Meaning of Metamorphic Rocks
They are a class of rocks that result from the alteration of pre-existing rocks in response to changing environmental conditions or any natural situations without any liquefaction process, such as fluctuations with temperature, pressure, and mechanical stress, and the inclusion or subtraction of any available chemical components.
Definition and Examples
Metamorphic rocks arise from the transformation of existing natural rock substances to new types of rock without any exterior liquefaction manually done, in a process called metamorphism. During this process, the original rock is subjected to temperatures of more than 150-200 degrees celsius and often pressures of more than 100 megapascals resulting in vast physical and chemical modifications.
Types and Characteristics
Common metamorphic rocks varieties include phyllite, schist, gneiss, quartzite, and marble.
Metamorphic rocks can be classified into two main categories based on the way they are formed - those that are foliated as they have been formed due to high pressure and under shear stress and those that are not foliated under any form of pressure.
Types of Metamorphism
The three major types of metamorphism are Contact, Regional, and Dynamic metamorphism.
Contact Metamorphism occurs when hot lava comes in contact with an already existing body of rock. When this happens the existing rock's current temperature rises and also becomes infiltrated with fluid from the volcano.
Regional Metamorphism occurs over a much larger surface area. This type of metamorphism produces and forms rocks such as gneiss and schist. Regional metamorphism is mainly caused by large geologic processes such as mountain-building.
Dynamic Metamorphism, like regional metamorphism, also occurs because of mountain-building. These huge forces of heat and pressure that are applied naturally cause the rocks to be bent, folded, crushed, flattened, and sheared in any manner. As hard as or even harder than igneous rocks, metamorphic is almost always harder than sedimentary rocks. They form the roots of many mountain chains and are exposed to the surface after the softer outer layers of rocks are eroded away due to any natural calamities caused.
FAQs on Metamorphic Rocks
1. What are some examples of Metamorphic Rocks?
There are two types of metamorphic rocks:
Foliated Rocks: Examples: Slate, schist, amphibolite, gneiss, migmatite, phyllite, etc.
Non-foliated Rocks: Examples: Amphibolite, quartzite, marble, hornfels, etc.
2. Write uses of Metamorphic Rocks in everyday life.
Quartzite and marbles are most commonly used metamorphic rocks in our day-to-day life. The marbles are available in a collection of different colors that were deformed into coils while the rock was ductile. The marbles are often used mostly as a decorative stone in buildings and some marbles are considered a better quality stone, carved into statues, however, they lack a variety of colors.
3. Write some examples of Sedimentary Rocks.
The examples of sedimentary rocks are:
A. Clastic Sedimentary Rocks: These rocks are from mechanical weathering rubble.
Breccia
Conglomerate
Stale
Slit
Sandstone
B. Chemical Sedimentary Rocks: They are formed when dissolved minerals precipitate from the solution.
Rock salt
Chert
Iron ore
Flint
Limestone
Dolomites
4. What minerals are found in the Metamorphic Rock?
Common minerals in metamorphic rocks are: quartz, feldspar, mica, calcite, and hornblende.
Index minerals in metamorphic rocks determine how much rock material was metamorphosed or transformed into another form. It is also called the grade of metamorphism.
Index minerals include the following:
Chlorite
Garnet
Epidote
Staurolite
Kyanite
Sillimanite
5. Is Metamorphism an easy chapter?
Physics is one of the important subjects both in board exams as well as competitive entrance exams that will decide which course you can get into. You will have to concentrate more on this metamorphism chapter by understanding the concepts well. Scoring a 100 in physics is hard and it requires a really good amount of practice and revision with revision notes and past years' question papers or sample question papers along with sincere efforts. Hard work with a strategic plan will surely help in scoring better.
6. Is the Metamorphism chapter included in the NCERT syllabus?
Yes, the Metamorphism chapter is included in the NCERT syllabus available on the Vedantu website with solutions that are indeed very much sufficient to score the desired marks in the Physics paper. By practising with the past years' question papers and other sample question papers available it is definitely highly possible to score well. The CBSE syllabus has many interesting and challenging concepts to be understood in the case of Metamorphism. So, reading and understanding the concepts and topics clearly is as important as revising them. Just as you read concepts to solve a few problems will instill it rigidly in your mind.
7. Will the CBSE Physics examination be difficult if you skip this Metamorphism chapter?
The paper will be very easy and even easier to score if you practice well but if you happen to skip or neglect any particular chapter as a whole and then if you get any questions from that chapter it might be difficult for you to score full marks without knowing the concept. You should learn all the concepts well and prepare revision notes for you to revise before exams. The overall level of the paper will not be too long and will be really easy to write when prepared well. Most of the students find this paper easy and hence, they are expecting to score good marks. It requires that much effort like any other subject and students try to score really well in this paper by preparing each and every chapter included in the syllabus.
8. Does the Metamorphism chapter require special attention to present well in the paper?
It is quite obvious that an answer sheet, which is neat and approachable, derives more marks than the one which is messy. Use appropriate colour ink to present your paper and highlight the important points with necessary diagrams. Many students strike out the lines and words often in the answer sheet, which will destroy the neatness and cleanliness of the sheet. Metamorphism concepts can be better explained with neat diagrams and illustrations that will fetch you extra marks. These are some simple things you can do in your exams that you often ignore but these can help you score some extra marks. And those few extra marks from one chapter will help in boosting the overall percentage in the exams to quite an extent.
9. Is it essential to identify and work on important points in Metamorphism?
If you have taken up this Metamorphism chapter, you might be good in one part of the chapter, but find it difficult to concentrate on the diagrams or explanation part of the same chapter. Then you should identify your weak areas and start working on them so that these tough chapters do not impact the overall percentage. Most students will show less interest in studying chapters they are weak at, and this is the biggest mistake. Instead of running away from the chapter, try finding the weak points and work on them to turn them into your strong areas.
