Igneous rock

Question 1

What is a rock

Answer 1

A rock is a material that makes up the solid parts of the earth

Question 2

How to determine the identity of a rock

Answer 2

1 chemical composition of minerals in rocks
2 texture

Question 3

Igneous rocks are

Answer 3

Rocks that form when magma cools and solidifies

Question 4

Melting- Magma is..

Answer 4

liquid rock produced form under the earths surface

Question 5

Why do rocks melt

Answer 5

Temperature increases above rock or minerals melting point
After the sediments form, they are mostly transported by wind water or ice to a new location
Pressure, excess pressure is removed
Fluids , can be added to hot rock which decreases melting point

Question 6

Melting, crystallization

Answer 6

Partial melting- diff minerals have diff melting points
Fractional crystallization- removal of diff minerals from cooling magma

Question 7

Texture of igneous rocks

Answer 7

Intrusive- cooling solidification of magma deep inside crust magma
extrusive- cooling and solidification of LAVA at earth surface

Question 8

How are igneous rocks formed

Answer 8

Molten earth cooled- intrusive cooled below crust slow, larger crystals
extrusive- cooled on earths surface faster fine grain crystals or no crystals

Question 9

Difference between intrusive and extrusive

Answer 9

Where they are from
Size of crystals or grains
cooling rate- slower
cooling=larger crystals

Question 10

Types of textures theres 5

Answer 10

1 Course grains( phanertic )
Intrusive large crystals slow loss of heat ex granite
2 fine grained ( apathetic )
Many aphanitic rocks are extrusive grain cant be seen magna cools quickly
3 Porphyritic- large and small crystals
4 Glassy- few crystals cools fast- obsidian bubbly
5 vesicular- few crystals magma cools fast

Question 11

Compostion of rocks

Answer 11

1 felsic- magma or igneous rock that is rich in feldspar and silica
2 Mafic- rock rich in magnesium and irom
ultra mafic- composed of dark minerals
intermediate- lower proportions of silica.