person affix. In the "Western" type there is grammatical category sort of, which usually includes two genders, less often three (Marathi, Gujarati), there is no such category in the “eastern” category. In the "Western" type adjectives are divided into 2 subclasses: mutable and immutable; in the “eastern” they are always immutable.

In the syntax for modern I. (i.) i. characterized by a fixed position of the verb (at the end of the sentence) and words associated with it, a wide distribution of function words (in the “Western” type - postpositions, in the “Eastern” type - special particles). The “Western” type is characterized by the development ergative or different options ergative design; They are unusual for the “eastern” type.

  • Zograf G. A., Languages ​​of India, Pakistan, Ceylon and Nepal, M., 1960;
  • his, Morphological structure of new Indo-Aryan languages, M., 1976;
  • Elizarenkova T. Ya., Studies on the diachronic phonology of Indo-Aryan languages, M., 1974;
  • Languages ​​of Asia and Africa, vol. 1, Indo-Aryan languages, M., 1976;
  • Chatterjee S.K., Introduction to Indo-Aryan linguistics, [trans. from English], M., 1977;
  • Beames J., A comparative grammar of the modern Aryan languages ​​of India: to wit, Hindi, Panjabi, Sindhi, Gujarati, Marathi, Oriya and Bangali, v. 1-3, L., 1872-79;
  • Hoernle R., A comparative grammar of the Gaudian languages, L., 1880;
  • Grierson G. A., Linguistic survey of India, v. 1-11, Calcutta, 1903-28;
  • Bailey T. G., Studies in North Indian languages, L., 1938;
  • Bloch J., Indo-Aryan from the Vedas to modern times, P., 1965;
  • Turner R. L., A comparative dictionary of the Indo-Aryan languages, L., 1962-69.

T. Ya. Elizarenkova.

One of the main tasks of geological research is determining the age of the rocks that make up the earth's crust. There are relative and absolute ages. There are several methods for determining the relative age of rocks: stratigraphic and paleontological.

The stratigraphic method is based on the analysis of sedimentary rocks (marine and continental) and determination of the sequence of their formation. The layers below are older, those above are younger. This method establishes the relative age of rocks in a certain geological section in small areas.

The paleontological method is the study of fossilized remains. organic world. The organic world has undergone significant changes in the course of geological history. Study of sedimentary rocks in vertical section earth's crust showed that a certain complex of layers corresponds to a certain complex of plant and animal organisms.

Thus, plant and animal fossils can be used to determine the age of rocks. Fossils are the remains of extinct plants and animals, as well as traces of their vital activity. To determine the geological age, not all organisms are important, but only the so-called leading ones, that is, those organisms that, in the geological sense, did not exist for long.

Leading fossils must have a small vertical distribution, a wide horizontal distribution, and good preservation. In each geological period, a certain group of animals and plants developed. Their fossilized remains are found in sediments of the corresponding age. In ancient layers of the earth's crust, remains of primitive organisms are found, in younger ones, highly organized ones. The development of the organic world occurred in an ascending line; from simple to complex organisms. The closer to our time, the greater the similarity with the modern organic world. The paleontological method is the most accurate and widely used.

Table composition

The geochronological scale was created to determine the relative geological age of rocks. Absolute age, measured in years, is of secondary importance to geologists. The existence of the Earth is divided into two main intervals: Phanerozoic and Precambrian (cryptozoic) according to the appearance of fossil remains in sedimentary rocks. Cryptozoic is a time of hidden life; only soft-bodied organisms existed in it, leaving no traces in sedimentary rocks. The Phanerozoic began with the appearance at the border of the Ediacaran (Vendian) and Cambrian of many species of mollusks and other organisms, allowing paleontology to subdivide the strata based on finds of fossil flora and fauna.

Another major division of the geochronological scale has its origins in the very first attempts to divide the history of the Earth into major time intervals. Then the whole history was divided into four periods: primary, which is equivalent to the Precambrian, secondary - the Paleozoic and Mesozoic, tertiary - the entire Cenozoic without the last Quaternary period. The Quaternary period occupies a special position. This is the shortest period, but many events took place in it, the traces of which are better preserved than others.

Based on stratigraphic and paleontological methods, a stratigraphic scale was constructed, presented in Fig. 1, in which the rocks that make up the earth's crust are located in a certain sequence in accordance with their relative age. This scale identifies groups, systems, departments, and tiers. Based on the stratigraphic scale, a geochronological table has been developed, in which the time of formation of groups, systems, divisions and stages is called an era, period, epoch, century.

Fig.1. Geochronological scale

The entire geological history of the Earth is divided into 5 eras: Archean, Proterozoic, Paleozoic, Mesozoic, Cenozoic. Each era is divided into periods, periods into eras, eras into centuries.

Features of determining the age of rocks

Absolute geological age is the time that has elapsed from any geological event to the modern era, calculated in absolute units of time (in billions, millions, thousands, etc. years). There are several methods for determining the absolute age of rocks.

The sedimentation method comes down to determining the amount of clastic material that is annually carried away from the surface of the land and deposited on the bottom of the sea. Knowing how much sediment accumulates on the seabed during the year and measuring the thickness of sedimentary strata accumulated in individual geological periods, one can find out the length of time required for the accumulation of these sediments.

The sedimentation method is not entirely accurate. Its inaccuracy is explained by the unevenness of sedimentation processes. The rate of sedimentation is not constant, it changes, intensifying and reaching a maximum during periods of tectonic activity of the earth's crust, when the earth's surface has highly dissected forms, due to which denudation processes intensify and, as a result, more sediment flows into marine basins. During periods of less active tectonic movements of the earth's crust, denudation processes weaken and the amount of precipitation decreases. This method gives only an approximate idea of ​​the geological age of the Earth.

Radiological methods the most accurate methods for determining the absolute age of rocks. They are based on the use of radioactive decay of isotopes of uranium, radium, potassium and other radioactive elements. The rate of radioactive decay is constant and does not depend on external conditions. The end products of the decay of uranium are helium and lead Pb2O6. From 100 grams of uranium, 1 gram (1%) of lead is formed in 74 million years. If we determine the amount of lead (in percent) in the mass of uranium, then by multiplying by 74 million we get the age of the mineral, and from it the lifetime of the geological formation.

IN Lately They began to use a radioactive method, which was called potassium or argon. In this case, the potassium isotope with atomic weight 40 is used. The potassium method has the advantage that potassium is widely distributed in nature. As potassium decomposes, calcium and argon gas are formed. The disadvantage of the radiological method is limited opportunity its applications are mainly for determining the age of igneous and metamorphic rocks.

Geochronological table- this is one way of representing the stages of development of planet Earth, in particular life on it. The table records eras, which are divided into periods, their age and duration are indicated, and the main aromorphoses of flora and fauna are described.

Often in geochronological tables earlier, i.e., older, eras are written at the bottom, and later, i.e., younger, eras are written at the top. Below is data on the development of life on Earth in natural chronological order: from old to new. The tabular form has been omitted for convenience.

Archean era

It began approximately 3500 million (3.5 billion) years ago. Lasted about 1000 million years (1 billion).

In the Archean era, the first signs of life on Earth appeared - single-celled organisms.

According to modern estimates, the age of the Earth is more than 4 billion years. Before the Archean there was the Catarchean era, when there was no life yet.

Proterozoic era

It began approximately 2700 million (2.7 billion) years ago. Lasted for more than 2 billion years.

Proterozoic - the era of early life. Rare and scarce organic remains are found in the layers belonging to this era. However, they belong to all types of invertebrate animals. Also, the first chordates most likely appear - skullless.

Palaeozoic

It began about 570 million years ago and lasted more than 300 million years.

Paleozoic - ancient life. Starting with it, the process of evolution is better studied, since the remains of organisms from higher geological layers are more accessible. Hence, it is customary to examine each era in detail, noting changes in the organic world for each period (although both the Archean and the Proterozoic have their own periods).

Cambrian period (Cambrian)

Lasted about 70 million years. Marine invertebrates and algae thrive. Many new groups of organisms appear - the so-called Cambrian explosion occurs.

Ordovician period (Ordovician)

Lasted 60 million years. The heyday of trilobites and crustaceans. The first vascular plants appear.

Silurian (30 Ma)

  • Coral blossom.
  • The appearance of scutes - jawless vertebrates.
  • The appearance of psilophyte plants coming onto land.

Devonian (60 Ma)

  • The flourishing of the corymbs.
  • Appearance of lobe-finned fishes and stegocephali.
  • Distribution of higher spores on land.

Carboniferous period

Lasted about 70 million years.

  • The rise of amphibians.
  • The appearance of the first reptiles.
  • The appearance of flying forms of arthropods.
  • Decline in trilobite numbers.
  • Fern blossoming.
  • The appearance of seed ferns.

Perm (55 million)

  • Distribution of reptiles, emergence of wild-toothed lizards.
  • Extinction of trilobites.
  • Disappearance of coal forests.
  • Distribution of gymnosperms.

Mesozoic era

Era average life.

Geochronology and stratigraphy

It began 230 million years ago and lasted about 160 million years.

Triassic

Duration - 35 million years. The flourishing of reptiles, the appearance of the first mammals and true bony fish.

Jurassic period

Lasted about 60 million years.

  • Dominance of reptiles and gymnosperms.
  • The appearance of Archeopteryx.
  • There are many cephalopods in the seas.

Cretaceous period (70 million years)

  • The appearance of higher mammals and true birds.
  • Wide distribution of bony fish.
  • Reduction of ferns and gymnosperms.
  • The emergence of angiosperms.

Cenozoic era

An era of new life. It began 67 million years ago and lasts the same amount.

Paleogene

Lasted about 40 million years.

  • The appearance of tailed lemurs, tarsiers, parapithecus and dryopithecus.
  • Rapid flourishing of insects.
  • The extinction of large reptiles continues.
  • Entire groups of cephalopods are disappearing.
  • Dominance of angiosperms.

Neogene (about 23.5 million years)

Dominance of mammals and birds. The first representatives of the genus Homo appeared.

Anthropocene (1.5 Ma)

The emergence of the species Homo Sapiens. Animal and vegetable world takes on a modern look.

In 1881, at the II International Geological Congress in Bologna, the International Geochronological Scale was adopted, which is a broad systematic synthesis of the work of many generations of geologists in various fields of geological knowledge. The scale reflects the chronological sequence of time divisions during which certain complexes of sediments and the evolution of the organic world were formed, i.e. the international geochronological scale reflects the natural periodization of the history of the Earth. It is built on the principle of rank subordination of time and stratigraphic units from larger to smaller (Table 6.1).

Each temporary division corresponds to a complex of sediments, distinguished in accordance with changes in the organic world and called a stratigraphic division.

Therefore, there are two scales: geochronological and stratigraphic (Tables 6.2, 6.3, 6.4). In these scales, the entire history of the Earth is divided into several eons and their corresponding eonotemes.

Geochronological and stratigraphic scales are constantly changing and improving. The scale given in table. 6.2, has an international rank, but it also has options: instead of the Carboniferous period on the European scale, in the USA there are two periods: the Mississippian, which follows the Devonian, and the Pennsylvanian, which precedes the Permian.

Each era (period, epoch, etc.) is characterized by its own complex of living organisms, the evolution of which is one of the criteria for constructing a stratigraphic scale.

In 1992, the Interdepartmental Stratigraphic Committee published a modern stratigraphic (geochronological) scale, which is recommended for all geological organizations in our country (see Tables 6.2, 6.3, 6.4), but it is not generally accepted on a global scale; the greatest disagreements exist for the Precambrian and for the Quaternary system.



Notes.

Highlighted here:

1. Archean eon (AR) (ancient life), to which the stratigraphic mass of rocks corresponds - the Archean eonothem.

2. Proterozoic eon (PR) (primary life) - it corresponds to the stratigraphic strata of rocks - the Proterozoic eonothem.

3. Phanerozoic eon, divided into three eras:

3.1 - Paleozoic era (PZ) (era ancient life) - it corresponds to the Paleozoic rock strata - Paleozoic erathema (group);

3.2 - Mesozoic era (MZ) (era of middle life) - it corresponds to the Mesozoic rock mass - Mesozoic erathema (group);

3.3 - Cenozoic era (KZ) (era of new life) - it corresponds to the Cenozoic rock formation - Cenozoic erathema (group).

The Archean eon is divided into two parts: the early (older than 3500 million years) and the late Archean. The Proterozoic eon is also divided into two parts: early and late Proterozoic; in the latter the Riphean (R) is distinguished (according to ancient name Ural - Ripheus) and Vendian period (V) - named after the ancient Slavic tribe “Vedas” or “Vendas”.

The Phanerozoic eon and eonothem are divided into three eras (eratems) and 12 periods (systems). The names of the periods are usually assigned to the name of the area where they were first identified and most fully described.

In the Paleozoic era (erathema) are allocated accordingly.

1. Cambrian period (6) - Cambrian system (Є) - after the ancient name of the province of Wales in England - Cambria;

2. Ordovician period (O) - Ordovician system (O) - after the name of the ancient tribes of England that inhabited those areas - “Mordovians”;

3. Silurian period (S) - Silurian system (S) - after the name of the ancient tribes of England - “Silurians”;

4. Devonian period (D) - Devonian system (D) - after the name of the county of Devonshire in England;

5. Carboniferous (Carboniferous) period (C) - Carboniferous (Carboniferous) system (O - by the widespread development of coal deposits in these deposits;

6. Permian period (P) - Permian system (P) - after the name of the Perm province in Russia.

In the Mesozoic era (erathema) are allocated accordingly.

1. Triassic period (T) - Triassic system (T) - by dividing the period (system) into three parts;

2) Jurassic period (J) - Jurassic system (J) - named after the Jurassic Mountains in Switzerland;

3. Cretaceous period (K) - Cretaceous system (K) - according to the widespread development of writing chalk in the deposits of this system.

In the Cenozoic era (erathema) are allocated accordingly.

1. Paleogene period (P) - Paleogene system (P) - the most ancient part of the Cenozoic era;

2. Neogene period (N) - Neogene system (N) - newborns;

3. Quaternary period (Q) - Quaternary system (Q) - according to the proposal of academician.

Geochronological scale

A.A. Pavlova, sometimes called the Anthropocene.

Indices (symbols) of eras (erathems) are designated by the first two letters of Latin transcription, and periods (systems) by the first letter.

On geological maps and sections for the convenience of depicting each age system assigned a specific color. Periods (systems) are divided accordingly into epochs (divisions). The duration of geological periods varies - from 20 to 100 million years. The exception is the Quaternary period - 1.8 million years, but it has not ended yet.

Early, middle, late eras correspond to the lower, middle, upper sections. There may be two or three eras (departments). The indices of eras (departments) correspond to the index of their periods (systems) with the addition of numbers at the bottom right - 1,2,3. For example, 5, is the Early Silurian era, and S2 is the Late Silurian era. To color designate eras (divisions), the color of their periods (systems) is used for earlier (later) - darker shades. Epochs (departments) Jurassic period and the Cenozoic era retained their own names. The stratigraphic and geochronological units of the Cenozoic era (groups) have their own names: P1 - Paleocene, P2 - Eocene, P3 - Oligocene, N1 - Miocene, N2 - Pliocene, QI, QII, QIII - epochs (divisions) early (lower), middle (mid-), late Quaternary (upper Quaternary) - together called the Pleistocene, and Q4 - Holocene.

The next and more fractional units of the geochronological and stratigraphic scales are centuries (stages) lasting from 2 to 10 million years. They are given geographical names.

1. Geological time scale

1.5. Geochronological and stratigraphic scales.

Irreversibility of time

3. Natural history of the Middle Ages

List of used literature

1. Geological time scale

Physical, cosmological, chemical concepts lead close to ideas about the Earth, its origin, structure and various properties. The complex of geosciences is usually called geology(Greek ge – Earth). Earth is a place and necessary condition existence of humanity. For this reason, geological concepts are of the utmost importance to humans. We have to understand the nature of their evolution. Geological concepts do not arise spontaneously; they are the result of painstaking scientific research.

The Earth is a unique space object. The idea of ​​the evolution of the Earth occupies a central place in his study. Taking this into account, let us turn, first of all, to such an important quantitative-evolutionary parameter of the Earth as its time, geological time.

The development of scientific concepts about geological time is complicated by the fact that the lifespan of a human individual is a tiny fraction of the age of the Earth (approx. 4.6 * 109 years). Simple extrapolation of current geological time into the depths of past geological time gives nothing. To obtain information about the geological past of the Earth, some special concepts are needed. There are a variety of ways to think about geological time, chief among them lithological, biostratigraphic, and radiological.

The lithological concept of geological time was first developed by the Danish physician and naturalist N. Stensen (Steno). According to the concept of Steno (1669), in a series of normally occurring strata, the overlying strata are younger than the underlying ones, and the cracks and mineral veins cutting them are even younger. main idea The point is this: the layered structure of rocks on the Earth's surface is a spatial reflection of geological time, which, of course, also has a certain structure. In the development of Steno's ideas, geological time is determined by the accumulation of sediments in the seas and oceans, river sediments in the estuarine areas of the coast, by the height of dunes, and by the thicknesses of “ribbon” clays that appear at the edges of glaciers as a result of their melting.

In the biostratigraphic understanding of geological time, the remains of ancient organisms are taken into account: the fauna and flora lying higher are considered younger. This pattern was established by the Englishman W. Smith, who compiled the first geological map of England dividing rocks by age (1813-1815). It is important that, unlike lithological layers, biostratigraphic features extend over long distances and are present throughout the entire shell of the Earth as a whole.

Based on litho- and biostratigraphic data, attempts have been made repeatedly to create a unified (bio)stratigraphic scale of geological time. However, along this path, researchers have invariably encountered indefinable difficulties. Based on (bio)stratigraphic data, it is possible to determine the “older-younger” relationship, but it is difficult to determine how many years one layer formed before the other. But the task of ordering geological events requires the introduction of not only ordinal, but also quantitative (metric) characteristics of time.

In the radiological measurement of time, in the so-called isotope chronology, the age of geological objects is determined based on the ratio of the parent and daughter isotopes of the radioactive element in them. The idea of ​​radiological time measurement was proposed at the beginning of the twentieth century. P. Curie and E. Rutherford.

Isotope geochronology has made it possible to use in procedures for measuring geological time not only ordinal definitions of the “earlier - later” type, but also quantitative determinations. In this regard, the geological time scale is introduced, which is usually presented in different versions. One of them is given below.

Intervals of geological time (beginnings of periods and epochs in millions of years from the present)

In the names of geological periods, only two expressions have been preserved from their early classification: Tertiary and Quaternary. Some of the names of geological periods are associated either with localities or with the nature of material deposits. So, Devonian The period characterizes the age of sediments first studied in Devonshire in England. Chalky period characterizes age characteristics geological deposits containing a lot of chalk.

2. Irreversibility of time

Time – this is a form of existence of matter, expressing the order of change in objects and phenomena of reality. Characterizes the actual duration of actions, processes, events; denotes the interval between events.

Unlike space, to each point of which you can return again and again, time – irreversible And one-dimensionally. It flows from the past through the present to the future. You cannot go back to any point in time, but you cannot jump over any time period into the future. It follows that time constitutes, as it were, a framework for cause-and-effect relationships. Some argue that the irreversibility of time and its direction are determined by cause and connection, since the cause always precedes the effect. However, it is obvious that the concept of precedence already presupposes time. Therefore, G. Reichenbach is more correct when he writes: “Not only the temporal order, but also the unified space-time order is revealed as an ordering scheme governing causal chains, and thus as an expression of the causal structure of the universe.”

The irreversibility of time in macroscopic processes is embodied in the law of increasing entropy. In reversible processes, entropy remains constant, in irreversible processes it increases. Real processes are always irreversible. In a closed system, the maximum possible entropy corresponds to the onset of thermal equilibrium in it: temperature differences in individual parts of the system disappear and macroscopic processes become impossible. All the energy inherent in the system is converted into the energy of disordered, chaotic movement of microparticles, and the reverse transition of heat into work is impossible.

It turned out that time cannot be considered as something separately taken. And in any case, the measured value of time depends on the relative movement of the observers. Therefore, two observers moving relative to each other and watching two different events will come to different conclusions about how separated the events are in space and time. In 1907, the German mathematician Hermann Minkowski (1864-1909) suggested a close connection between three spatial and one temporal characteristics. In his opinion, all events in the Universe occur in a four-dimensional space-time continuum.