Category: Geography Notes PPT

Holocene Epoch is a geologic time scale (shorter than period but longer than age) which has been the most recent one. It began 11,650 years ago after the last glacial period and is still continuing. The holocene is the youngest of the two Epochs, the other one being Pleistocene Epoch, that are classified under the Quaternary Period. Some of the geologists also consider the current Holocene Epoch as an interglacial period within the Pleistocene Epoch. But the most unique feature is that the Holocene time coincides with the late and post-Stone age history of the human kind. 

Different Classifications of Geographical Time Scale

The geological time scale is the classification system of the dating of chronology of the geological strata of the Earth over time. This classification system is used by the Earth scientists, geologists, and paleontologists to describe the time and any relationship that exists between the distinct events occurring in geologic history. The time scale and the classifications are done based on physical rock structures or rock layers, and the relationships along with the time when different organisms appeared, evolved and became extinct via the study of the fossilized remains and the imprints. The classification of the geological time scale is done into the following: Eons, Eras, Periods, Epochs and Ages. In this timeline classification, Eons are divided into Eras, Eras are further divided into Periods, Periods divided into Epochs and the Epochs are further subdivided into Ages. Thus, Holocene is an Epoch classified under the Quaternary Period, which comes under the Cenozoic Era, which is classified under the Phanerozoic Eon.

Under the classification of the Quaternary Period, comes the Pleistocene Epoch and Holocene Epoch. The Holocene is the Epoch which follows the Plestocene Epoch. It is also identified as a warm period and an interglacial period by the geologists, and Earth scientists. The striking feature of the Holocene time scale is the rapid proliferation, growth, and the impacts of Human species. The Holocene is characterized by all of the written history, technological advancements, development of many civilizations, and the current transition towards urbanization of the human population. The influence of humans is predominant in this Epoch and the impact on modern-era Earth and the ecosystems have led to the classification of the Holocene. 

The Holocene Time-scale

The word Holocene finds its origin in the Ancient Greek language. Holocene meaning, according to Ancient Greek, is “whole new”. Breaking the word of Holocene into the Greek roots helps in identifying the holocene meaning. The term ‘Holo-’ is derived from the word Holos which means “whole”. The other ‘-cene’ is derived from the word kainos which means “new”.Thus, when combined together, the holocene meaning is “whole new”. The reasoning behind this, is the consideration that this epoch is entirely new as it is the most recent one and is still continuing. Also, the suffix ‘-cene’ is used for all the seven epochs that are classified under the Cenozoic Era. 

According to the International Commision on Stratigraphy, the Holocene started 11,650 calibrated years ago before present. The Holocene Epoch is further sub-divided into five time intervals based on climatic fluctuations, which are also known as the Chronozones:

1. Preboreal: This is the time period between 10 kiloannum (ka) years – 9 ka before present (BP) (present i.e. 195)). 

2. Boreal: This lies between 9 ka – 8 ka years BP

3. Atlantic: 8 ka to 5 ka years BP

4. Subboreal: 5 ka – 2.5 ka years BP

5. Subatlantic: 2.5 ka years BP.

During the time of the Holocene, there have been many changes that have taken place in terms of geology and climate which have shaped the current world. Also, the changes occurring due to Global warming in the last century itself has also impacted the natural progression of this Epoch. We will understand a few of these changes as we go through with the article.

Geological Changes During Holocene

The movements of the continent under the pressure of tectonic forces, has been less than a kilometre in the span of 10,000 years of Holocene. Another important change in the geology of the Earth, during this Epoch has been the rise in the sea-level. In the early part of the Holocene Epoch, because of the melting of ice, the sea-level rises about 35 m. In the later part of the Epoch also, the sea-level rises by another 30 m. Many of the areas of landmass above around 40 degrees North latitude that had been covered by ice of the Pleistocene Epoch were depressed by the weight of Ice. Hence, as the glacial period began to recede and the ice began to melt, the landmass rose by180 meters during the late Pleistocene and early Holocene Epoch. These landmasses still continue to rise. 

Climate Changes During Holocene

As such the climate changes have been stable over the Holocene when compared to the cold period of Glaciation. The records collected from the ice cores have shown that before the start of Holocene there was a time period of warming happening globally which began after the end of the last of the ice ages and the cooling periods. The climatic changes became more and more regional and during the transition from the late glacial to Holocene the cold reversal known as Huelmo-Mascardi, began from South America in the Southern Hemisphere and most of the warmth flowed from south to north about 11,000 to 7,000 years ago. It is thought that this happened because of the residual glacial ice which was left in the Northern Hemisphere.

Early Human Settlements During Holocene

The Mesolithic age began with the beginning of the Holocene in most of Europe. In the regions of Middle East and Anatolia a very early neolithisation and Epipaleolithic period began. During this period the cultures that began include Hamburgian, Federmesser and Natufian culture. Also, some of the oldest inhabited places that are still existing such as the Tell es-Sultan (Jericho) in the Middle East began to be first settled. Other evidence of such settlements are given by archaeology at locations of Göbekli Tepe where proto-religion first began as long as 9th millennium BCE. Since then human courses have taken the known developments and continue till date.

It is noteworthy that, using terms like Holocene period, Holocene era or Holocene age, can be confusing as the terms period, era and age have different and definite meaning under the Geographical Time Scale classification system Hence, using Holocene or Holocene Epoch is more reliable and justifiable under such circumstances. 

Fossils are the remains of ancient living things like plants and animals preserved from the prehistoric period by the prospect of natural conditions. It is generally a rock in which organisms are preserved. It is found in sedimentary rocks, asphalt deposits, coal, amber and other materials. The study of fossils is called palaeontology. The bones, shells, leaves and feathers become fossils. It can be large or small accordingly. 

 

Index fossils are the fossils that are commonly found as well as widely distributed and are the fossils limited in the period. These are helpful in the determination of the age of organic rocks as well as other fossil assemblages. Not only this, but it also helps in establishing the relationships between the rock units and is also called guide fossils or indicator fossils. In this article, we will cover index fossils, index fossil definition & meaning along with index fossil examples and other related aspects which will be helpful to grasp this concept.

 

They can be defined as the fossil of plants and animals preserved in the rocks present in the earth which can be studied to know about the geological time span that has occurred over time. It is useful in being distinct and easily recognisable. It is also present abundantly and has a wide range of distribution on the planet and a short-range. They are quite useful in defining boundaries in the geological time scale and also for the strata’s correlation. In the strata of the marine environment, the index fossil fuels used are the family of Protists that have a hard body covering and large forms called ammonoids. Similarly, in the terrestrial strata environment, it is of Cenozoic Era which started 65.5 million years ago and mammals have been used widely as date deposits. They also have hard body parts which are bones, teeth, shells and thus, evolved rapidly.

 

Meaning of Index Fossil

These are those fossils that are useful for dating as well as correlating the different strata where it’s found. Some species lived in a particular space and environment and animal/plant life is preserved in rocks of the Earth that are a feature of a particular reach of geologic time or environment. These fossils are also known as guide fossils and indicator fossils which means those fossils which are used to define as well as signify geological stages. They are used by geological scientists. They are important aids to determine the correlation as well as the age of rock patterns. Geologists use large fossils to microscopic fossils to identify geologic time.

 

They use both large fossils/macrofossils as well as microscopic fossils or microfossils as indices to define as well as identify geologic periods.

 

If we talk about macrofossils, they have the advantage over the microfossils because they are easy to see and find in the field but actually, they are rare whereas the microfossils are used by mineral resources industries after extraction of required information from these fossils.

 

Index Fossil Definition

Few definitions of index fossils are mentioned below:

• “It is a fossil usually with a narrow time range and wide spatial distribution that is used in the identification of related geologic formations.” – Merriam-Webster

• “It is a fossil that is found in many places and comes from the same time in history so that scientists can use it to decide how old certain rocks are.” – Cambridge Dictionary.

• ” It is a widely distributed fossil, of the narrow range in time, regarded as characteristic of a given geological formation, used especially in determining the age of related formations.” ( Geology, Paleontology ) – Dictionary 

• ” Those fossils of the organisms that are helpful in identifying the geological time of the rocks or layers of rocks in which they were found. ” – General Definition.

 

Types of Index Fossils

There are some types of index fossils which include Ammonites, Brachiopods, Graptolites, Nanofossils and Trilobites. 

• Ammonites: The fossil of ancient marine animals is said to be known as an ammonite index fossil. During the Mesozoic era, they were common (245 to 65 million years ago ). After the Cretaceous period, they were not found as they went extinct during the K-T extinction ( 65 million years ago ).

• Brachiopods: They emerged 550 million years ago. It was first founded in the Cambrian age.  These are mollusc-like marine animals) that appeared during the Cambrian (540 to 500 mya) some of them still survive. They are said to be the most common fossils.

• Graptolites: They are thin and shiny. The markings on rock surfaces look like pencil marks. The name Graptolites comes from the Greek for “writing in the rocks.” These are widespread colonial marine hemichordates. They lived during the period of Cambrian roughly from  540 to 505 million years ago) to the early to mid-Carboniferous (360 to 320 million years ago). It is found in shales and mudrocks. 

• Nanofossils: These are microscopic fossils (the remains of calcareous nannoplankton, coccolithophores) from various eras. Because of their evolutionary rates, these are time-specific. Nanofossils are very plentiful and it is distributed widely in the areas. There are various numbers of beneficial nanofossils which include radiolarians & foraminifera. To date, marine sediments are the primary methods.

• Trilobites: During the Paleozoic Era (540 to 245 mya); they were common. About half of the Paleozoic fossils are trilobites. At the beginning of the Paleozoic Era, they evolved whereas went extinct during the late Permian period i.e. 248 million years ago.

 

Merits of Index Fossils

Various merits of Index Fossils are mentioned below:

• These fossils are used by geologists as well as palaeontologists as significant aids in order to determine the correlation as well as the age of rock sequences or patterns

• If we talk about microfossils, when required as well as accurate knowledge from the fossils is being collected, after that, these are generally used by oil prospectors along with other industries which are interested in mineral resources.

• By usage of some physical or biological methods, stratigraphic correlations can also be made.

• Besides the above points, lithologic similarity may also be ascertained between the various rock units by the usage of one or two marker beds.

• It helped and played a vital role in establishing the Continental Drift Theory.

 

List of Index Fossils

Index Fossil Examples:  Some of the common index fossils are given below along with their name, time they represent as well as images:

Time: Early Pleistocene 0.5 million

 

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Time: Quaternary Period 1.8 million

 

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Time: Tertiary Period

 

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Time: Cretaceous Period 145 to 66 million years ago

 

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Time: Jurassic Period

 

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Did you know?

Because of the evidence of the index fossils, Alfred Lothar Wegener was able to establish as well as present his ” Continental Drift hypothesis ” in 1912. According to this, all the continents of the world that we can see today have been originated from a single supercontinent i.e Pangea and breaking the Pangea into smaller pieces leads to drifting away of these pieces from each other around 200 mn years ago which leads to the formation of present continents. He found that fossil remains, as well as the structure of the rocks around the coastlines of South America, Africa and India, were similar to each other despite being separated by oceans such as the Atlantic and the Indian Ocean. Even fossils of tropical plants such as ferns, cycads etc are being found in the Arctic island, Spitsbergen. Thus, the presence of index fossils leads to the verification of the theory of Continental Drift.

 

Conclusion

To conclude, we can say that index fossils are considered as commonly found as well as widely spread & distributed fossils which are limited in the period. The architecture of geological time includes ages, epochs, periods, & eras, which index fossils helped to determine. They consist of remains of plants and animals along with other species in the layers of sedimentary rocks. If we talk about a good index fossil, two basic, as well as required features, are they should be abundant as well as vulnerable. This boom-and-bust character of fossils makes them a good fossil for geologists and palaeontologists. Here, we have covered the index fossil concept comprehensively along with index fossil example & index fossil definition, merits, etc. which will be helpful in Geography, Geology and Palaeontology, etc.

A map is a symbolic representation that emphasizes relationships, such as objects, regions, or themes, between elements of a certain space.

Most maps are static, fixed on paper, or some other durable medium, while others are dynamic or collaborative.

The study and practice of creating representations of the Earth on a flat surface is cartography or map making, and one who makes maps is called a cartographer.

Road maps are perhaps today’s most widely used maps and form a subset of navigational maps, including aeronautical and nautical maps, maps of the railway network, and maps of hiking and cycling. In terms of quantity, local surveys carried out by municipalities, utilities, tax assessors, emergency service providers, and other local agencies are likely to make up the largest number of map sheets drawn. Maps can also be used to depict contour lines indicating constant elevation, temperature, precipitation, etc. values.

World maps or large regions are mostly either ‘political’ or ‘physical’. The main aim of the political map is to display territorial borders; the physical purpose is to show geographical characteristics, such as mountains, the form of soil, or the use of land, including infrastructures, such as roads, railroads, and buildings. With contour lines or shading, topographic maps suggest elevations and relief. Not just the physical surface, but features of the underlying rock, fault lines, and structures of the subsurface are shown by geological maps.

What is a Globe?

A spherical model of the Earth, of some other celestial body, or a celestial sphere is a globe. Globes serve similar purposes to some maps but do not distort the surface they depict except to scale it down, unlike maps. The model globe of the Earth is called the globe of the Earth. A celestial globe is called a model globe of the celestial sphere. A world displays details of its topic. Landmasses and water bodies are shown by a terrestrial globe. It could reveal nations and major cities and the network of lines of latitude and longitude. To show mountains and other large landforms, some have elevated relief. A celestial globe shows notable stars, and other prominent astronomical objects can also show positions. It will usually split the celestial sphere into constellations, too. The apparent locations of the stars in the sky are displayed by celestial globes.

Distinguish between Globe and Map

What is Atlas?

A set of maps is an atlas; it is usually a package of World maps or an area of the Earth.

Traditionally, atlases were bound into book form, but many atlases are in digital formats today. In addition to the presentation of geographic features and political borders, geopolitical, social, religious, and economic statistics are also included in many atlases. They also have data about the map and its positions.

Types of Atlas

A travel atlas is designed for easy use during travel and sometimes has spiral bindings so that it can be folded flat (such as the popular A-Z atlases of the Geographers’ A-Z Map Company). It has maps with a broad zoom, so it is easy to check the maps. As a road map, a travel atlas can also be referred to.

A desk atlas is equivalent to a reference book. It can be in the form of a hardback or paperback.

Atlases of the other planets (and their satellites) are visible in the Solar System.

The Atlases of anatomy exist, mapping organs or other organisms of the human body.

Differentiate between Map Globe and Atlas?

Loess, a German term meaning “loose,” is derived from wind-deposited accumulation. It was first used in 1821 in the Rhine Valley Loess.

Define Loess Soil or What is Loess in Geography?

You can define Loess soil as a type of soil that is generated by the influence of wind. Loess has no stratifications, which is its most distinguishing feature.

Sedimentary material of the silty or loamy variety that is typically yellow or brown in colour and that is mainly deposited by the wind is known as loess. Silt-sized granules that are weakly cemented by calcium carbonate make up the bulk of loess. Vertical capillaries greatly assist in fracturing the silt and forming vertical bluffs, making it highly porous and homogeneous. 

There are several types of thick loess plain blankets, the most common of which is formed of loess packages ranging in thickness from three to 16.5 feet, each of which is interspersed with layers of sediment, sand, and similar stuff. The loess complex is made up of all of these elements. 

Sandy Loess, Clayey Loess, Loessial Sand, and Loess Loam are all regional varieties of loess that form a loess series, along with true loess. To identify between individual loess elements, workers in different areas or nations have varied interpretations of the many sediment types that compose the series.

Properties of Loess

Loess soil is homogeneous and is also highly porous. The features of loess make it to be the most fertile soil among all the other types. The major grain-size fraction of loess is from 0.02 to 0.05 mm, known as the loess fraction that includes granules of medium-grained dust. A variety of grain-size analyses show that this percentage makes up around half of the total. Nearly half of the particles are smaller than 0.005 mm, making up between 5 and 10% of the total. With increasing distance from the source of dust, the grain-size distribution in various loess zones moves toward finer grains (e.g., eastward from Sand Hills, Neb.).

As porosity declines, the moisture content of loess rises from 10% to 15%. Its porosity ranges from 50 to 55 per cent at the surface to around 10 metres below the surface (33 feet). At a depth lower than this, the grain-size distribution affects the porosity. The porosity of the loess can drop from 34% to 46% if clay is added. Sandy loess has a porosity of roughly 60%.

As porosity declines, the moisture content of loess rises from 10% to 15%. Its porosity ranges from 50 to 55 per cent at the surface to around 10 metres below the surface (33 feet). At a depth lower than this, the grain-size distribution affects the porosity. The porosity of the loess can drop from 34% to 46% if clay is added. Sandy loess has a porosity of roughly 60%.

Distribution and Classification of Loess

The distribution of Loess throughout the world is quite more as compared to many types of soil. In China along the Huang Ho River, in Inner and Central Asia, in Kazakhstan, Uzbekistan and the foreland of the Tien Shan, in Siberia along Lake Baikal and the Lena River, and vast regions in the southern catchment areas of the Ob and Yenisey rivers, the world’s largest loess-covered regions are located between latitudes 55° and 24° N. Many regions in Europe, including the South Russian Plain, have an extensive, uninterrupted loess cover. 

Loess is also found in prominent spots and belts in the Danube Basin, the Rhine, the German-Polish plain, and the Paris Basin. In addition, the plains of the Platte, Mississippi, Missouri, and Ohio rivers and the Columbia Plateau in North America are covered in loess. Argentina, Uruguay, and sections of New Zealand all have “pampas loesses,” or large areas of loess, between 30° and 40° S latitude.

They can be found on a wide range of relief features, including plains, river valley slopes, pediments on the forelands of mountains, and pediments. Europe, Inner Asia, and China all have loess up to 400–600 m above sea level; in the Himalayas, it can reach up to 4,000 m.

Based on physical and chemical features, the origin of loess is either completely or partially ignored in the lithological classification. In addition to loess, loessial and loess like deposits are also extremely common. Differences in the composition and qualities of silt and other components (clay, sand and lime) and in colour, porosity, strength and plasticity of loess deposits are significant.

What are Loess Rocks?

Silt-sized granules that are weakly cemented by calcium carbonate make up the bulk of loess and are known as Loess Rocks. Vertical capillaries allow the silt to fracture and form vertical bluffs, making it homogenous and highly porous.

Before getting into the intricacies of Mercator projection, let us understand what is map projection. A map projection is one of the numerous methods to represent the 3-dimensional surface of the earth on a 2-dimensional plane in Cartography. It is a way to flatten a globe’s surface into a plane to make a map. This conversion requires a systematic transformation of the latitudes and longitudes from a particular location of the world on a plane. All projections of a sphere on a sheet distort the surface in some way or the other. Depending on the map’s purpose, some of the distortions are acceptable, and others are not. The primary mercator meaning of map projections is to preserve some of the original sphere-like properties at the expense of others. The study of map projections is the examination of the distortions.

What is a Mercator Projection?

The Mercator projection is a cylindrical map projection presented by the Flemish geographer and cartographer – Gerardus Mercator – in 1569. Now, you may ask what a cylindrical map projection is. In Cartography, any map projection of the terrestrial sphere done on the surface of a cylinder unrolled as a plane is known as a cylindrical projection. Mercator projection became the standard projection for navigation due to its ability to conserve lines of constant course; that is, it represents the north as up and south as down everywhere while preserving local directions and shapes. The Mercator projection is derived mathematically. The meridians are equally spaced vertical lines, and the latitudes are parallel horizontal straight lines that are spaced farther apart as the distance from the Equator increases.

The prime detriment of the Mercator projection is that it inflates the size of objects away from the Equator. The inflation is minuscule near the Equator and increases latitude, and becomes infinite at the poles. The result of such distortion is that areas like Greenland and Antarctica appear much more extensive than they are. For example, on a Mercator projection, the landmass of Greenland appears greater than that of the continent of South America; although, Greenland is even smaller than the Arabian Peninsula.

The Working of Mercator Projection

You can understand the construction of the Mercator projection by taking a cylinder with a globe inside. You should light up the globe from within so that you can project an image of the earth on the surrounding cylinder. As the cylinder only touches the globe at the Equator, the parallels along that specific region are entirely accurate. Furthermore, as the cylinder is perpendicular to the globe, the lines of longitudes and latitudes appear straight instead of curved lines when transferred to the cylinder. 

We can imagine the Mercator chart as a small section peeled from the cylinder and laid flat. The Mercator chart is mathematically constructed, which means that the distance representing the spacing between meridians and parallels is numerically derived.

The graticule transferred on to the cylinder has a consistent 90-degree angle between the parallels and meridians. Thus, the rhumb lines are also straight on the Mercator projection.

Uses of Mercator Projection

1. The Mercator projection is significant for navigation, and almost every marine chart is based on it.

2. Street mapping services such as Google Maps, Bing Maps, MapQuest, etc., use a Mercator called Web Mercator for their map images.

3. Mercator projections were vital for the mathematical development of plate tectonics during the 1960s.

Critique of the Mercator Projection

Owing to its expansive land distortions, many consider Mercator projection unsuitable for use in world maps. However, on account of its common usage, the Mercator projection has influenced people’s view of the world. Since it shows countries near the Equator as too small compared to Europe and North America, it has compelled people to consider those small countries as less critical. As a result, modern atlases no longer use the Mercator projection for world maps or areas far away from the Equator. Mercator projections, currently, are found in maps of time zones.

Conclusion

The topic of Mercator projection may seem very tricky to grasp. However, the concept does get manageable with thorough understanding, regularly solving questions and numerical, practising papers and proper revision. Before understanding the whole idea, we must grasp the basics of map projections and then move to Mercator. Past years’ question papers, along with ‘s concept pages, are the perfect companions to guide you through the journey of absorbing knowledge.

Facts About Mercator Projection

• The parallels and meridians on the Mercator are straight and perpendicular to one another. This phenomenon is typical among all cylindrical projections.

• The Mercator is a conformal map projection which means that the angles around all locations are preserved.

• All latitudes beyond 70 degrees north or south of the Mercator projection are unusable as the linear scale becomes infinitely large at the poles.

• A Mercator map can fully show the polar areas.

• The two features of a Mercator map – conformality and straight rhumb lines – make the projection uniquely appropriate for navigation.

• The Mercator projection was the most commonly used projection for world maps during the 19th and 20th centuries.

You must have visited the mountain regions or the hill stations for your holidays to enjoy the beautiful natural scenery and the smooth and relaxing weather of that region. The mountain regions matter a lot for especially those people who live in the hot climate regions and these mountain regions are considered as the perfect escape from those hot regions. In this article, we will be talking about one of the major landforms, the Mountains. We will learn about the rocky mountain landform’s meaning, definition, features, types and how they are formed, and other related concepts. This article will help you to cover one of the important topics of Geography of major landforms of the Earth and will help you in your studies as well.

Mountain Landform Definition and Meaning

It is one of the most important physical features of the Earth. It is a natural elevation due to various factors of the Earth and this elevation is higher than the surrounding areas. It can have a narrow shape at the top and a broader shape at the bottom. They can be of conical shapes or rounded figures. Temperature goes on decreasing with their heights and they are generally covered with snow. When a number of mountains are arranged in a line, then that landform is termed as mountain range landform.

As per the Cambridge dictionary, “mountain means a raised part of the Earth’s surface, much larger than a hill, the top of which might be covered in snow.”

Types of Mountain Landforms and Their Formation

The various types of mountain landforms and how they are formed is mentioned below:

Volcanic Mountain

These are the mountains that are formed because of volcanic activity. When the lava comes out at the surface through a crack in the earth called a vent and starts piling up around this vent, then after some time it takes the shape of a mountain with a conical shape. There can be different types of volcanic mountains such as,

• Shield volcanoes are those which are not too steep and lava usually flows up to a large distance. These are considered the largest of all the volcanoes.

• Cinder Volcanoes are those which are having a steep slope and a crater on the top. In this type of volcano, the lava blasts out explosively.

• Composite volcanoes are those in which there are one or more vents and lava gets collected in the form of layers over layers.

• Caldera is a kind of volcano in which a sudden volcanic eruption happens.

Fold Mountains

When two continental plates move towards each other and the rocks or debris etc. Start folding into a structure which leads to the formation of fold mountains. These are formed through an orogeny process which takes several years. These mountains are formed at convergent plate boundaries or continental collision zones or compression zones. The stress in these zones due to move towards each other leads to mountain formation. For example, the world-famous mountain ranges, the Himalayas, the Andes, the Alps are examples of fold mountains.

These kinds of mountains have rounded features and have low elevation because of denudation and are 500 million years old. Examples: Laurentian mountains, Algoman, etc.

Earlier these mountains were also very high but due to erosion, they have now rounded features with medium elevation. Their origin belongs to the territory period.

Examples, the Appalachians, the Aravallis, etc.

They belong to the territory period. They have high conical peaks and rugged relief. Examples, the Himalayas, the Andes, the Rockies, etc.

Block Mountains

These are the Mountains that are formed because of the faults in the Earth at a large scale and when large pieces or blocks of the Earth get displaced horizontally or vertically. They are formed when two tectonic plates go away from each other, leading to faulting in Earth and these are also called fault-block mountains. It can be seen in the following diagram that how they are formed. The uplifted part is called horst and the lower part is called graben. The formation of rift valleys is being seen between the block mountains. An example of it is the Eastern African Rift valley. 

These mountains are formed when the central part moves downwards and forms a rift valley but sometimes the central part remains the same and the surrounding sides subside which leads to Plateau formation.

Dome Mountains

Magma when reaching the surface we see a volcano but when it does not crack the surface and just pushes the rocks to create rounded swelling and when this magma cools with time, the hard rock will look like a dome. They are not as high as fold mountains. For example, Half dome mountain, Sierra Nevada Range, California. They are also not so easy to identify and usually, satellites are used to identify rounded structures.

Uses of Mountains

• They provide shelter to around 12% of the total population of the world.

• They are a great source of fresh water and many rivers generally originate from the mountains.

• They also support varieties of flora and fauna in the regions.

• The presence of the flora and fauna in the mountain regions varies and depends on the different locations.

• Several hill stations are also found here which attracts a large number of tourists and is a great source of income for that region. 

• It plays a vital role for mountaineers and rock climbers. People usually visit mountain regions for trekking and camping purposes as well.

Did you know?

• There are mountains under and above sea levels.

• Their heights are notes as per the height above the sea level.

• This mountain landform covers about 1/5th of the landscape of the Earth.

• They are sources of freshwater, recreation activities, livelihood, vegetation, and wildlife, etc.

• The Olympus Mons and Mount Everest are the highest mountains of the whole solar system and Earth respectively.

• The blue ridge mountains landforms are one of the most famous mountains in the world because of their blue appearance.

Conclusion:

Thus, in this article, we have covered one of the major landforms, the Mountains. These are the naturally elevated landforms of the earth. We have learned rocky mountain landforms, types of mountain landforms, their various features, highlands landforms, etc. This article will help you to understand one of the important landforms of the Earth and this will help you in studying landforms in Geography and Earth science. These notes will be helpful for students of Class 9 or upper classes. These will also increase your knowledge about mountains and how they are formed. You can find out more interesting articles on various subjects on our website which are written by subject matter experts to help you in your studies.

We have read about the old and young rocky mountains landforms, let’s practice some FAQs related to it: