The North American platform is an analogue of which platform. Geological structure, relief, minerals of South America

Bolivian hemorrhagic fever (South American hemorrhagic fever) Bolivian hemorrhagic fever is a naturally occurring viral disease endemic to the central provinces of Bolivia. Characterized by high fever, hemorrhagic

South American Platform South American platform

(Brazilian platform), a Precambrian platform occupying central and eastern South America. The basement protrudes to the surface within the Guiana and Brazilian shields.

SOUTH AMERICAN PLATFORM (Brazilian Platform), Precambrian (cm. PRECAMBRIAN) platform occupying the central and eastern parts of the South. America. The foundation protrudes to the surface within the Guiana (cm. GUIANA SHIELD) and Brazilian shields (cm. BRAZILIAN SHIELD).

encyclopedic Dictionary. 2009 .

See what the “South American platform” is in other dictionaries:

- (Brazilian platform) Precambrian platform occupying the central and eastern parts of the South. America. The basement protrudes to the surface within the Guiana and Brazilian shields... Big Encyclopedic Dictionary

See Art. South America. Mountain encyclopedia. M.: Soviet Encyclopedia. Edited by E. A. Kozlovsky. 1984 1991 … Geological encyclopedia

South American Platform- South American platform form... Russian spelling dictionary

- (geol.) ancient platform in the central and eastern parts of the continent of the same name. See South America, section Geological structure and minerals...

SOUTH... First part difficult words. Introduces the meaning: southern, located to the south, in the south. South Australian (but South Australian Basin), South American (but South American Platform), South African (but South African Republic),... ... encyclopedic Dictionary

south...- the first part of compound words. introduces the meaning: southern, located to the south, in the south. South Australian (but South Australian Basin), South American (but South American Platform), South African (but South African Republic), South China (but... ... Dictionary of many expressions

Platform (geological), one of the main types of structural elements earth's crust(lithosphere); large (several thousand km in diameter), relatively stable blocks of crust of consistent thickness, characterized by a very low degree... ... Great Soviet Encyclopedia

I Platform (French plate forme, from plat flat and forme form) 1) elevated platform, platform. 2) Small f. d. station, stop. 3) Freight car open type with small sides. 4) See Platform... ... Great Soviet Encyclopedia

See South American Plate. * * * BRAZILIAN PLATFORM BRAZILIAN PLATFORM, see South American Platform (see SOUTH AMERICAN PLATFORM) ... encyclopedic Dictionary

South American Platform, an ancient platform with mainly Precambrian basement, occupying almost the entire extra-Andean part of the South continent. America. About geol. for the structure of the B. p. see Art. South America. Mountain encyclopedia. M.: Soviet... ... Geological encyclopedia

This platform experienced a short-term uplift at the beginning of the Silurian as a result of the manifestation of the Taconic phase of folding in the Appalachian geosyncline. Regression gave way to transgression With wide distribution of carbonate sediments and reef formations.

Silurian deposits are represented by limestones and dolomites. In the Lower Silurian sections there are many reef structures; in the Upper Silurian, halogen rocks appear, especially in the east of the platform - anhydrites, gypsum and rock salt.

At the very end of the Silurian, huge salt basins arose in North America. The thickness of the Silurian is measured at several hundred meters. In depressions it increases, for example, in the Michigan Trench - up to 1.5 km.

Gondwana

The southern continents in the Silurian are still above sea level, and Silurian sediments are insignificant, but where they exist (on the periphery of Gondwana), they are represented by terrigenous formations.

In the South American part of Gondwana, at the end of the Ordovician - the beginning of the Silurian, a restructuring occurred, probably caused by the influence of Caledonian folding. In the Silurian, the area of ​​the sea increased. Depressions of a meridional direction appeared. They accumulated significant thickness (up to 800-1200 m) of clastic sediments with subordinate carbonate layers. In the Amazon basin (latitudinal direction) marine sandy-clayey sediments with a thickness of 100 m are observed. In the late Silurian and the very beginning of the Devonian, uplifts occurred again as a consequence of the Late Caledonian movements.

In the African part of Gondwana, sandy strata at the end of the Ordovician and Silurian were replaced by dark clays with graptolites. Carbonate silts appeared in the northern part of the basin. Coastal sands were deposited along the margins of the marine accumulation area. The thickness of Silurian rocks is usually small. On Arabian Peninsula The Silurian is represented by a continuous section of sandy-clayey formations of considerable thickness. At the end of the Silurian, regression began everywhere in Africa, especially clearly manifested in Arabia.

The Australian part of Gondwana in the Silurian was predominantly land.

History of the development of geosynclinal belts North Atlantic geosynclinal belt

Grampian geosynclinal region. Grampian geosyncline. A cross-section of the Silurian of Wales, the stratotype area where the Silurian system was identified, can be seen in diagram III, color. on

The Silurian overlies the Ordovician with a structural unconformity caused by the Taconic folding. At the base of the Llandovery lie conglomerates and sandstones, which are replaced higher up by sandy-clayey strata with shell rocks; Pentamerids are numerous (the thickness of Llandovery reaches 1.5 km). Wenlock is lithologically diverse: V In some areas, calcareous-clayey rocks and

limestones with remains of brachiopods and corals (300-400 m), in others there is a thick sequence of sandstones and siltstones (thickness -1.2 km). Ludlovsky deposits are predominantly carbonate: limestones, calcareous shales, calcareous siltstones. Stromatoporates, corals, and brachiopods are numerous (thickness - 0.5 km). There are fossil banks with Conchidium knighti. In the upper part of the tier there is a layer of so-called bone-bearing breccia, consisting of parts and fragments of the bone cover of armored fish.

The described section of three tiers refers to “shell” formations - shallow-water deposits of considerable thickness containing the indicated fauna.

Another type of section of the same stages is also known - in the form of a thin sequence of graptolite shales. In this case, clayey material was deposited in deep-sea areas. The third type of cut is mixed. It contains breeds of the first and second types.

The uppermost part of the Silurian section in England is distinguished as the Downtonian stage (thickness -0.6-0.9 km). These are red and variegated sandy-clayey rocks with interlayers of red marls. They contain shells of ostracods and ichthyofauna. Gradually, the Downtonian is replaced by the Lower Red-colored Devonian. All this is overlapped with structural unconformity by Middle Devonian conglomerates.

In Wales the total thickness of the Silurian is 3 km. The sediments are folded and metamorphosed. The Caledonian folding manifested itself repeatedly and was accompanied by magmatism.

In the Scandinavian part of the Grampian geosyncline, thick clastic strata accumulated, initially typically marine, and by the end of the Silurian - continental.

Ural-Mongolian geosynclinal belt

Ural-Tien-Shan geosynclinal region stretches from Novaya Zemlya to the southern Tien Shan.

Ural geosyncline. Silurian deposits are widely developed in the Urals. On the western slope of the Urals there was a quiet accumulation of carbonate and terrigenous sediments (up to 2 km) in miogeosynclinal conditions. On the eastern slope, in the eugeosyncline, lavas and tuffs, siliceous shales and limestones accumulate (thickness - 5 km). In the Silurian in the Urals, the main geotectonic structures were laid down, which later turned into the existing anticlinoria and synclinorium. The Silurian of the Urals on the western and eastern slopes contains the same fauna, which indicates a single geosynclinal Ural basin in the Silurian. ,; On the territory of the western slope of the Urals and on Novaya Zemlya, miogeosynclinal conditions prevailed, so carbonate and carbonate-clay deposits (500-1500 m) with a diverse complex of organic remains accumulated here. Shallow coastal sand and pebble rocks are known on the western edge of the Northern Urals (Polyudov Ridge). In the west of the central part of the Urals, on Pai-Khoi and in places on Novaya Zemlya, black clayey graptolite shales are exposed.

The Caledonian folding, in contrast to other geosynclines of the Ural-Mongolian belt, is not typical for the Urals; it did not cause structural unconformities, but the ultrabasic and basic intrusions of the central zone are considered Caledonian.

Silurian deposits are widespread in Kazakhstan part of the Ural-Mongolian belt. They are represented by typical geosynclinal formations of considerable thickness with the remains of a rich fauna. Characteristic horizons are brachiopod and coral limestones.

In the context of the ridge. Chingiztau Silurian is represented only by the lower section (see diagram III, color on). Silurian sediments (up to 2.5 km) accumulated in eugeosynclinal marine environments with strong volcanism. The Caledonian folding was actively manifested. The most pronounced is the last - Late Caledonian - phase of folding, which led to the retreat of the sea from the territory of the Chingiztau Ridge, to the completion of the first, actually geosynclinal, stage of its development.

Tia. The shallow-lying Lower and Middle Devonian effusives and felsic tuffs crowning the section accumulated already in terrestrial conditions. They are usually isolated into volcanogenic molasse of the orogenic stage of development. The repeated intrusion of large granitoid intrusions is associated with folding.

Altai-Sayan folded region. Silurian deposits are known in the same place as the Ordovician, but in the west limestones and terrigenous rocks with a rich fauna predominate, in the east (Western Sayan, Tuva) the role of coarse clastic rocks with a depleted fauna increases. The thickness of Silurian deposits in the west is 4.5 km, in the east - up to 7.5 km.

In the Silurian section of Western Tuva (see diagram III, color incl.), Silurian deposits (Chergak series) lie conformably on Ordovician ones. They are thick (2.5-3 km) and consist of sandy-clayey rocks with interlayers, packs and lenses of limestone. The highest carbonate content is confined to the middle part of the section. The fauna is rich and diverse. These are stromatoporates, tabulates, heliolitids, rugosas, crinoids, bryozoans, brachiopods, trilobites. Many local (endemic) forms. Obviously, in the Silurian there existed a shallow sea basin with small reefs, coral and crinoid thickets, and banks of brachiopods. The endemism of the fauna indicates difficult communication with other seas. By the end of the Silurian, the basin gradually shrank, became shallow, its salinity changed, and only euryhaline organisms survived in it.

In the Ordovician, Silurian and early Devonian in Western Tuva, a single huge (10 km) transgressive-regressive Tuvan complex was formed with marine sediments in the middle part and red continental rocks in the base and roof. The deposits of the Tuvan complex are folded and intruded by small basic and acidic intrusions. The upper part of the section under consideration is composed of thick terrestrial effusives of the Lower Devonian and red clastic rocks of the Middle Devonian. These are continental deposits of intermountain basins, formed during regression caused by the Caledonian folding. - "In the section of Western Tuva, three structural floors, sharply different from each other, are clearly distinguished: the first is the Lower Cambrian; the second is the Ordovician, Silurian, lower Devonian; the third is the upper part of the Lower Devonian and the Middle Devonian. The floors are recorded different stages geological development: the first is eugeosynclinal, the third is orogenic, and the second is intermediate (transitional). At the second stage, subsidence developed on an already consolidated foundation; the regime resembled a miogeosynclinal one. Ore deposits of iron and copper are associated with acidic intrusions.

Thus, the Caledonian era of tectogenesis covered areas of northwestern Kazakhstan, partly the Altai Mountains, northern Tien Shan and eastern part Altai-Sayan folded region - Western Sayan and Tuva, where the Caledonides arose.

Mediterranean geosynclinal belt

In the European part of this belt, conditions close to those previously described in the Ordovician are preserved. This is still the island land of the Franco-Bohemian massif (Moldanuba block) and the marine conditions to the north and south of it (Prague synclinorium, see diagram III, color on). IN northern Europe sandstones, black clay shales, bituminous limestones accumulate (thickness - 0.5 km), siliceous shales appear, due to manifestations of underwater volcanic activity. IN southern Europe, between the Franco-Bohemian massif and the Atlas Mountains in Africa, the Silurian is represented by monotonous facies: black shales with graptolites, giving way to limestones at the tops of the section.

IN Asian geosynclinal region Silurian is known in Turkey, the Caucasus, in the mountain structures of Iran, Afghanistan, and the Pamirs.

Here, under eugeosynclinal conditions, thick strata of terrigenous rocks and volcanics of basic and acidic composition accumulated, or low-thickness terrigenous-carbonate facies accumulated in miogeosynclinal zones (Zagros Himalayas, etc.).

Minerals

Deposits rock salt, industrial deposits oil And gas known in North American (Canadian) and Siberian platforms. Oolitic deposits formed in the Silurian iron ores Clinton (USA) and a number of small ones in Africa. Deposits associated with Caledonian acid intrusions gold Northern Kazakhstan, Kuznetsk Alatau and Mountain Shoria.

Found in Late Caledonian intrusions in the Scandinavian mountains iron, copper, chromite: Known in the Urals nickel, platinum, asbestos, jasper. Deposits associated with pegmatites rare metals in the Appalachians and Eastern Siberia.

Silurian limestones are a building material and a good ceramic raw material.

DEVONIAN PERIOD - D

General characteristic, stratigraphic divisions and stratotypes

The Devonian system was established in 1839 by the famous English geologists A. Sedgwick and R. Murchison in England in the county of Devonshire, after which it was named.

The duration of the Devonian period is 48 million years, its beginning is 408 million years ago, and its end is 360 million years ago.

"The Devonian sections of Great Britain are composed of continental facies and can be combined with stratotypes to distinguish stages. Therefore, the division of the Devonian system was carried out in the Ardennes in Belgium, France and in the Rhine Slate Mountains in Germany. The Devonian system is divided into three sections (Table 8).

Table 8 General stratigraphic units of the Devonian system

The boundary between the Silurian and Devonian, as mentioned above, is drawn at the base of the graptolite zone Monograptus uniformis(Barrandien, Czech Republic). Currently, this boundary is the only one officially accepted by the Stratigraphic Commission of the International Geological Congress. Upper limit not officially approved. Due to the fact that at the beginning of the Devonian period the extensive regression that began in the Silurian continued, many different facial settings with corresponding fauna arose. This greatly complicates the division and comparison of sections and was the reason for the creation of a “composite” scale, consisting of tiers installed in different regions. The stage division of the Lower Devonian of Barrandien and the Rhineland is based on the marine fauna, and the age-appropriate sediments of England - on the remains of fish found in lagoonal-continental sediments.

Zhedino stage, named by A. Dumont in 1848 after the river. Zhedin in the Ardennes, unites the lower layers of the Devonian of the Ardenno-Rhine region. They are represented by coastal facies and overlie Cambrian deposits transgressively (hence the difficulty in determining the exact boundary with the Silurian). In the stratotype Bottom part It is represented by Fepan conglomerates with a thickness of 10-40 m, Ebb arkoses with a thickness of 30 m and Mondrechon shales with sandstone interlayers. Sandstones and shales contain rich brachiopod assemblages. In the upper part there are red and burgundy shales with small calcareous concretions; interlayers of red

and green sandstones and quartzites. They are characterized by fish remains. The total thickness is 750 m.

The name “Siegenian Stage” was first used by E. Kaiser, denoting the greywackes in the Rhine Slate Mountains. The Siegen greywackes are most fully represented in the Siegerland region, where lagoonal and coastal-marine facies with remains of fish, bivalves and brachiopods are developed. The thickness of the deposits in the stratotype section is 4 km.

The Emsian Stage was established by K. Dorlodo in 1900 in the town of Ems near Koblenz in the Rhineland. The deposits of this stage are represented by a sequence of sandstones, quartzites and shales with interlayers of volcanic rocks. The thickness reaches 2 km. The layers contain accumulations of brachiopods, bivalves, and occasionally corals (Fig. 51).

Previously, the Siegen and Emsian stages were combined into one stage, which was called the Koblenzian. However, according to the decision of the International Stratigraphic Commission, the Lower Devonian is now accepted as three stages.

The Eifelian stage was named by A. Dumont in 1848 after the Eifel Mountains, where the stratotype section is located. The volume of the stage was modified and, after the work of M. Düsseldorf in 1937, it was accepted as the volume of calceolic and upper culture-jugate Lauch layers with a stratotype in the Wetteldorf section of the Eifel Mountains. Here a succession of marls, platy limestones, calcareous sandstones and coral-stromatoporoid limestones (about 450 m thick) is exposed. In the thickness there are large numbers of corals of the genera Favosites, Calceola, Damophyllum, remains of cephalopods and conodonts.

The Givetian Stage was identified in the Ardennes by J. Gossel in 1879. The name comes from the city of Givet, located in Northern France. This stage unites deposits characterized by stringocephalic brachiopods, the presence of conodonts, corals and, less commonly, trilobites. The stage is composed of limestones and calcareous shales, organogenic and organogenic-clastic limestones.

The Frasnian stage was established in 1879 by J. Gossel in Belgium. Got its name from the village. Fran near the city of Kouven. In the stratotype section it is composed of shales and reef coral-stromato-porous limestones (about 500 m thick). Characterized by brachiopods, conodonts, corals and bivalves.

* The Famennian Stage was first identified in the Ardennes by A. Dumont in 1855. It received its name from the Famennian area in Belgium. Sandstones and shale with interlayers of limestone are developed here. In stratospheric terrain it is characterized by great variability. Marine sediments contain conodonts, corals and brachiopods, while lagoon sediments contain fish remains and plant imprints.

In the 60s, Czechoslovak researchers proposed to distinguish the Lochkovian and Prague stages instead of the Zedino and Siegen, established in the marine sections of the Barrandova Trough in the Bohemian Massif, not far from Prague, which were perfectly characterized by fauna. Here is also the recognized boundary of the Silurian and Devonian, drawn between the Przydolian and Lochkovian stages. In 1985, the International Subcommission on Devonian Stratigraphy recommended the Lochkovian and Prague stages of the Czech Republic as type stages for the lower Devonian. Since then, geologists have used precisely these stages, although the former Zhedino and Siegen stages approximately corresponding to them have not been formally abolished. This explains the “dual power” at the bottom of the tier scale of the Devonian system.

Typical sections of the Devonian system are presented in diagrams IV and V, color. on

Organic world

The organic world of the Devonian period was rich and diverse. Made significant progress ground vegetation. The beginning of the Devonian period was characterized by a wide distribution of “psilaphytes” (rhiniophytes), which reached their greatest prosperity at that time

Rice. 51. Characteristic fossil remains of Devonian organisms

Brachiopods:/ - Euryspirifer(Early and Middle Devonian), 2a, 6 - Stringocephalus(average Devonian), 3 -Karpinskia(Early Devonian), 4 - Cyrtospirifer(mostly Late Devonian), 5a, b - Hypothyridina(Middle and Late Devonian); cephalopods:6 - Clymenia(Late Devonian), 7 - Timanites(late Devonian), 8 -Tornoceras(Late Devonian); crinoids:9 - Cupressocrinites(Middle Devonian); rugosa corals:10 - Calceola(Early - Middle Devonian), // - Hexagonaria(Middle - Late Devonian); conodonts:12 - Palmatolepis(late Devonian), 13 - Polygnathus(Devonian), 14 - Icriodus(Devonian); lungfish:15 - Dipterus(Middle - Late Devonian); lobe-finned fish:16 - Holoptychius(Late Devonian); amphibians:17 - Ichthyostega(Late Devonian); rhyniophytes:18 - Rhynia(Early Devonian), 19, 20 - Sawdonia(Early Devonian)

(Fig. 52, color included). Their dominance is observed in wetland landscapes. At the beginning of the Middle Devonian, rhyniophytes died out and were replaced by proto-ferns, which began to develop leaf-like forms. In the Middle Devonian, all the main groups already existed spore plants. These are lycophytes, arthropods and ferns, and at the end of the Devonian the first representatives of gymnosperms appeared; many of the shrubby ones turned into tree-like ones and gave rise to the first layers of coal (Spitsbergen, Barzas). The Late Devonian flora was called Archaeopteris, after the widespread heterosporous fern Archaeopteris(Fig. 53, color included). At the end of the Devonian, forests consisting of the plants listed above already existed on the planet.

Conodonts are of greatest biostratigraphic importance in the Devonian. These representatives of primitive chordates, which appeared in the Middle Cambrian, already gained a dominant position in the Ordovician. In the Late Devonian, their second peak of flowering was observed. Conodonts changed so quickly in the Devonian that they make it possible to distinguish more than 50 standard zones in Devonian deposits with a duration of the Devonian period of about 50 million years. This is a striking example of using the remains of rapidly evolving organisms to create ultra-detailed stratigraphy. w Graptolites survive in the Devonian (one genus rarely found in the Lower Devonian Monograptus) and cystoids; The diversity of forms of trilobites and nautiloids is sharply reduced. Castle brachiopods (brachiopods) from the family Spiriferiidae with the main genus are widespread Spirifer and pentamerides (genus Pentamerus), four-rayed corals, tabulates.

Of significant importance are the cephalopods (Fig. 51): the orders Goniatita, Agonyatita and Clymenia. They have a simple septal line with solid pointed lobes and solid rounded saddles (goniatite), or with rounded lobes and saddles (agoniatite). Clymenia are a specific group of ancient ammonoids, in which the siphon was located closer to the dorsal side, and not to the ventral side, as in most representatives of the ammonoid subclass. Clymenia were characteristic exclusively of the Late Devonian.

For the first time in the history of the Earth, bivalves and some lower crustaceans began to play a major role, which is associated with the existence of numerous basins of abnormal salinity in the Devonian. It should be noted the abundance of the smallest crustaceans - ostracods and phyllopods.

For the stratigraphy of marine sediments, the most important are conodonts, ammonoids, brachiopods, corals, tentaculites and ostracods. Vertebrates began to acquire increasing importance. Jawless fish and especially fish are widespread: lungfish, armored fish, lobe-finned fish, cartilaginous fish (sharks, rays) (Fig. 51). In freshwater and brackish water basins, fish were apparently already numerous. The first amphibians, stegocephalians, are known from the Devonian.

The development of land by plants and animals continued. Among the latter there are scorpions and centipedes, which appeared in the Silurian, as well as wingless insects.

Crustal structures and paleogeography v

During the Devonian period there are no significant changes in the distribution and outline of the main structural elements of the earth's crust created by the beginning of the Devonian (platforms, geosynclinal belts and Caledonides). This is explained by the weak development of folding processes in the Devonian, which are characterized by low intensity. Only at the end of the period did it appear in some geosynclinal areas Breton folding phase - beginning Her-cyn era of tectonogenesis. The Breton folding phase is established in the north-west of the Mediterranean (European) geosynclinal region (Brittany Peninsula) and in the South Appalachian geosynclinal region. The Caledonian folding led to uplifts of not only the Caledonides regions, but also many platforms. Reached its maximum in the Early Devonian regression, which began at the end of the Silurian. The areas of destruction and demolition were the Caledonides and extensive pro-.

platform wanderings. Sedimentation on the platforms decreased sharply; it continued only in areas bordering the Caledonides. This stage is characterized by inland water bodies with abnormal salinity. The marine regime has been preserved in geosynclines.

From the mid-Devonian, in many areas of the world, ascending movements gave way to subsidence, and a new transgression developed. The sea advanced on the platforms and penetrated into the Caledonides (see diagram IV, color on).

At the end of the Late Devonian, in the Famennian Age, the uplift of the platforms began again (Breton phase) and, in connection with this, some regression of the sea.

; A characteristic feature of the Devonian is the formation of intermountain depressions in which continental terrigenous, predominantly red-colored sediments and volcanics several thousand meters thick accumulated. The deposits of intermountain depressions are collected in folds or lie flat. In some depressions they are broken through by intrusions and metamorphosed to varying degrees. The appearance of depressions is associated with the emergence and activation of faults, with block movements characteristic of the Devonian. The formation of such depressions occurred during the final - orogenic- stage of development of geosynclines.

The beginning of the Devonian period (Early Devonian era) deserves the name geocratic eras in the life of the Earth, that is, eras with a predominance of the continental regime. Since the Middle Devonian era, the areas occupied by seas have increased, both on platforms and in geosynclinal areas. The land area is decreasing. At the same time, a general leveling occurs, a gradual peneplanation continents, as well as island land areas scattered across geosynclinal areas. This is evidenced by the almost universal change from terrigenous sedimentation, characteristic of the Early Devonian, to carbonate. Until the end of the Devonian period mountainous terrain was preserved most consistently in the Caledonian regions, but even there, by the end of the period, it turned out to be significantly smoothed out in places, as evidenced by the relative fine-grained upper layers of “ancient red sandstone” of the British Isles, Minusinsk depressions, etc. (Fig. 54).

The Late Devonian era, in contrast to the Early Devonian, especially its first half (Frasnian age) was a time of widespread development of marine transgressions, a time of predominant dominance of the sea over the land. Similar eras in the life of the Earth are called thalassocratic.

Restoring the position of the Devonian climatic zones is difficult, since terrestrial vegetation is sparse. Only character traits A number of continental and lagoonal facies of the Devonian allow us to draw some paleoclimatic conclusions, which, however, are insufficient to restore the general picture of climatic zonation in the Devonian period.

When considering the conditions for the formation of the “ancient red sandstone,” many facts point to the arid climate of the intermountain depressions in which these sediments accumulated. Apparently, the middle part of the Russian Plate was characterized by a dry and hot climate in the Devonian, as evidenced by the widespread development of lagoonal chemogenic sediments (dolomite, gypsum, etc.) here. The same precipitation marks a zone of arid climate within Europe, stretching from northwest to southeast. From other evidence of the Devonian climate - the tillies of the Cape Mountains South Africa(thickness 30 m), length 500 km. It is unclear whether the moraine accumulations associated with this glaciation are of continental or mountain origin. No other manifestations of glacial activity in the Devonian are known.

The most characteristic Devonian facies is the "Old Red Sandstone" facies. (Old Red sandstone) widespread in all countries Northern Hemisphere(Fig. 54). It is assumed to be a continental sandy desert facies. However, finds of organic remains in red sandstone (shelled fishes, phyllopods) suggest that this facies is mixed

Rice. 54. Schematic map of the continent of ancient red sandstone and its bordering zone / - the main modern outcrops of ancient red sandstone; 2 - Hercynian massifs (marine Devonian); S-S- the northern border of marine transgressions onto the continent of ancient red sandstone; Yu-Yu- southern boundary of the distribution of ancient red sandstone layers in the marine Devonian Central Europe(Ginou, 1952)

lagoon-continental and lagoon-sea. In addition to "ancient red sandstone", lagoonal facies are often represented by the facies of closed brackish basins. They formed the oil-bearing facies of cypridine shales and the peculiar Domanik facies of the European part of Russia.

History of platform development