lecture 3- igneous rock

Question 1

what is igneous rock?

Answer 1

direct cooling and solidifying of magma

Question 2

what are the properties of igneous rock?

Answer 2

crystal structure, strong and durable

Question 3

what are the 2 types igneous rock? and explain them

Answer 3

extrusive - formed on earth’s surface (lava), cools rapidly (small crystals)
intrusive - formed below the ground (magma), cools slowly (larger crystals)

Question 4

what are the 2 main types of igneous rock?

Answer 4

granite (intrusive)

basalt (extrusive)

Question 5

what is batholith?

Answer 5

large was of intrusive rock that has been formed due to the cooling of magma deep in the earth’s crust

Question 6

what is sill?

Answer 6

sheet d intrusive igneous which have been trapped between layer of old sedimentary rock

Question 7

what is dyke?

Answer 7

when magma flows through fractures and solidifies as a sheet intrusion cutting across the layers of rock

Question 8

what are pumice and obsidian, and what is significant about them?

Answer 8

pumice - frothy lave from water/ high pressure

obsidian - glass structure from rapid cooling

Question 9

what is meant by “glass structure”

Answer 9

the opposite of crystal structure