Warm-up• How are the three main types

of rock (igneous, sedimentary, and metamorphic rock) formed?

1. List the rock layers from oldest to youngest

Unit 1 Test

• 40 multiple choice questions, 1 honor’s short answer question

• Chapters 5, 6, and 21• Types of rocks and how they are formed• The Rock Cycle• Geologic Time (Relative and Absolute Dating)• Review of topics from unit 0

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Types of Rocks• Igneous– form from

solidification of molten (liquid) rock material.

• Sedimentary– form from compaction and cementation of sediments

• Metamorphic– form from recrystallization of existing rock material.

•Intrusive Igneous-rocks formed from cooled magma. Coarse-grained, cooled slowly beneath Earth’s surface.

• Extrusive Igneous - rocks formed from cooled lava. Fine-grained, cooled quickly on the Earth’s surface.

Obsidian

Granite

Igneous Rocks

• Texture- the “feel” of a rock due to the grain size, shape, and arrangement of mineral crystals or sediments in a rock

Coarse textureGlassy Texture

• Grain Size

» Fine grained – individual mineral grains are too small to be seen without a microscope.

Coarse grained – can see individual grains.

How is Sedimentary Rock Formed?

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• Weathering• Erosion• Deposition• Burial• Lithification – sediments

compact under pressure and gradually become solid rock

Sedimentary Rocks

3 Main Classes of Sedimentary Rocks

• Clastic – formed from clastic sediments

• Chemical – formed from minerals precipitated from water

• Organic – formed from the remains of once-living things

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• sedimentary rocks formed from layers

• Clast refers to a fragment of rock that was broken from a larger rock

• Clastic rocks are composed of these clasts.

Conglomerate

Clastic Sedimentary

• Chemical Sedimentary- sedimentary rocks formed from mineral pools after water has evaporated

HaliteHematite

• Organic Sedimentary- sedimentary rocks formed from the remains of once-living things.

Coal

Metamorphic RocksMetamorphism

• High temperature and pressure without melting. Changes form while remaining solid.– Earth’s internal heat => high temperature– Weight of overlying rock => high pressure– Compressive forces => high pressure

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• Foliated Metamorphic- metamorphic rock with folds or bands

Metamorphic Rocks

• Nonfoliated Metamorphic- metamorphic rock without folds or bands

• Contact Metamorphism- metamorphism from contact with magma

• Regional Metamorphism- metamorphism from pressure of the Earth’s Crust

Create a Flow Chart using the following terms:

Crystallization (cooling and hardening) Igneous rocks Metamorphic rocks Sedimentary rocks Sediments Melting Heat/Pressure (2 times) Weathering/Erosion Deposition/Compaction/Cementation Uplift (3 times) Magma

Igneous Rocks

Heat/Pressure

Heat/Pressure

Weathering/Erosion

Metamorphic Rocks

Sedimentary Rocks

Sediments

Uplift

Melting

Uplift

Uplift

Deposition Compaction Cementation

Magma

Crystallization

Dating of Rocks

Age• Relative age: establishes order

from youngest to oldest, but does not give exact time frames

• Absolute age: establishes the date of an event

Relative Dating• By application of a set of geological “rules”

– Uniformitarianism– Superposition– Original Horizontality– Cross-cutting Relationships– Inclusions

Uniformitarianism

• Waves crashing against the shore

• Wind blowing sand eroding stone

• Uniformitarianism: the processes we can observe today are the same processes that happened millions or billions of years ago

Superposition• For an undisturbed rock sequence, the oldest

rocks are at the bottom and each successive layer is younger than the layer beneath

Original Horizontality• Original horizontality: sedimentary rocks are

deposited in nearly horizontal or horizontal layers(just like your laundry)

• Of course, it may no longer be flat!

Cross-cutting Relationships• Cross-cutting

relationships: an intrusion or fault is younger than the rock it cuts through – You have to bake the

cake before you can cut through it, right?

Cross-Cutting Relationships Which is older? Which is younger? Why?

Absolute DatingRadioactive decay- the process in which a radioactive isotope breaks down into a stable isotope of a different atomRadiometric dating- a method of determining age by estimating percentages of a radioactive (parent) isotope and a stable (daughter) isotopeHalf-life- the time needed for half of a sample of a radioactive substance to decay

Don’t Forget!!!!!• You are responsible for all information

that we have covered this year.• You should be prepared to answer

questions from the last unit as well.• Review the test review powerpoint

from unit 0 on the assignments/homework page.

Main Topics from Unit 01. Scientific Method/Nature of Science2. Branches of Earth Science3. Units and Measurement4. Latitude and Longitude5. Time Zones6. Maps and Topographic Maps

Units and Measurement• Understand length, area, volume,

mass, density, temperature• Know the SI units for each• Unit conversions (1kg = ?mg)• Know the ladder!!!!! (and how to

use the ladder method)

Units and Measurement• Know the ladder and how to use it!

Maps/Topographic Maps• Interpret a legend• Interpret a topographic map• Components of a map (what

things that every map must have?)

• Contour lines, contour intervals, index contours, hachures