NCERT Solutions for Class 7 Social Science
Geography Chapter 2 Inside Our Earth
Question 1(iv) Page No. 10
NCERT Academic Session 2023-2024
How are extrusive and intrusive rocks formed?
Share
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Formation of Extrusive and Intrusive Rocks:
Extrusive Rocks:
– Formation: Result from rapid cooling of lava on the Earth’s surface during volcanic eruptions.
– Cooling Rate: Quick cooling leads to fine-grained or glassy textures.
– Examples: Basalt and obsidian are common extrusive rocks.
Intrusive Rocks:
– Formation: Formed from slow cooling of magma beneath the Earth’s surface.
– Cooling Rate: Slow cooling results in coarse-grained textures.
– Examples: Granite and diorite are typical intrusive rocks.
Distinct cooling rates influence textures, creating differences between extrusive and intrusive rock types.