Rocks

Bellringer

• K= know about rocks already• W= Want to learn about rocks• L= Learned about rocks

• Rocks are composed of 1 or more minerals

• There are 3 types of rocks: igneous, sedimentary, and metamorphic

• Rock cycle describes how the elements that make up rocks are redistributed transforming one rock into another

4 parts of Earth• Inner core: mass of iron 7000 degrees

Fahrenheit. Immense pressure keeps iron solid

• Outer core: mass of molten iron. Electric currents produce Earth’s magnetic field

• Mantle: slow moving molten rock or lava

• Crust: sand and rock

Composition of Magma

• Mix of molten rock, gases, and mineral crystals• Elements: O, Si, Al, Fe, Mg, Ca, K, Na• Compound most abundant: Silica• Silica content affects melting temperature

and impacts how quickly magma flows

Independent Work

• Make a Venn Diagram comparing and contrasting minerals and rocks

• Composition• Formation• Group• Elements Present

Bellringer

• Make a list of how you think rocks are used in everyday life

Magma Formation• Factors: temperature, pressure, water content,

and mineral composition.• Temperature increases with depth in Earth’s crust• Pressure increases with depth. Due to weight of

overlying rock• Small percentages of water are in rocks and

minerals. Water content increases, melting point decrease.

• Different minerals have different melting points.

Igneous Rock

• Forms from crystallization of magma (molten rock below Earth’s surface)

• 2 types of igneous rocks• Extrusive: fine grained, cools quickly

on Earth’s surface. Example: Rhyolite• Intrusive: coarse grained, cools slowly

beneath Earth’s surface. Example: Granite

Igneous Rock as a Resource

• Useful as building materials• Interlocking grain= strength• Minerals in igneous rocks are resistant

to weathering• Example: Granite• Ore deposits

Independent Work• 1. What are the 2 different types of igneous

rocks and describe how each forms?• 2. What are the factors that affect the

formation of magma?• 3. Why do you think magma is usually a

slushy mixture of crystals and rock. • 4. Make a Frayer model: 1. 4 parts of the

Earth. 2. How is magma formed. 3. Describe igneous rocks. 4. How can igneous rocks be used.

Bellringer

• Make a list of things you know about fossils

Sedimentary Rocks• Igneous rocks are the most common on Earth’s

crust• Do not see igneous rocks on the ground• Earth’s surface is covered in sediments• Sediments= pieces of solid material that have

been deposited on Earth’s surface by wind, water, ice, gravity, or chemical precipitation

• Sediments cement together to form sedimentary rocks.

• Formation begins with weathering and erosion.

Types of Sedimentary Rocks

• Clastic: Most common: Loose sediment: Varying sizes. Sandstone, shale• Chemical: Formed from

evaporation. Limestone, Rock salt• Organic: Remains of once living

things: Limestone, coal

Bellringer

• Referring to last week’s KWL, make a list of things you have learned about rocks so far under “L”

Importance of Sedimentary Rocks• Form fossils: provide information about past

animals and plants• Understand geologic change over time: flow of

rivers, wave/wind directions, shorelines• Sources of oil, natural gas, and coal• Uranium mined from sandstone: nuclear power• Limestone: cement for construction

Weathering• Weathering= physical and chemical

processes that break rock into smaller pieces• Chemical weathering=rocks are

dissolved or chemically changed• Physical weathering= minerals remain

chemically unchanged. Rock fragments break off along fractures.

Illustrate the Rock Cycle• Terms to be used: igneous, metamorphic,

sedimentary, magma, sediment, melting, heat, pressure, weathering, erosion, deposition, cementation, burial

• Do not simply use the terms, you need a picture to show the process. You can refer to your rock cycle worksheet.

Erosion and Transport• After rock fragments have been

weathered, they are transported to a new location• Erosion- movement of surface materials

from 1 location to another.• Agents of erosion= wind, moving water,

gravity, and glaciers• Examples: muddy water, dust, fine sand

Deposition• Deposition= sediments are laid down on the

ground or sink to bottom of bodies of water.• Sediment deposited when transport stops. • Fast-moving water can transport large

particles.• As water slows, largest particles settle, then

next-largest. Settles in layers• Wind moves small grains: Ex: sand dunes• Glaciers move all sizes easily: large boulders,

sand, mud

Metamorphic Rock• Heat and pressure form metamorphic rocks• Heat: derived from Earth’s internal heat• Pressure: derived from vertical pressure by

weight of overlying rocks or compressive forces

Independent Work• Make a concept Map with Rocks in the

middle.• From there, you need 3 legs for each of the

types of rocks• Make bubbles for how formed, how used,

examples, types.• Describe each further