Question

Which of the following groups constitutes the basic rock forms?
A.Sandy, Igneous, Metamorphic
B.Igneous, Sedimentary, Metamorphic
C. Lignite, Volcanic, Sedimentary
D. Sandy, Volcanic, Igneous

Answer 1

Hint:
The crust is the uppermost layer of the earth. The thinnest layer of earth is the crust. The earth’s crust is made by various types of rocks. A Rock means any natural mass of mineral matter that makes up the earth’s crust. Rocks can be of different colors, sizes, and textures.

Complete solution:
 Rocks are categorized by the minerals comprising its chemical composition and the way in which it is organized. Igneous, Sedimentary, Metamorphic constitutes the basic rock forms. When molten magma cools and becomes solid igneous rocks are formed. They are called primary rocks. Intrusive rocks & extrusive rocks are types of igneous rock. When magma rapidly cools down after coming on the earth’s surface it forms extrusive rocks whereas magma cools down deep inside the earth’s crust it forms intrusive rocks. Because of some reason like a roll down the rocks crack & hit each other and broken down into small fragments. It transformed into sediments and these sediments are compressed & hardened to form layers of rocks. It calls the sedimentary rocks. Under great heat & pressure, the sedimentary and igneous rocks can change into metamorphic rocks. One type of rock can change into another type of rock under some conditions. This process is called the rock cycle.

Hence, the correct answer is option B.

Note:
After the crust, another layer is called the mantle. Deccan plateau is formed by basalt rock(Extrusive igneous rocks) and granite is a good example of intrusive igneous rocks. The red fort in Delhi is made up of sandstone(Sedimentary rock) whereas the Taj Mahal is made up of marble(Metamorphic rock).