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