Rock and Roll!A rock is a solid mixture of crystals of one or

more minerals.Uses:

Early humans used rock to make toolsBuildings (concrete)Science: helps us with the history of the Earth

Rock Types and MagmaIgneousSedimentaryMetamorphic

Magma is the hot liquid that forms when rock partially or completely melts.

The Rock CycleThe rock cycle is the process by which one

rock type changes into another.WeatheringErosionDepositionCompactingMetamorphismMeltingCoolingSolidification

Classifying RocksComposition – the minerals the rock is made

of.

Texture – sizes, shapes, and positions of the grains of which it is made.Fine grainedMedium-grainedCoarse-grained

Igneous RockWhen magma or lava cools down enough, it

solidifies to form igneous rock.Igneous means “fire” in Latin.

3 ways igneous rock can formheatPressure releasedComposition change

Igneous rock formationsIntrusive Igneous rock forms when magma

cools beneath the Earth’s surface.Usually coarse grained.Cools slowlyPlutons are large, balloon shaped intrusive

formations that result when magma cools slowly at great depths.

Igneous rock formationsExtrusive Igneous rocks form on the Earth’s

surface.Cools quicklyCan form from volcanoes or from fissures

(long cracks in the Earth’s surface)

Sedimentary RockThrough weathering and erosion, sediment

(rock fragments) is deposited in layers and becomes compacted.

Weathering, erosion, deposition, compaction

Layered rock – strataStratification – the layering of sedimentary

rock. (tells us a lot about history)

Sedimentary Rock compositonClastic – made of fragments of other rocks and

minerals. (ex. Sandstone)

Chemical – made of solutions of minerals and water. (ex. Chemical limestone)

Organic – made of remains of animals that once lived in the ocean. (limestone)Fossils are formed in sedimentary rock.

Metamorphic RockMeta means changed and morphos means

shape in Latin.

Rock undergoes metamorphism through heat or pressure or both.

All 3 types of rocks can change into metamorphic rock.

Types of MetamorphismContact: when a rock comes in contact with

magma.Regional: when enormous pressure builds up

in a rock that is deeply buried under other rock formations.

Textures of Metamorphic RockFoliated – has minerals that are aligned like

pages in a book.Nonfoliated – does not have a regular

pattern.Usually made of one or a few minerals.