WARM-UP #21 FEB. 9

The western part of California is located on a boundary between two tectonic plates. Would most of the metamorphic rock in that occur in small patches or wide regions? How do you know?

Chapter 3

ROCKS

ROCKS A rock is any solid mass of mineral or

mineral-like matter that occurs naturally as part of our planet.

There are 3 major type: Igneous Sedimentary Metamorphic

THE ROCK CYCLE Shows the relationship among the

three rock types . Proposed by James Hutton in the late

1700s. Interactions among Earth’s water, air,

land, and living things can cause rocks to change from one form to another

The continuous processes that cause rock to change make up the rock cycle

THE ROCK CYCLE Magma – molten material that forms

deep beneath Earth’s surface Cools and hardens as the result of volcanic

eruption Igneous rocks form

Undergo weathering form Sedimentary rocks

Sedimentary rocks in time morph into metamorphic rocks

WEATHERING Process in which rocks are physically

and chemically broken down What types of things do this?

Water Air Living things

Weathered materials are called sediments

ROCK CYCLE The full rock cycle doesn’t always have

to happen. Sedimentary rock can melt. Igneous rock can morph. Sedimentary and Metamorphic rocks

can be weathered.

DOES THAT ROCK HAVE A FUTURE? http://www.sascurriculumpathways.com Login, quick launch # is 71 Read the introduction pages Reseach and respond to the questions

provided. Do this on a separate sheet of paper

WARM-UP #19 FEB. 7

Texture Coarse-grained Fine-grained Glassy Porphyritic

Composition Granitic Basaltic Andesitic

Texture and composition are two characteristics used to classify igneous rock

ROCKS Rocks are considered the building

blocks of the Earth

Rock is defined as a group of minerals bound together in some way

There are three types

TYPES Igneous

Metamorphic

Sedimentary

IGNEOUS Igneous rocks form from

magma

Magma comes in different types Felsic Mafic

There are 2 types of igneous rocks Intrusive Extrusive

FELSIC MAGMA High in silicates Light in color Typically forms at the top of a

magma chamber

MAFIC MAGMA Low in silicates Higher in magnesium and iron Dark colored Typically forms at the bottom of the

magma chamber

INTRUSIVE Form underneath the Earth’s surface as

magma cools and solidifies These rocks tend to have visible

mineral crystals because of the slow cooling

COMMON INTRUSIVE IGNEOUS ROCKS Granite

Diorite

Rhyolite

EXTRUSIVE IGNEOUS ROCKS Forms outside Earth’s crust Cools quickly Very few mineral crystals are visible

COMMON EXTRUSIVE ROCKS Obsidian

Pumice

Basalt

DICHOTOMOUS KEY FOR IGNEOUS ROCKS

Are your rock grains sand-sized or smaller?

No

No

No

No

Does your rock contain quartz?

Is your rock mostly dark colored?

Granite

Does your rock look like black glass?

Will your rock float on water?

Does your rock contain quartz?

No

No

Yes

Yes

Yes

Yes

Yes

Yes

Gabbro

Diorite

Obsidian

Basalt

Rhyolite Andesite

WARM-UP #20 FEB. 8 How do igneous, sedimentary, and

metamorphic rocks differ?

What powers Earth’s rock cycle?

SEDIMENTARY ROCKS All sedimentary rocks start as small

pieces called sediment Sediment is then compacted and

cemented into rocks

FORMATION Weathering is usually the first step in

the formation Chemical weathering takes place

when minerals in rocks change into new substances

Physical weathering takes place when minerals or rocks just break into smaller pieces

FORMATION Sediment doesn’t usually stay in one

place It is moved by water, wind, ice, gravity Erosion – weathering and removal When the agent of erosion loses power

or energy, it drops the sediment

FORMATION Compaction – process that squeezes

sediments Cementation takes place when

dissolved minerals are deposited in the tiny spaces among sediments

CLASSIFICATION Two main categories

Clastic Chemical

CLASTIC Made by weathered bits of rocks and

minerals Then grouped by size of the sediment

Conglomerate – large rounded particles Breccia – angular pieces Sandstone – pieces the size of sand Shale – very fine-grained sediment Siltstone – another fine-grained category

CHEMICAL Formed when dissolved minerals

precipitate from water solutions Limestone

METAMORPHIC ROCKS Formed when rocks and minerals

undergo changes caused by heat, pressure and chemical fluids.

METAMORPHISM Contact metamorphism

Hot magma moves into rocks Brings minor changes Marble often forms from this

Regional metamorphism Large-scale deformation and high-grade

metamorphism May occur during mountain building

AGENTS OF METAMORPHISM Heat – MOST IMPORTANT

Provides energy to drive a reaction Comes from magma and change in temp.

with depth Pressure – increases with depth

Cause rock to flow Hydrothermal solutions

CLASSIFICATION - TEXTURE Foliated

More compact More dense

Nonfoliated Doesn’t have a banded texture Contains only one mineral

http://www.learner.org/interactives/rockcycle/

TICKET OUT THE DOOR

1. Draw a quick sketch of the rock cycle.

2. What types of things cause weathering and erosion