2. Rocks & Minerals

• Igneous Rock

• Sedimentary Rock

• Metamorphic Rock

Three Different Kinds of Rocks

Igneous Rock

It forms when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust.

• Intrusive (Plutonic)

• Extrusive (Volcanic)

Types of Igneous Rock

Intrusive (Plutonic)

It is when magma hardens deep inside the crust.

Extrusive (Volcanic)

It is when magma solidifies at the surface.

Composition & Texture

Igneous Rocks can be classified by these two.

Composition

Elements in the magma that affect the kind of mineral that is formed.

Mafic Rock

It is formed from magma during crustal spreading.

Felsic Rock

It is formed from magma during the crustal subduction.

Texture

It is the general appearance of the rock due to the presence of crystals. The size of the crystal is directly related to the rate of cooling.

Phaneritic

These are rocks with coarse crystals.

Aphanatic

These are rocks with fine crystals.

Sedimentary Rock

It is formed through lithification.

Lithification

It is the process of cementing soft, unconsolidated sediments to form a rock.

Deposition, Compaction, Cementation, Sedimentation

Process of Lithification

Stratification

It is the layering of sediments. Each layer represents a different and separate depositional activity and timing.

Classic, Chemical, Organic

Types of Sedimentary Rocks

Classic

Sedimentary rocks that went through the "classic" process, which is the lithification process.

Chemical

Sediments that were dissolved in water precipitate (separating the liquid part) when they reach saturation.

Organic

Rocks that are formed from sediments and debris brought by these processes (waste products, decomposition)

Metamorphic Rock

It is a rock from an original form (igneous, sedimentary, or another metamorphic) that went through metamorphism.

Metamorphism

It is a process of changing or transforming a kind of rock into a new rock.

Regional & Contact

Types of Metamorphic Rock

Regional

It is the change or process brought by pressure (faulting, mountain formation) deep within the Earth

Contact

This process occurs when rock found in the intrusion is heated.