The Rock Cycle ROCKS D 1 Rocks in

The Rock Cycle ROCKS : -D 1

Rocks in the earth are constantly changing. n Composition n Shape n 2

What exactly is rock? A solid mixture of crystals of one or more minerals, that range in all sizes (from pebbles to formations that are thousands of kilometers long). 3

The Value of Rock Important natural resource. n Early humans made tools such as hammers, spears, knives, and scrapers. n Buildings, roads, and monuments. n Certain types of rocks have helped build ancient and modern civilizations. Concrete. n 4

Some Uses of Rocks 1. 2. 3. 4. 5. 6. 7. Tools (Scalpels) Buildings Utensils Roads Monuments Provide clues to the past – history of the Earth (fossils) and the Universe (meteors) Scientists study rocks from other planets 5

Machu Picchu, Peru 600 A. D. Ancient Civilization Rock Structure 6

The Rock Cycle n n a) b) c) is the process by which one type of rock changes into another There are 3 types of rock: Sedimentary Metamorphic Igneous 7

The Rock Cycle 8

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List the Processes that affect Rocks Melting and Cooling 2. Heat and Pressure 3. Weathering and Erosion, Deposition 4. Compaction and Cementation, or Lithification 5. Uplift and Subsidence 1. 10

How are Rocks Classified? 1. By Composition – What minerals are present in the rock? For e. g. Granite may contain 10% Biotite, 35% Quartz, 55% Feldspar By Texture. - Texture is determined by sizes, shapes and positions of grains it is made of: « Fine-grained: e. g. silt, clay, siltstone « Coarse-grained: e. g. large pebbles, conglomerate « Medium-grained- inbetween, e. g. granite, sandstone 11

Answer these Qus. in your ntbk 1. 2. 3. 4. List 2 ways rock is important to us today What are three major Rock types, and how can they be changed from one type to another? How is lava different from magma? Comparing Concepts. Explain the difference between texture and composition. 12

Three Types of Rock Igneous Rock n. Sedimentary Rock n. Metamorphic Rock n 13

Sedimentary rocks n n Made up of sediments eroded from igneous, metamorphic, other sedimentary rocks, and even the remains of dead plants and animals. Sediments are deposited in layers, or strata, and then are squeezed/compressed/compacted into rock. Most fossils are found in sedimentary rocks. Examples: Sandstone, Shale, Conglomerate Limestone, Chert, Coal, Gypsum, Halite 14

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The City of Petra 16

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Fossils in sedimentary rock 19

Igneous Rocks n n Molten material such as magma (within the Earth) or lava (on the surface) cools and hardens. The hot material crystallizes into different minerals. The properties and sizes of the various crystals depend on the magma's composition and its rate of cooling. Examples: Granite, Obsidian, Basalt, Pumice, Andesite , Diorite, Rhyolite 20

Igneous coarse grained 21

Igneous glassy texture 22

Igneous Porphyritic texture 23

Igneous Fine-grained 24

Metamorphic Rock Produced when sedimentary or igneous rocks are transformed by heat and/or pressure. n The word "metamorphic" comes from the Greek language, which means "to change form. “ n Example: Marble, Slate, Quartzite, Schist , Gneiss n 25

Gneiss Schist Amphibolite Quartzite 26

Analogy of granite and ice-cream http: //uts. cc. utexas. edu/~rmr/analogy. html n An Interactive Rock Identification Key http: //www. rockhounds. com/rockshop/rockkey/#Key n Rock Identification made easy n An animated view of the events in the rock cycle http: //www. classzone. com/books/earth_science/terc/c ontent/investigations/es 0602 page 02. cfm? cha pter_no=investigation n http: //www. classzone. com/books/earth_science/terc/c ontent/investigations/es 0602 page 02. cfm n n http: //www. beyondbooks. com/ear 82/7. asp 27

Real Life n n n I, Rock Write a story from the point of view of a rock that moves through the rock cycle. Choose any type of rock: igneous, sedimentary, metamorphic, to start. Explain the rock cycle from formation to decomposition. Write your story as if you were the rock. Imagine you are at the end of the your cycle and tell your life story. Explain what kind of rock you are, how you were formed, and what your journey has been like. Give your rock a name and personality. Your story should include your location and age at various stages of development. If you have been in contact with humans, explain the effects they have had on you and your interaction with them. Have humans used you to answer their questions about the earth? Conclude your story with your predictions for changes in the earth's surface as you decompose. 28 Sympathize with the audience’s situation, if appropriate!