Let's take atlases and find a tectonic map of the world. The main signs of the tectonic map show the time of formation of mountain-folded areas (the final stage of the geosynclinal cycle of development), or the age of the foundation of the platform.

On the tectonic map, the first symbol (red color) shows the shields and foundations of ancient platforms of the Early Proterozoic age, formed during the Karelian tectonic cycle. The rocks in these territories were formed during the Archean and early Proterozoic.

The second character reflects the platforms and shields of the Baikal cycle (crimson), which were formed in the Late Proterozoic.

The third sign (gray-blue color of the territories) indicates the folded areas of the early Paleozoic and the foundations of young platforms that appeared in the early Paleozoic as a result of the Caledonian cycle of the earth's crust. These folded areas in subsequent eras turned into folded-faulty ones under the influence of splits of the epigeosynclinal and epiplatform orogenies.

The fourth sign (brown color) corresponds to the Hercynian development cycle of the Late Paleozoic, when new mountain-folded areas were formed, which then turned into folded-faulted areas, or into the foundations of young platforms.

The fifth sign (green color) indicates the Mesozoic era and the Cimmerian tectonic cycle, when the largest mountain-folded areas were formed. Only in some places the foundations of young platforms or fold-fault areas began to form.

The sixth sign reflects the fault and thrust areas of the Alpine cycle (orange color), the areas of island arcs of the same Cenozoic era are shown in yellow.

A number of additional signs are used on the map. An additional sign in the form of dots indicates the formation of a sedimentary cover of the platform. An additional red dash sign shows modern discontinuous motions, which manifest themselves in the form of earthquakes and form the structure of the discontinuous region.

In the Archean and early Proterozoic, the foundations of the following ancient platforms and shields were formed: the North American with the Canadian and Greenland shields, the East European with the Baltic and Ukrainian shields, the Siberian with the Anabar and Aldan shields, the African, South American, Hindustan, Chinese, Australian and Antarctic with a large group of shields.

Late Proterozoic structures: basements of the Brazilian, Arabian, Central Australian and northern West Siberian platforms; folded areas - Yenisei-Baikal, Timan-Pechora, Central China, North and East Greenland, Central and East African, North European.

Early Paleozoic structures: young platforms - Patagonian and East Australian, in the southern part West Siberian; folded areas - North Appalachian, British, Scandinavian, Svalbard, Altai-Sayan, Southeast Asia, Kazakhstan-North Tien Shan.

Structures of the late Paleozoic: young platforms - Mexican, Pyrenean, West European, Turan, in the western and eastern parts of the West Siberian, Mongolian; folded areas - South Appalachian, Northern Archipelago, Harz, Novaya Zemlya-Ural, Altai-Mongolian, South Tien Shan, Central Tibetan, Algerian, Cape, East Australian.

Mesozoic structures: folded and folded-rupture areas - Alaska-Cordillera, Kolyma-Chukotka, Arctic, Amur-Sikhote-Alin, North and South Tibet, Malacca-Indochina, Kalimantan Islands; underthrust-thrust Verkhoyansk region. The underthrust-thrust structure is determined on the continent at the boundaries of lithospheric plates by the presence of a foredeep (Predverkhoyansky) and a lowland parallel to the ridge of the mountainous thrust zone (Verkhoyansky anticlinorium, Fig. 55). In fold-fault areas, there is no large marginal foredeep-lowland parallel to the mountain range.

Cenozoic structures: fold-discontinuous areas - Rocky Mountains, Central American, Pyrenean, Apennine, Balkan, Asia Minor, Pamir, Iranian, Indochinese, Atlas, Kamchatka, Sakhalin, West Antarctic; underthrust-thrust areas - Aleutian, Kuril, Japanese, Philippine, New Guinean, New Zealand, Sunda, Zagros, Himalayan, Antilles, Andes.

Chapter III. TECTONICS

In tectonic terms, the studied area is located on the territory of a folded area.

According to the results of analyzes of the geological map, stratigraphic column, geological section, two structural stages can be distinguished: 1) D1-2bsk - C1sm; 2) I2 - K1sch.

As part of the first structural floor, two structural tiers can be distinguished. As part of the second floor, one structural tier with minor disagreements can be distinguished.

First floor.

lower structural layer.

The lower structural stage is composed mainly of volcanic rocks: volcanic breccias, tuffs, and other rocks of volcanic activity. From this we can conclude that during this period there was a maximum explosive stage of volcanic activity.

The rocks of this stage come to the surface in the northwestern, central, southwestern, and southeastern parts of the sheet. Separated in the volume of the Byskar series. The rocks of the lower tier are crumpled into sweetness.

The first fold is located in the southwest. The apparent width of the fold is about 1 km, and the length is 7 km. Stretching from west to east. The type of fold is anticlinal, according to the ratio of the axes - linear. The core includes rocks of the Byskar series. On the wings of the rocks of the middle and late Devonian system. The fold is asymmetric, because the angles of incidence are different on the wings.

The second fold is located in the central part of the sheet in the west. The rocks of the Byskar Series are also folded. The fold is approximately 1 km wide and 3 km long. The type of fold is anticlinal, according to the ratio of the axes - brachymorphic. The composition of the wings includes rocks of the middle and late Devonian system. The fold is asymmetric, because the angles of incidence are different on the wings.

The third fold is located in the northwestern part of the sheet in the west. The core of the fold contains rocks of the Byskar series. The apparent width of the fold is about 7 km, and the length is 13 km. The type of fold is anticlinal, according to the ratio of the axes - linear. On the wings are rocks of the middle and late Devonian system. The fold is asymmetric.

Upper structural layer.

The upper structural stage is composed of terrigenous-carbonate sediments. The stage was formed under continental conditions. The stage is represented in the volume of the Toltakovskaya, Saragashskaya, Beyskaya, Oidanovskaya, Kokhaiskaya, Tubinskaya, Bystryanskaya, Altai, Nadaltayskaya and Samokhvalskaya formations.

The deposits that make up this suite, mostly rocks, are exposed in the entire western part. There is volcanic activity in the Carboniferous period, which is represented by tuff sandstones. The rocks of this stage are crumpled into folds.

The fourth fold is located in the central western part of the leaf. The fold is anticlinal. The core contains rocks of the Toltakov Formation, which are brachymorphic in terms of the ratio of the axes. The fold is asymmetric and broken by a fault with a fault. The wings of the fold are rocks of the Middle Devonian system.

The fifth fold is located in the northern central part of the leaf. The fold is anticline, brachymorphic in relation to the axes. The core contains rocks of the Tol'takov Formation. On the wings are rocks of the middle and late Devonian system. The fold is asymmetric. The length of the fold is 1 km, the width is 1 km.

Second floor.

The structural stage is composed mainly of terrigenous sediments. This floor shows two small breaks in sedimentation in the eastern part. The deposits that make up this floor are distributed in the eastern part of the sheet. The rocks of this stage do not form folded structures.

Lithology and prediction of reservoirs in the Neogene deposits Taman Peninsula

The Anastasievsko-Troitskoye field is confined to the anticline fold of the same name, located in the central part of the West Kuban foredeep...

Measures to combat ARPD in production wells equipped with SHSU at the Stepanovskoye field

The Stepanovskoye deposit, confined to the uplift of the same name, is tectonically located on the Dubogorskaya terrace, which complicates the northern slope of the Bashkir dome...

Optimization of waterflooding regime at the Alibekmola field

In the regional tectonic plan, the Alibekmola deposit is confined to the uplift of the same name, located in the eastern marginal zone of the Caspian depression...

The tectonics of the area is determined by the position on the southwestern margin of the Donets Basin in the area where the basin meets the northern slopes of the Azov part of the Ukrainian crystalline massif...

Features of the structure and calculation of the reserves of the mine field in the South-Donbass coal-bearing region of the Donetsk basin

Several erosions are observed within the mine field, including erosion of the coal seam. The first gap runs from the mark +223 m to the mark +214. It begins under sediment and is replaced by siltstone and sandstone...

Features of power supply of a coal mine. Replacement of a tunneling machine in the conditions of the mine "Yerunakovskaya VIII"

In geological and structural terms, the area of the plots is located along the periphery of the southwestern part of the Yerunakovskaya brachysyncline and is part of a bowl-shaped monocline with the direction of the stratum dip to the east, northeast and north...

Feature evaluation geological structure site and occurrence of ore bodies

The Azial prospective area is located in the Ayan-Yuryakh anticlinorium of the Yano-Kolyma fold-thrust system. The anticlinorium is mainly made up of Permian deposits, less often in synclines there are rocks of Triassic age...

Evaluation of the ore body in the Derbinsk fluorite zone (Eastern Sayan)

Structurally, the area is located in the eastern part of the North Minusinsk depression in the zone of its junction with the folded structures of the Eastern Sayan ...

Calculation of reserves of the Odoptu-Sea field (Northern Dome)

In tectonic terms, the work area covers the structures of the North Sakhalin and Deryuginsky Cenozoic troughs (Fig. 2). The beginning of the formation of troughs is associated with the early Oligocene (Machigar time)...

Minerals of the North Caucasus

This area belongs to an area with a complex geological structure. The complex folded occurrence of rocks is disturbed by faults located in the southeastern part of this area ...

Construction of geological maps based on field descriptions of geological observation points

In tectonic terms, the study area is located on the territory of the Hercynian folded area. The central and NE parts are characterized by a more spacious structure, without the presence of folds or other tectonic forms...

Construction and analysis of geological maps

In the section, on the territory of the map, according to the nature of folding, saturation of igneous rocks and the presence of the degree of metamorphism, inherent angular and azimuthal unconformities, three structural stages are distinguished: Archean...

The use of horizontal wells for initial stage development of the Orenburg oil and gas condensate field

The Orenburg swell, with which the OOGCF is connected, has a rather complex structure due to the manifestation of tectonic and sedimentary structure-forming factors within its limits. Stretching from west to east...

The use of chemical reagents for the prevention and control of hydrates in gas production

The Yamburg gas condensate field is associated with the Yamburg-Kharvutinsky group of uplifts...

Trial operation of an oil deposit at the North Nuraly field

Based on the results of prospecting seismic surveys of the CDP in 1985-1989. the monoclinal-block structure of Northern Nuraly was revealed. The Northern Nuraly deposit is located in the northwestern part of the Akshabulak graben-syncline...

Ministry of Education of the Republic of Belarus

educational institution

"Gomel State University

named after Francysk Skaryna"

Faculty of Geology and Geography

Department of Geology and Exploration of Mineral Resources

TECTONIC ANALYSIS OF GEOLOGICAL MAP #2

(explanatory note)

Executor:

student of group 1- РВ-31 _______________

Senior Lecturer _______________

Gomel 2010

Introduction

The purpose of this laboratory work is to consolidate knowledge in the course "Geotectonics", and also learn how to independently perform a tectonic analysis of a geological map. Tectonic analysis consists mainly in drawing up a tectonic scheme and writing an explanatory note to it, highlighting the main tectonic structures, their morphology and geological history of development.

To write an explanatory note, the following source materials were given: geological map No. 2 with symbols, a stratigraphic column and a geological section, as well as a workshop on geotectonics "Tectonic analysis of geological maps".

The objectives of this work are: the definition of the main structural elements of the earth's crust, the definition of structural floors, the classification of folded and discontinuous faults.

1 GEOSTRUCTURES

This territory belongs to the ancient platform (craton). This is indicated by the thickness of the main stratigraphic units in the sedimentary cover tens of meters; absence of disjunctive disturbances and igneous formations; horizontal and subhorizontal occurrence of layers that make up the sedimentary cover. The study area has a two-tier structure: a crystalline basement (of Mesozoic and Cenozoic age) and a sedimentary cover overlying it.

2 STRUCTURAL FLOOR

The area under study is an area, the formation of which took place in different epochs of tectogenesis: Hercynian, Cimmerian and Alpine.

The cover complex of the study area represents the deposits of the Cenozoic erathem, represented by the Neogene system, the Mesozoic erathem, which is composed of rocks of the Jurassic and Cretaceous systems, as well as the Paleozoic erathem, the rocks of which are composed of Devonian deposits. Within the study area, three structural floors are distinguished: lower, middle and upper.

Lower structural floor

This structural stage is characterized by a horizontal occurrence of layers. This structural floor is located in the central part of the study area. The formation of this floor took place in the Caledonian era of tectogenesis. Sedimentation took place in coastal-marine conditions, accompanied by either regression or transgression of the sea. The rate of precipitation accumulation is low.

Middle structural floor

This structural floor extends from east to southwest. It belongs to the Mesozoic erathem, which refers to the Hercynian era of tectogenesis. Sedimentation took place under marine conditions. The rate of accumulation of deposits is low.

Upper structural floor

The upper structural floor is located in the southeast of the study area. This floor belongs to the Cenozoic erathem, which belongs to the Alpine era of tectogenesis. Sedimentation took place in coastal-marine conditions. The rate of accumulation of precipitation is low.

3 FORMATIONS

In the study area, rocks of the Paleozoic, Mesozoic and Cenozoic erathems are distinguished, represented by deposits of the Devonian, Jurassic, Cretaceous, and Neogene systems. The development of the earth's crust here took place during the plate stage, on the basis of which the following formations can be distinguished: marine terrigenous transgressive, carbonate and marine terrigenous regressive formations.

Marine terrigenous regressive and transgressive formations.

Their characteristic feature is the regressive and transgressive sequences, that is, up the section, relatively deep-water deposits (marls, clays) are replaced by shallow-water ones (sands, pebbles) and, conversely, shallow-water deposits are replaced by deep-water ones. All these sequences are observed throughout the geological history of the study area. The thickness of the formations is a few tens of meters.

carbonate formation

The deposits of this formation are stratigraphically confined to the deposits of the Frasnian and Famennian stages of the Devonian system. These deposits are represented by limestones and marls rhythmically interbedded with sandstones, siltstones and mudstones. The power is the first tens of meters. characteristic feature of this formation is that the section is dominated or completely composed of carbonate rocks (limestones). The deposits are confined to the plate stage of the development of the earth's crust, which were formed and accumulated under shelf conditions.

4 SMALL PLICATIVE AND DISJUNCTIVE STRUCTURES

Small plicative and disjunctive structures are not observed in this territory. The layers are horizontal. There is only the roof of the Zakonsky horizon, in which the stratoisohypses of the roof increase from north to south.

4 HISTORY OF TECTONIC DEVELOPMENT

The area under study is an area whose formation took place in different epochs of tectogenesis.

The rocks of the Paleozoic, Mesozoic and Cenozoic systems are involved in the geological structure of the study area.

The rocks of the Paleozoic erathema are represented by deposits of the Devonian system. The Devonian were transformed in the Hercynian epoch of tectogenesis.

The rocks of the Devonian system are located in the central and north-west of the region in the form of small rock outcrops. In the Devonian, the Hercynian epoch of tectogenesis took place, but this was not reflected in any way in this territory, at that time there was a normal accumulation of sediments without crushing and uplifts. The Devonian rocks accumulated in the sea. During this period, tectonic movements are expressed in the form of slow ups and downs of the terrain, leading to transgression and regression of the sea.

Jurassic deposits are located in the northwestern part of the study area. The Jurassic deposits were transformed during the Cimmerian epoch of tectogenesis. There is a stratigraphic unconformity with the Lower Cretaceous rocks. There is also a sedimentation hiatus in the Lower and Middle Jurassic, which indicates a retreat i.e. regression of the sea, and then a sharp decrease in the Upper Jurassic.

The Cretaceous system is represented by two divisions, upper and lower. The deposits of this system are located in the northwest of the study area. Changes in the Cretaceous deposits occurred during the Cimmerian and Alpine eras of tectogenesis. At this time, a stable slow uplift of the territory continues, i.e. sea retreat.

The Neogene system is represented by the Pliocene. Changes in these rocks occurred during the Alpine era of tectogenesis. In the Lower Neogene (Miocene) there is a gradual regression of the sea, which indicates the uplift of the territory, which led to a stop in sedimentation, which is evidenced by the absence of deposits of this period. In the Pliocene, a gradual transgression of the sea occurs, which indicates a slow subsidence.

CONCLUSION

As a result of the work done, an explanatory note for the geological map No. 2 was compiled, and a tectonic scheme of the area was drawn up.

In the process of work, knowledge of geotectonics, historical geology, lithology was used. The descriptions are made in accordance with the methodological requirements.

Send your good work in the knowledge base is simple. Use the form below

Students, graduate students, young scientists who use the knowledge base in their studies and work will be very grateful to you.

Posted on http:// www. all best. en/

Course work

in structural geology

Analysis of the geological map and map of the tectonic structure

Introduction

The course project sums up the study of the most important part of the course of structural geology, devoted to the forms of occurrence of rocks and methods of their representation on geological and tectonic maps and sections. It contributes to the development of the ability to freely read geological maps and use the collected material for a comprehensive theoretical analysis.

The main goal of the course work is to consolidate knowledge of structural geology and develop the acquired skills in analyzing a geological map and a map of a tectonic structure. The work also aims to teach how to use geological map data for a number of generalizations.

To analyze geological maps, it is necessary to be able to determine the age sequence of sedimentary, metamorphic and igneous rocks and establish the forms of their occurrence; identify and determine the types of unconformity surfaces, analyze their significance for the geological history of a given territory; identify the most characteristic rock formations and analyze their relationship with the tectonic structure and geological history; taking into account the age, composition and thickness of the identified stratigraphic units and their changes along strike, as well as on the basis of an analysis of the tectonic structure, establish the main structural elements of the area and give its tectonic zoning; be able to determine the age of igneous formations, as well as to establish to which tectonic epoch the igneous complexes of the study area belong; be able to describe the tectonic structure and outline the main stages of its formation; analyze the geological history of the area and draw the main conclusions about the patterns and relationships of the most important geological events, drawing on the knowledge gained from the courses of historical and structural geology.

When solving the questions posed, a number of methods are used: analysis of geological boundaries on the map, historical-geological and paleotectonic methods, analysis of the sequence of bedding, analysis of breaks and unconformities, method of studying facies, method of studying thicknesses, formational analysis and other methods.

When performing this course work, the northern part of the educational geological map No. 23, scale 1: 50000, 1984, was used.

1. Relief and river network

1.1 Relief

Two types of relief are distinguished in the studied territory - mid-mountain and low-mountain. The lowest elevations are 640 m, the highest are 1400 m. The maximum elevation is 760 m.

Low-mountain relief prevails, it occupies about 65 - 70% of the area of the region. The maximum elevation here is 360 m.

Alpine relief occupies 30-35% of the area of the entire territory, the maximum elevation is 400 m.

The relief is confined to outcrops of Neogene, Paleogene, Cretaceous and Jura rocks.

1.2 River network

The entire studied territory is occupied by the basin of the Belaya River, formed by two large tributaries that merge in the southwest of the region. The river is represented by the main channel and many tributaries. The direction of the river flow is to the northeast, the channel is slightly meandering.

The left tributaries have a flow direction to the south, the right - mainly to the north.

Of the large tributaries, one can also note the mountain stream Plishka and the Mutny stream, located in the eastern and northeastern parts of the region.

River floodplain width Belaya varies from 1 km to 100 m, and the floodplain area increases in the direction of the current, i.e. to the northeast. The floodplain in the Mutnoy creek valley is up to 1.5 km wide. The height of the terraces is up to 40 m. The floodplain and terraces are composed of alluvial pebbles and sands

1.3 Stratigraphy

The study area includes rocks of the Jurassic, Cretaceous, Paleogene and Neogene systems. The Jurassic, Cretaceous and Paleogene systems are composed of sedimentary strata, the Neogene system is represented by volcanic-sedimentary rocks.

Jurassic system.

The deposits of the Jurassic system are distributed over a small area in the western and northwestern parts of the study area.

Deposits of the Middle and Upper Jurassic are known.

Middle department.

The rocks of the middle section of the Jurassic system were distributed only in the so-called tectonic wedges formed by large faults and located in the north-west of the territory.

The sequence is composed of red clays with the presence of limestone marls, has a thickness of more than 270 m.

Upper department.

Represented by deposits of the Tithonian stage.

Tithonian stage.

Deposits of the Tithonian stage of the Upper Jurassic are known within tectonic wedges, are more widespread than the rocks of the Middle Jurassic and are represented by red limestones. On the underlying rocks, the deposits of the Tithonian stage occur according to. The thickness of the entire thickness is 300 m.

Chalk system.

In the study area, the Cretaceous system is represented by two divisions - upper and lower. The deposits of this system are distributed in the northwest and southwest of the territory.

Lower section.

Represented by the Polyana Formation.

Polyanskaya suite.

The deposits of the Polyanskaya suite are not widely distributed, they are observed only in the north-west of the territory, mainly in the area locality Yurievka and are represented by sandstones. The thickness of the thickness is more than 600 m.

The sequence rests on the underlying rocks unconformably; contact with the underlying Jurassic rocks is traced along a deep fault.

Upper department.

Represented by the Lyut retinue.

Lyut Formation

The deposits of the Lyutskaya suite stretch from the northwest to the southeast of the territory, crossing the river. Belaya near the settlement Yuryevka; a small outcrop of rocks is also observed in the southwest.

The sequence is composed of sandstones and rhythmically alternating marls and clays, its thickness is 280 m. On the underlying rocks of the Polyana suite, the Upper Cretaceous rocks occur in accordance with the Jurassic deposits, the contact is traced along the fault.

Paleogene system.

In the study area, the Paleogene system is represented by all three divisions. The rocks of this system are quite widespread; they are observed in the west and south-west of the region.

Lower section.

The deposits of the Lower Paleogene are most widely developed and are known mainly in the southwest of the territory. They are represented by rhythmically alternating siltstones and blue, red and green clays. The thickness of the entire stratum is 320 m.

Middle and upper divisions.

The undivided middle and upper sections are represented by the Lumshor Formation. The upper section is represented by the Petrovsky Formation.

Lumshor suite.

The deposits of the Lumshor Formation are quite widespread and stretch from west to south of the territory. They are represented by a rhythmic alternation of siltstones, mudstones and marls. The thickness of the sequence is 500 m. The contact with the underlying deposits of the Lower Paleogene is consistent.

Petrovsky retinue.

The deposits of the Petrovsky Formation stretch from the west to the south of the territory and are represented by black siliceous marls, mudstones and limestones. The thickness of the layer is 440 m.

Neogene system.

The Neogene system is represented by two divisions - the lower, Miocene, and the upper, Pliocene. Neogene deposits are widespread in the area and are represented by both sedimentary and volcanic-sedimentary rocks.

It is composed of strata of sedimentary rocks distributed in the north, east and southeast of the territory. There are three formations: Dusinskaya, Chernikskaya and Mikhailovskaya.

Dusinsky retinue.

The deposits of the Dusinskaya suite are not widely distributed and stretch along the southern margin of the Miocene deposits from the northwest to the southeast. Detrital rocks - conglomerates, gravelstones and sandstones, with a total thickness of more than 520 m. Contact with the underlying Mesozoic and Paleogene deposits can be traced along a large deep fault.

Chernik suite.

The deposits of the Chernikskaya suite are the most widely developed of all Miocene rocks. They occupy the entire area in the north, east and southeast of the district. Represented by gravelstones, sandstones and clays with interlayers of brown coals. The thickness of the entire stratum is 480 m.

Mikhailovskaya retinue.

The rocks of the Mikhailovskaya Formation are known in the northwest, northeast, and east of the study area. They are represented by conglomerates, sandstones and clays with interlayers of liparitic tuffs with a total thickness of 400 m. The contact with the underlying deposits of the Chernikskaya suite is consistent.

The upper section of the Neogene system is represented in the studied area by volcanic-sedimentary rocks. There are three subdivisions: lower, middle and upper. The lower and middle sections are undivided and are represented by deposits of the Bystrinskaya suite.

Bystrinsky suite.

Deposits of the Bysrinskaya suite are known mainly in the central part of the region. They are represented by a sequence of liparitic ignimbrites with a thickness of more than 700 m, lying with angular unconformity in the Miocene and Mesozoic deposits.

Middle Pliocene. ,

In the Middle Pliocene, sequences of dacitic lavas are known, distributed in small areas in the east and northeast of the territory and having a thickness of 85 m. Andesitic lavas are also known, common in the central and eastern parts of the region. Facies replacements by tuffs and tuff breccias occur in their thickness. The thickness of the strata is 250 m. The nature of the relationship with each other and with the underlying ones is an angular unconformity.

Upper Pliocene.

Deposits of the upper subdivision of the Pliocene are distributed in the east of the territory and stretch from south to north. They are represented by andesite-basalt lavas, the thickness of which is 80 m.

2. Intrusive formations

2.1 Pliocene intrusive formations

Intrusive formations are not widely developed in the study area and are represented by a single intrusive body located in the west of the territory. Its area is 0.75 km2, in plan it has a narrow, 250 m wide, elongated shape. Composed of granite-porphyry.

The size of the intrusive body is small; According to the structural features, it can be attributed to dikes.

The dike is dated to the Pliocene and has a secant contact with the Upper Cretaceous deposits, with the Upper Jurassic - contact along the fault. (Fig.1)

Rice. 1 Pliocene dyke composed of granite-porphyries

Vortex formations.

The rocks of the vent facies in the study area are represented by Middle Pliocene and Lower-Middle Pliocene formations, confined mainly to a large fault.

Vent formations of the Lower-Middle Pliocene.

Known in the south of the territory, in the area of the sources of the stream. Plishka. In total, there are 4 bodies in the area. In plan they have an elongated oval shape, their area is from 1 km2 to 0.7 km2. Composed of liparitic ignibrites, they belong to necks according to their structure.

They cut through the Pliocene deposits of the Bysrinskaya suite and are overlain by the Middle Pliocene strata.

Rice. 2 Vent formations of the Lower-Middle Pliocene.

Vent formations of the Middle Pliocene

4 bodies are known in the north-west of the territory, in the area south of the settlement of Yuryevka and in the north-east of the territory. They have an elongated oval shape.

The area of the smaller of them is 0.3 km2, the rest is about 0.75 km2. They are composed of dacites and, according to the features of their structure, belong to the necks. The bodies located in the center of the area break through the Mesozoic deposits and deposits of the Bysrinskaya suite. One of the bodies is overlain by andesite-basalts of the Middle Pliocene.

Rice. 3 Middle Pliocene vent formations

Rice. 4 Middle Pliocene vent formations

Tectonics.

According to the conditions of occurrence and magmatism in the structure of the region, the middle Alpine geosynclinal and late Alpine orogenic structural stages are distinguished.

Middle Alpine geosynclinal structural stage.

Includes deposits from the Middle Jurassic to the Petrovsky Formation of the Upper Paleogene, crumpled into linear folds. Developed in the southwest of the region.

In the structure of this structural stage, the following formations are distinguished: carbonate-terrigenous, including deposits of the Middle Jurassic (red clays, marls and limestones); formation of red limestones of the Tithonian stage of the Upper Jurassic; the formation of uneven-grained sandstones of the Polyanskaya suite of the Lower Cretaceous; two flysch carbonate-terrigenous formations, the lower of which includes deposits of the Lower Cretaceous Lyutskaya suite, and the upper one - the Petrovsky and Lumshorskaya formations of the Middle and Upper Paleogene (here, members of itmically alternating marls, siltstone clays, mudstones and limestones); flysch terrigenous formation of Lower Paleogene rocks (colorful clays and siltstones).

The rocks that make up the Middle Alpine geosynclinal stage are crumpled into linear folds. The axes of the folds stretch from the west and northwest to the south, crossing the river. Belaya in the area of the settlement Yuryevka and upstream.

According to the shape of the lock, the folds are rounded and comb-shaped, and the locks of the folds of older rocks (Cretaceous) have a comb-like shape. With respect to the axial surface to the horizon, the folds are inclined. The angles of inclination of the wings of the folds from to.

Among the clearly visible folds of the first order, 2 anticlinal and 1 synclinal folds stand out.

Synclinal folds.

The fold is located at the confluence of two tributaries in the Belaya River (Fig. 5), has a length of more than 7 km and a width of more than 2 km.

The wings of the fold are composed of rhythmically alternating carbonate-terrigenous rocks of the Lower and Middle Paleogene, in the core of the fold there is a flysch sequence composed of rhythmically alternating rocks of the Upper Paleogene Petrovsky Formation.

The axis of the fold stretches from west to south. The angles of inclination of the wings, and on the northern wing (the angles change accordingly from west to south) and on the southern wing.

The fold is round in shape of the castle, the hinge plunges in the southeast direction, rises in the northwest, forming a centriclinal closure.

Rice. 5 Synclinal fold

2.2 Anticlinal folds

One of them is located in the northwestern part of the territory, its axis stretches from the northwest to the south and, making a smooth bend, crosses the river. Belaya near the village of Yuryevka. The fold is over 10 km long and slightly over 1 km wide. Its wings are composed of rhythmically alternating carbonate and terrigenous rocks of the Upper Cretaceous Liutskaya suite, in the core - inequigranular sandstones of the Lower Cretaceous Polyanskaya suite.

The northern flank of the fold has a slope, the southern one.

The lock of the fold is ridge-shaped, the hinge either plunges in the direction to the northwest and southeast, forming two periclinal closures, then it rises. (Fig. 6)

Rice. 6 Cretaceous anticlinal fold

The second anticline fold is located in the southwest of the region. It is over 5 km long and up to 1 km wide.

The wings are composed of flysch Middle and Upper Paleogene sequences, in the core there is a rhythmic alternation of clays and siltstones of the Lower Paleogene age. The angles of inclination of the wings: at the southern wing, and at the northern one (the angles change in the northwest direction).

The lock of the fold is rounded; on immersion, the hinge forms a pereklinal closure. (Fig. 7)

Rice. 7 Anticlinal fold composed of Paleogene deposits

Among the folds of the second order, 3 synclinal folds can be distinguished, two of which are confined to the Cretaceous anticline fold, and one - to the Paleogene anticline fold.

There are two anticlinal folds of the second order - one is confined to the Cretaceous anticline fold of the first order, the second - to the Cretaceous deposits, the outcrop of which is observed in the south-west of the region.

2.3 Late Alpine orogenic structural stage

Includes deposits of the Miocene and Pliocene. According to the conditions of formation and features of the structure, it is divided into two sub-levels - upper and lower.

Lower structural subfloor.

Includes Miocene deposits folded into brachyform folds. Developed in the north and northeast of the region.

In the structure of the substage, the following formations are distinguished: the lower molasse, composed of conglomerates, gravelstones and sandstones of the Dusinsky suite of the Miocene; coal-bearing molasse, including deposits of the Chernikskaya suite and the upper molasse, including rocks of the Mikhailovskaya suite.

Tectonic structure of the region:

The rocks of this substage are crumpled into brachyform folds.

The limbs of the synclinal folds are composed of coarse clastic rocks of the Chernik and Dusinsk suites of the Miocene, with rocks of the Mikhailovskaya suite in the core.

The castle is round, the angles of inclination are gentle, from to, and largest angles were noted near the southern flank of the fold, composed of rocks of the Dusa Formation.

Upper structural subfloor.

Includes Pliocene deposits that make up a large volcanic edifice.

Liparitic ignimbrites of the Bysrinskaya Formation of the Lower-Middle Pliocene and dacitic lavas of the Middle Pliocene compose the terrestrial porphyry formation. Andesite-basaltic lavas, tuffs and tuff breccias of the Middle and Upper Pliocene make up the andesitic formation.

Tectonic structure of the region:

The volcanic edifice has a synclinal structure.

Lines of primary banding are directed towards the center at gentle angles no more.

Lower-Middle Pliocene deposits of the Bysrinskaya suite (liparitic ignimbrites) are confined to the intrusion of vent formations of the Lower-Middle Pliocene and form covers. They are distributed over a large area in the center of the region and cover all Mesozoic and Miocene deposits.

Dacitic lavas of the middle Pliocene compose two small shield volcanoes - one in the northwest of the territory, the other in the northeast. It is characterized by horizontal and inclined (up to) lines of primary banding.

Andesitic lavas of the middle Pliocene form flows with horizontal and inclined (up to) flow lines.

In smaller areas, andesite-basaltic lavas of the Upper Pliocene are common. They have sloping streamlines and stretch from south to north.

Breakdown violations.

On the territory of the study area, there are discontinuous faults of various types and age.

It is possible to distinguish inclined and vertical faults.

All inclined faults are confined to zones of linear folding. They have a longitudinal strike, a large extent, the angle of inclination of the displacer is about, the displacer itself has an inclination to the northwest.

Faults and reverse faults stand out among the faults.

Near reverse faults, the northwestern block is uplifted and composed of older rocks; near normal faults, the northwestern block is lowered, it is composed of younger rocks.

The time of formation of oblique faults is after the accumulation of the Upper Paleogene Petrovsky Formation, after linear folding, before the accumulation of the Miocene.

A large vertical normal fault stretches across the entire territory of the region from the northwest to the southeast, separating the orogenic and geosynclinal structural levels, and overlaps in the southern and central parts Pliocene volcanogenic-sedimentary formations. The northeastern block, composed of Miocene rocks, is subsided, while the southwestern block, composed of Jurassic, Cretaceous, and Paleogene deposits, is uplifted. Vertical normal faults are attached to this large fault in places, forming wedges along which Jurassic deposits are raised.

The age of the fault is after the accumulation of the Petrovsky Formation of the Late Paleogene, after linear folding, before the accumulation of Miocene strata. The fault is long-lived and remained tectonically active during the accumulation of Miocene deposits.

The latest faults are confined to the effusive strata of the Pliocene. They are located along the banks of the stream. Plishka, and are represented by vertical faults that form graben-like structures in pairs.

sedimentary mountainous tectonic geological

3. History of the geological development of the area

A geosynclinal trough existed on the territory of the studied area in the Middle Jurassic.

The sediments formed during this period testify to the existence of a marine basin of moderate depth with a remote coastline in this area, as evidenced by the terrigenous material present in the sequence.

In the Late Jurassic, the area of the sea basin increased, the coastline moved further away from the coast, as evidenced by the absence of terrigenous material in the thick limestone member. After that, there was an uplift and the associated regression of the sea.

In the early Cretaceous, the transgression of the sea began. The sea basin was shallow with a close coastline, as evidenced by a thick sequence of inequigranular sandstones formed due to the removal of clastic material from the nearby land.

Further, in the Late Cretaceous, the basin continues to deepen, and throughout both the Late Cretaceous and the entire Paleogene, carbonate and terrigenous rocks are deposited here, the rhythmic alternation of which indicates the possible action of turbidity flows.

After the accumulation of the Petrovsky Formation of the Late Paleogene, the region was uplifted and the sea regressed, after which the accumulated sediments were crushed into linear folds and faults were formed longitudinal and transverse to these folds. The Middle Alpine geosynclinal structural stage was formed. During the subsequent time, this territory remained dry land.

In the north-eastern territory of the region in the Miocene there was a shallow marine basin. The close location of the land led to the accumulation of coarse clastic material here, which formed molasse formations, interlayers of coal formed here in the Chernik time, which indicates an extremely close location of the land, and during the accumulation of the Mikhailovskaya Formation there was a small supply of volcanic material, which probably occurred as a result of the activity of the volcano located outside the study area.

After the accumulation of the Mikhailovskaya Formation, an uplift occurred, as a result of this, the sea regressed, and the accumulated sediments were crushed into brachiform sweets. The lower substage of the orogenic Late Alpine structural stage was formed.

In the Pliocene, deep-seated processes sharply intensified, which led to the intrusion of Pliocene intrusions along large faults, with which the formation of tectonic wedges is associated, and, after that, to the beginning of the development of active volcanic activity, which continued throughout the Pliocene.

First, in the Lower and Middle Pliocene, magma was emplaced along a large fault, which formed vent formations, and the associated flows of liparitic ignimbrites were erupted.

In the Middle Pliocene, the intrusion of magma continued; vent formations and covers composed of dacitic lavas were associated with them.

Later intrusions of magma are associated with flows of andesites and andesite-basalts of the Middle and Upper Pliocene.

The tectonic activity of the region did not end there, several faults were formed, which formed graben-like structures.

Conclusion

The result of the analysis of the geological map was the writing of this term paper. A tectonic scheme and a diagram of the relief and river network were drawn up; sections, a block diagram and a structural-formational column were built.

In conclusion, it is worth mentioning the importance of doing this work, which consolidates all the material received over the previous two semesters.

Among the shortcomings, it should be noted that the deadlines for its implementation are too long. Perhaps they should be reduced to 1.5 months and set clear deadlines, which, of course, will only become an additional incentive for writing a course project as soon as possible.

List of used literature

1. A.E. Mikhailov. Structural Geology and Geological Mapping 2012.

2. Uspensky E.P., edited by Mikhailov A.E. Guidelines for term paper in Structural Geology and Geological Mapping 2009.

3. Benefit to laboratory work in Structural Geology, Geomapping and Remote Sensing 2010.

Hosted on Allbest.ru

Analysis of the tectonic map of the world. Reading a tectonic map and analyzing structures on the continents. The structure of the earth's crust

Chapter III. TECTONICS

Send your good work in the knowledge base is simple. Use the form below

Similar Documents

The estate of the ant-apostles on the old Basmannaya

Voronya Slobidka on Bolshaya Pirogovskaya Street Bolshaya Pirogovskaya House 51 stories

Maiden's Field Drive Hard Times

Tverskaya Zastava Square

Komsomol radial station

Analysis of the tectonic map of the world. Reading a tectonic map and analyzing structures on the continents. The structure of the earth's crust

Chapter III. TECTONICS

Send your good work in the knowledge base is simple. Use the form below

Similar Documents

Similar articles