Tuesday, August 18, 2009

ATTENTION - SHALL WE REVISE TOPOSHEETS?

HELLO,
As per the requests of many, I'm going to begin revision on 'INTERPRETATION OF TOPOSHEETS'. So , I will begin with a small test on toposheets. I will display a toposheet and few questions on it. You study the map carefully and then answer the questions and mail to me. I will send the answers to all those who mail me. As soon as I get the answers, I will send you the correct anwers. If you really want to do well, then you must prepare for the test. Check the blog or your text books and learn all the signs and symbols. And once you begin your test, my suggestion is not to look at the book. You attempt your answers and then send it to me. Once you send me the answers, you can check it out. My email id is: brhector21@gmail.com
When you send me the answers, write your name, class and school so that i dont get confused. Answers will not be displayed on the blog. You can take your own time to send the answers but dont wait too long because more tests will be conducted. All the material that is in the blog will be edited again. More information will be given . If you have any interesting or good material in geography, please do send me so that other students also benefit. You are also requested to send materials on other subjects so that I can share it with other students like.
Be happy.

Saturday, August 15, 2009

TYPES OF ROCKS



















What occurs in the Earth to change these rocks?


- Pressure from overlying rock layers
- High heat, but not enough to melt the rockRocks may be flattened or bent or atoms may be exchanged to form new mineral















You can think of metamorphic rocks as a squished peanut butter & jelly sandwich in your lunch.








How are metamorphic rocks classified?

- Non-Foliated—No bands are formed

- Example: marble formed from limestone













Non-foliated metamorphic rocks include marble, which comes from limestone, and quatzite, which comes from sandstone






- High temperatures and pressures at depth cause changes in mineralogy, texture, and composition
–Changes take place in Solid State by recrystallization and chemical reactions
–Temperatures greater than 250°, less than 700°
- Regional Metamorphism - High pressures and temperatures derive from regional collision, deformation and mountain building.
- Contact Metamorphism - Locally high temperatures, adjacent to intrusions.

Types of Metamorphic Rocks

























What is a metamorphic rock?

A metamorphic rock is any sedimentary or igneous rock that has been changed, or morphed, because of pressure and heat.
- Marble
- Schist

How is a metamorphic rock made?

Metamorphic rocks are made deep inside the earth where heat and pressure change the rocks











IGNEOUS ROCKS 1














Monday, August 3, 2009

JULY TEST- CLASS X

DON BOSCO ICSE SCHOOL,
Geography
Class: X Duration: 1 hour Max Marks: 40
Attempt ALL questions.

QUESTION 1
On the outline map provided, mark and name: (10 marks)
a. The capitals of Bhutan
b. The commercial capital of Pakistan
c. The Bolan Pass
d. The latitude that divides the sub-continent into two climatic zones
e. An area of coal production in India
f. An area of alluvial soil in Pakistan
g. The Karakoram Range
h. An off-shore oilfield of India
i. The Deccan Plateau
j. The Bay of Bengal branch of monsoons

QUESTION 2
a. Why is literacy high in Sri Lanka? Who are the Moors and Burghers? (2 marks)
Education is compulsory and is free even at the university level resulting in nearly 95% literacy.
Moors are the descendants of Arabs -Islam.
Burghers are the descendants of Europeans who married Sri Lankans.

b. Why is agriculture of not much importance in Nepal? In which part of Nepal is it predominant? (2 marks)
Nepal, is being mostly mountainous, hardly any arable land is available except in the Kathmandu Valley.

c. Name and give the chief features of three major land regions of Nepal. (3 marks)
The Himalayas in the North have steep valleys covered by glaciers which run the entire length of Nepal.
Forests are found on lower slopes – higher regions have only grass. Winters are generally bitterly cold here.
The hills and valleys, south of the Himalayas, have some arable agricultural land yielding maize, rice and facilitating cattle-rearing . Bamboo trees and grass grow here. The weather is chilly but dry.
The Tarai Region in southern Nepal is fertile and has a variety of crops and livestock. The climate is tropical.

d. With reference to Chittagong Hill Tract, (3 marks)
i. Where is it located?
In south-east Bangladesh- a small, hilly tract stretching in a north-south direction. It is made up of soft, clayey soil.
ii. Briefly describe its flora and fauna.
Cheetahs, mongooses, snakes, crocodiles, elephants, leopards and the major animals found.
iii. Why is Chittagong important?
Chittagong is the chief seaport and commercial centre.
QUESTION 3
a. Which two countries of South Asia have low density of population? Give reason. (2)
Bhutan and Nepal are the two countries of South Asia that have low density of population.
These countries have low density because of rough terrains.

b. With reference to South Asia, name (2 marks)
i. The smallest country - Maldives
ii. The largest country - India

c. Explain the impact of Himalayas on the occupation of the people. (3 marks)
* The rivers originating from the Himalayas are responsible for the formation of plains. These plains provide fertile soil.
* Himalayan slopes are rich pasture lands for raising sheep and cattle.
* Slopes of Himalayas have been terraced for cultivation of fruits, food crops and plantation crops.

d. Why most of the peninsular rivers have straight and linear courses? (3 marks)
* Due to gentle slope, the intensity of erosional activity is less.
* The hard rock bed and lack of silt and sand does not allow meandering.
* During most of the year, they have less water.

QUESTION 4
a. Name a rock from which black soils are formed. Write one characteristic of the soil. (2 marks)
Igneous rocks .
· Black soils are made of extremely fine material.
· They retain moisture.
· These soils are rich in nutrient.

b. Name the type of soil found on the summit of the Eastern Ghats. How is it formed? (2 )
On the summit of Eastern Ghats, the main soil is laterite soil. Laterite soils are formed under alternating wet and dry spells. They are composed of a mixture of hydrated oxides of aluminum and iron.

c. “Proper farming techniques can help in soil conservation’. Explain by giving three examples. (3 marks)
· Terracing of hill slopes is effective in controlling soil erosion. Terracing is cutting into the hill slopes in a series of large steps made up of flat fields.
· Constructing bunds across hill slopes and filed boundaries is effective in reducing soil erosion. Bunds arre low mud walls or embankments that help to obstruct the flow of water.
· Contour ploughing should be practiced. It involves ploughing along the outline of the field in a circular manner. This prevents the soil from being washed away by running water.

d. Distinguish between alluvial and black soil keeping in mind texture, minerals and crops associated. (3 marks)
TEXTURE: Alluvial soil is coarse in upper regions, medium in the middle and fine in the lower regions whereas black soil is fine grained and moisture retentive.
MINERALS: Alluvial soils are rich in potash whereas black soils are rich in lime, iron and potash.
CROPS: Rice, wheat, and surgarcane grow well in alluvial soil. Cotton, sugarcane and tobacco are grown well in black soil.

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