Types of Rocks

IGNEOUS ROCKS

comprises 95% of the Earth’s crust

How do igneous rocks form?

Magma - Solidification of Lava - Igneous Rocks

Intrusive Igneous Rocks (PLUTONIC)

Magma cools down and solidifies inside the earth’s surface.

Slow cooling

Large crystals

Extrusive Igneous Rocks (VOLCANIC)

Magma cools down and solidifies above the Earth’s surface

Fast cooling

small crystals

SEDIMENTARY ROCKS

Comprised of Sediments

How do Sedimentary rocks form?

thru lithification process

Lithification:

a complex process whereby freshly deposited loose grains of sediment are converted into rock.

Compaction:

Reduces pore space due to the weight of sediments above.

Cementation:

Dissolved substances precipitate out and act as glue.

Recrystallization:

Form new crystalline mineral grains from the old ones

Diagenesis:

the cycle repeats.

CLASTIC ROCKS:

formed when individual sediment made by fragments of rocks, minerals, or shells are cemented together.

CRYSTALLINE ROCKS

formed by the crystallization of chemical precipitates.

BIOCLASTIC ROCKS:

Formed mostly by the remains of organisms.

METAMORPHIC ROCKS

exposed to high temperature and pressure.

FOLIATED METAMORPHIC ROCKS:

produced by exposure to heat and directed pressure.

NON-FOLIATED METAMORPHIC ROCKS

temperatures are high but the pressures are relatively slow.