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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
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Warm-up • How are the three main types of rock (igneous, sedimentary, and metamorphic rock) formed?
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
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. 5
Igneous Rocks Obsidian • Extrusive Igneous - rocks formed from cooled lava. Fine-grained, cooled quickly on the Earth’s surface. • Intrusive Igneous-rocks formed from cooled magma. Coarse-grained, cooled slowly beneath Earth’s surface. Granite
Texture- the “feel” of a rock due to the grain size, shape, and arrangement of mineral crystals or sediments in a rock Coarse texture Glassy Texture
Grain Size • Fine grained – individual mineral grains are too small to be seen without a microscope. • Coarse grained – can see individual grains.
Sedimentary Rocks How is Sedimentary Rock Formed? • Weathering • Erosion • Deposition • Burial • Lithification – sediments compact under pressure and gradually become solid rock
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
Clastic Sedimentary • 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
Chemical Sedimentary- sedimentary rocks formed from mineral pools after water has evaporated Halite Hematite
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
Metamorphic Rocks • Foliated Metamorphic- metamorphic rock with folds or bands • 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
Sediments Weathering/Erosion Deposition Compaction Cementation Uplift Uplift Uplift Igneous Rocks Sedimentary Rocks Crystallization Heat/Pressure Magma Heat/Pressure Melting Metamorphic 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 • Uniformitarianism: the processes we can observe today are the same processes that happened millions or billions of years ago • Waves crashing against the shore • Wind blowing sand eroding stone
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 • Of course, it may no longer be flat! • Original horizontality: sedimentary rocks are deposited in nearly horizontal or horizontal layers(just like your laundry)
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 Dating Radioactive decay- the process in which a radioactive isotope breaks down into a stable isotope of a different atom Radiometric dating- a method of determining age by estimating percentages of a radioactive (parent) isotope and a stable (daughter) isotope Half-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 0 Scientific Method/Nature of Science Branches of Earth Science Units and Measurement Latitude and Longitude Time Zones 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