|History & Civics|
1. Explain briefly bow plate tectonics cause formation fold mountains.
The formation of fold mountains is caused by the compression of sedimentary rocks resulting in folding the layers of rocks creating the fold mountains.
2. What are known as epeirogenic movements?
The movements such as uplift and submergence working in vertical direction are known as epeirogenic movements. 'Epeiros' in Greek means continent 'genic' means building. As this movement created continents coming out higher from the oceans.
3. Name four relief features on the surface of the earth?
The four major landforms are mountains, plateaus, plain valleys and basins.
4. Give one example of volcanic mountains.
Volcanic mountains are formed by erupting magma from the inner core on the surface . Example, Mt. Krakatoa is an active volcano on the western side of Java.
5. How are erosional plains formed?
Erosional plains are formed by the agents of erosion in millions of years, when the higher landforms are eroded into level plain areas. Example, Lorraine plain in France.
6. Distinguish between Fold Mountain and Block Mountain.
|Fold Mountain||Block Mountain|
|Fold mountains is built
by the tectonic forces
folding the sedimentary
|Block mountain is built after
the submergence of a landmass
leafing behind the big blocks on
the both sides.
|These are formed of light
Example, the Himalayas
|These are formed by solid rocks
standing on the body sides of a
Example, Vosges mountain in
7. Distinguish between Tectonic mountain and Volcanic mountain.
|Tectonic mountain||Volcanic mountain|
|It is built by the tectonic
force working on the crust
of the earth.
|It is built by the volcanic eruption
from the interior of the earth.
|It is the result of upthrust
force of the tectonic
|It is the result of upthrust force of
magma coming up on the earth surface.
|It may be built by sedimentary
or metamorphic rocks.
|It may be built by crystalline igneous
rocks of particular composition.
8. Distinguish between Intermontane plateau and Piedmont plateau.
|Intermontane plateau||Piedmont plateau|
|It is a high plateau surrounded by hills and mountains.||It is a plateau between mountain and plain areas with steep slope towards plain.|
|The plateau of Tibet is the highest plateau between Himalayas and Kunlun||Potagonia plateau is an example of piedmont plateau.|
9. Distinguish between Structural plain and Erosional plain.
|Structural plain||Erosional plain|
|It is formed by the uplift of landmass by Diastrophic forces creating an extensive lowland.||It is formed by the erosion and deposition of large amount of debris and silt by the agent of change. Example water, wind and ice etc.|
|The Missouri - Mississippi plain of U.S.A. is an example, which came out of ocean by uplift force.||Northern plain of India is an example formed by the deposition of soil, silt by erosional forces. It is one of the largest alluvial plain.|
10. Explain the forces that cause development of landforms on the surface of the earth.
Water, wind and ice are three main forces that cause development of landforms on the surface of the earth. These forces are called exogenic forces. These work through erosion and deposition. Large alluvial plains, peneplains, coastal features, sand dunes and Barchans in hot deserts, glaciers and pointed snowclad peaks and amphitheaters etc.
11. Describe the characteristics of four different types of plateaus.
Intermontane plateaus are the highest plateaus between highest mountains, example, Tibetan plateau. Piedmont plateaus lie between mountains and plains with steep slopes to wards plains due to the force of flowing water downwards, example, Appalachian plateau of U.S.A., Patagonia plateau of South America. Volcanic plateaus are created by volcanic eruption and Lava flows, example, Deccan plateau of peninsular India. Uplifted plateaus are caused by the endogenic forces resulting in the dome shaped plateaus example, Chhotanagpur plateau in India.
12. Explain the chief characteristics of plains and their types.
The plains are the most preferred landforms for settlement due to the level land favourable for human activities. Structural plains are created by uplifting of a large landmass due to Diastrophic movements, example, plain of U.S.A. Erosional plains are formed by eroding highlands into plain areas, example, Lorraine plain in France. Srinagar Valley of Kashmir is the result of glacial erosion, Sahara desert plain is the result of wind erosion. Karst plains are created by erosion of limestone rocks by ground water, example, Karst plain of Yugoslavia. Depositional plains are caused by large scale deposition of debris and silt deposited by the running water or rivers, example, Northern plain of India.
13. Describe the direction in which the following mountain systems lie and also point out the continents where they are found.
(a) Alpine Himalayan System (b) Rocky-Andean System
(a) Alpine Himalayan System both run from West to Wast direction in Europe and Asia continents respectively.
(b) Rocky-Andean System both run from North to South in the western margins of North America and South America continents.
14. What are the different types of Geosynclines?
(i) Monogeosynclines — Long, narrow geosynclines along narrow water bodies take the shape of narrow mountains such as Appalachian mountains of North America,
(ii) Polygeosynclines — Geosynclines laid down in wide and long water basin take the shape of broad and long mountain ranges like Rockies in North America.
(iii) Mesogeosynclines — The geosynclines lying between Europe and Africa continents resulted in various mountain ranges. Examples, Alps and pyrenees in Europe, Atlas in Africa.
15. What are Block mountains? How are they formed?
Block mountains are formed on the both sides of a rift valley, which is formed by deep submergence of a large landmass leaving behind two raised platform type blocks known as Block mountains. These landforms are created by displacement of landmass along fault lines known as faulting.
16. How are peaks and ridges different from range and chain? Give examples.
Peaks are formed by resistant rock beds in dome-like or conical shapes and ridges are in the form of individual arch or block resulting by folding and faulting. Range is a linear arrangement consisting of large number of peaks and ridges meddled with valleys and a chain is the series of ridges in one line separated by trough like valleys. Mount Blanc is a peak in the Alps, Appalachian mountains are in the form of a ridge, the Himalayas are known as the Himalayan range and pyrenees present the example of a chain.
17. What are Plateaus? How are they different from mountains? Give suitable examples.
Plateaus are the tabular highlands with almost flat terrain with steep slopes in the margins which separate them from the surrounding low lying area. Their height is generally more than 150-200 metres. These are criss-crossed by river valleys and may be divided into smaller plateaus.
Due to being under continuous stress of elevation or submergence, the plateaus are made of hard crystalline rocks, while the mountains are made of light sedimentary rocks of tertiary age. Example, Deccan plateau, Colorado plateau, Brazil plateau and South African plateau are made of hard crystalline rocks rich in minerals and the Himalayan range is made of light sedimentary rocks of limestone and sandstone with a few minerals.
18. What is a Piedmont Plateau? How is it different from a continental plateau? Give suitable examples to illustrate.
The piedmont plateaus lie at the foot of the mountains. These are made of the debris and other material washed down the slopes of the mountains and after consolidation form a plateau like feature. These are narrow in width example, the piedmont plateau lying in the eastern margin of the Appalachians. Another example is of Patagonia plateau of South America which is in the form of an escarpment of 100-200 metres in height.
Continental plateaus are very extensive mostly surrounded by seas, rising abruptly from the bordering lowlands or seas. Example, Peninsular plateau region, Greenland and Antarctica.
19. Write short notes on the following:-
(a) Coastal plain (b) Karst plain
(a) Coastal plain :- As the word denotes, this plain is situated near the sea-coast by the action of sea-waves, known as sea-beach in the coastal margin. It is made of mud and sound. Example, the western and eastern Coastal plains of India.
(b) Karst plain:- It is made by the action of underground water. It is found in areas of limestone rocks; as the limestone is desolved into the water leaving behind pillars, pebbles and other fragments after the evaporation of water. The roof of Karst cave may fall down and give birth to a peculiar Karst plain.
20. Describe the characteristics of Alluvial plains.
Alluvial plains:- These are formed by the continuous large scale deposition of silt and debris by the rivers. The rivers coming down from the mountains in fast speed, Suddenly slow down reaching the plain adjoining the foothills, depositing heavy amount of debris pebbles at the foot of the hills. It is known as 'Piedmont Alluvial Fan', particularly known as 'Bhabar' in India. Another feature is the flood plain, which is created on the both sides of the river in plain area by the extension of flood water to long distances. Ox-bow lakes are the common features originated by the meanders of the rivers. Due to the changing course of rivers there are several levees and swamplands scattered throughout the whole surface. These plains are the most fertile basins due to the new layer of soil every year deposited by the river.
21. Write a note on the Delta plain. How are they different from drift plains?
Delta plain :- This plain is found near the mouth of the river joining the sea in its old stage. Due to extreme silting and dead slow speed of the river, the main river is channelised into several distributaries forming a fan-like shape or triangular shape as the Greek letter delta is shaped like a triangle. Ganga-Brahmaputra delta is the biggest delta in the world.
Drift plains are the result of drifting continental glaciers, leaving behind large deposits of moraines spread by the various streams emerging from the glacial sheet. Best example is the Canadian shield in North America rich in lakes and swift streams which have been used by man for inland waterways and hydroelectricity.
22. Why and how are plains the centre of all human activity. Illustrate your answer with suitable examples.
It is a well known fact that all the ancient civilizations originated along the river valleys. Example, Indus Valley, Yangtze basin, Ganga basin, Nile valley Mesopotamia civilizations. It was due to the availability of freshwater for drinking and other occupations, level land and suitable climate, too. Today, these basins are famous for full fledged agricultural occupations, heaviest road and railway and inland water transport. Mississippi basin is remarkable for the heaviest railway network in the world and Ganga plain is noted for the heaviest railway and road networks in Asia. The Plains provide all facilities and security of survival through agricultural, economic, transport and communication facilities. Besides this the plains are the best suppliers of irrigation and pipelines facilities for agricultural and industrial growth. Therefore, the plains are the most densely populated parts of the world illustrating the importance of the plains.
Practice in Related Chapters
|World Climatic Type|
|Hot Wet Equitorial Climate|
|Tropical Sudan Climate|
|Tropical Monsoon Climate|
|Intensive Agriculture in Egypt|
|Commercial Grain Farming in USA|
|The Mediterranean Climate|
|Hot Desert Climate|
|Temperate Continental Climate|
|China Type Climate|
|Lumbering in Canada|
|Temperate Continental Climate (Siberian)|
|Arctic or Polar Climate|
|Land forms of the Earth|
|Latitudes and Longitudes|
|Our World- Earth as a Planet|
|Structure of Earth|
|Materials of the Earth's Crust - Rocks|