PPT: Types of Rocks & Sea Floor Spreading Theory | Geography for UPSC CSE PDF Download

 Page 1


GEOGRAPHY 
CRASH COURSE
CAPSTONE IAS LEARNING
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GEOGRAPHY 
CRASH COURSE
CAPSTONE IAS LEARNING
TYPES 
OF 
ROCKS
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GEOGRAPHY 
CRASH COURSE
CAPSTONE IAS LEARNING
TYPES 
OF 
ROCKS
• Rocks are an aggregate of one or more minerals 
held together by chemical bonds.
• Feldspar and quartz are the most common 
minerals found in rocks.
• The scientific study of rocks is called petrology.
Page 4


GEOGRAPHY 
CRASH COURSE
CAPSTONE IAS LEARNING
TYPES 
OF 
ROCKS
• Rocks are an aggregate of one or more minerals 
held together by chemical bonds.
• Feldspar and quartz are the most common 
minerals found in rocks.
• The scientific study of rocks is called petrology.
Major Types of Rocks
•On the basis of their mode of 
formation, rocks can be classified 
into the following three types:
•1. Igneous rocks
•2. Sedimentary rocks
•3. Metamorphic rocks
Page 5


GEOGRAPHY 
CRASH COURSE
CAPSTONE IAS LEARNING
TYPES 
OF 
ROCKS
• Rocks are an aggregate of one or more minerals 
held together by chemical bonds.
• Feldspar and quartz are the most common 
minerals found in rocks.
• The scientific study of rocks is called petrology.
Major Types of Rocks
•On the basis of their mode of 
formation, rocks can be classified 
into the following three types:
•1. Igneous rocks
•2. Sedimentary rocks
•3. Metamorphic rocks
Igneous Rocks
• The word igneous is derived from the Latin word ‘ignis’ 
meaning fire. These rocks are of thermal origin and are 
associated with volcanic eruptions. 
• These rocks have been formed due to solidification of 
hot and molten material called magma.
• It is believed that at the time of its birth the Earth was 
in a molten state. The igneous rocks were the first to be 
formed as a result of the solidification of the outer layer 
of the Earth. 
• Thus, igneous rocks are also known as the primary 
rocks. They can be divided into two types— intrusive 
igneous rocks and extrusive igneous rocks