Rock CycleHomework: Read 75-85

Do Cornell notes (key terms and Vocab)

Bell Ringer quiz:1. What is a mineral?

2. What is a rock?3. What powers the Earth’s

rock cycle?4. How do fine grained igneous

rocks form?

Rocks A rock is any solid mass of mineral or

mineral-like matter that occurs naturally as part of our planet. • Some rocks are a single mineral, but most rocks are

combinations of minerals.

Rocks are classified into three major groups:1. Igneous2. Sedimentary3. Metamorphic

Rocks Igneous rock is formed by the

crystallization of molten magma. Sedimentary rock is formed from the

weathered products of rocks that have been transported, deposited, compacted, and cemented.

Metamorphic rock is formed by the alteration of pre-existing rock deep within Earth (but still in the solid state) by heat, pressure, and/or chemically active fluids.

Rock Cycle Interactions among Earth’s water, air,

and land can cause rocks to change from one type to another. This continuous process is called the rock cycle.

Shows the interrelationships among the three rock types

Rock Cycle Magma is molten material that

forms deep beneath the Earth’s surface.• When magma cools and hardens beneath

the surface or from volcanic eruptions, igneous rocks form.

• Lava is magma that reaches the surface. Weathering is a process in which

rocks are physically and chemically broken down by water, air, and living things.

Continued Sediment is weathered pieces of

Earth elements. Eventually sediments are compacted

and cemented to form sedimentary rocks.

If the sedimentary rocks get buried deep under the Earth it would be subjected to extreme temperature and pressure. It will then change into metamorphic rocks.

Power for the Rock Cycle Processes driven by heat from the

Earth’s interior are responsible for forming both igneous rock and metamorphic rock.

Weathering and the movement of weathered materials are external processes powered by energy from the sun.

External processes produce sedimentary rocks.

Continued Journey through the Rock Cycle. How might a sedimentary rock become an

igneous rock?• The rock could become buried at depths where

temperatures and pressures were great enough to cause melting. When the melted material (magma) cooled and hardened, an igneous rock would form.

What processes change sedimentary rock into another sedimentary rock?• Weathering, transportation, deposition, compaction,

and cementation

Igneous Rocks Fire! Intrusive igneous rocks are formed

when magma hardens beneath Earth’s surface.• Erosion exposes these rocks.• Magma has many elements and gases. As magma

rises, it cools allowing elements to bond and form minerals,

• Granite is a common intrusive igneous rock. Extrusive igneous rocks are formed

when lava hardens.

Classification Classified by texture and compositionTexture

1. Coarse-grained texture is caused by slow cooling resulting in larger crystals.

2. Fine-grained texture is caused by rapid cooling resulting in smaller, interconnected mineral grains.

3. Glassy texture is caused by very rapid cooling. 4. Porphyritic texture is caused by different

rates of cooling resulting in varied sized minerals.

ClassificationComposition1. Granitic composition rocks are made mostly

of light-colored quartz and feldspar.2. Basaltic composition rocks are made mostly

of dark-colored silicate minerals and plagioclase feldspar.

3. Andesitic composition rocks are between granitic light-color minerals and basaltic composition dark-colored minerals.

4. Ultramafic composition rocks are made mostly from iron and magnesium-rich minerals.