Igneous rocks

According to the rock cycle, what are the two processes required to make an igneous rock?

cooling and solidification of magma or lava

Lava

molten rock that has reached Earth’s surface.

Magma

molten rock located beneath Earth’s surface

difference in crystal size between intrusive igneous rocks and extrusive igneous rocks.

Intrusive igneous rocks have large crystals because they cool slowly underground, extrusive igneous rocks have small or glassy crystals because they cool quickly at Earth’s surface.

difference in color between mafic and felsic igneous rocks.

Mafic igneous rocks are dark-colored, felsic igneous rocks are light-colored.

density of an average mafic igneous rock to the density of an average felsic igneous rock.

An average mafic igneous rock is denser than an average felsic igneous rock.

five minerals that are present in the average sample of granite.

quartz, potassium feldspar, plagioclase feldspar, biotite, and amphibole

“plutonic”

Plutonic igneous rocks form beneath Earth’s surface and intrusive

Volcanic

volcanic igneous rocks form at Earth’s surface and are extrusive.

what does “rich in Si, Al” under the word felsic indicate?

felsic rocks have a high silica and aluminum content, making them light-colored and less dense.

what does “rich in Fe, Mg” under the word mafic indicate?

mafic rocks have a high iron and magnesium content, making them dark-colored and dense.

does the igneous rock diorite form slowly or quickly, and explain how you can tell by looking at the rock.

diorite forms slowly because it is coarse-grained, meaning it has large, visible crystals.

Name the coarse-grained igneous rock composed of 25% plagioclase feldspar, 65% pyroxene, 6% olivine, and 4% amphibole.

Gabbro

what is the texture of andesite?

Fine-grained

The form of energy that creates magma and lava can also be used to produce heat and hot water. This form of energy is abundantly available in certain areas such as northern California and Iceland. The form of energy described is one alternative to using fossil fuels such as coal, oil, and natural gas. Name the source of energy described.

Geothermal energy

The ocean basins or the sea floor (the oceanic crust) is composed primarily of what igneous rock?

Basalt

The continents (the continental crustal plates) are composed primarily of what igneous rock?

Granite