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How to Use This Presentation • To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show”, or simply press F 5 on the top row of your keyboard. • To advance to the next slide click the left mouse button once. • From the Chapter screen you can click on any section to go directly to that section’s presentation. • Blank or “missing” areas of a slide will remain hidden until the left mouse button is clicked. • You may exit the slide show at any time by pressing the Esc key Copyright © by Holt, Rinehart and Winston. All rights reserved.

Module F: Chapter 2 Rocks: Mineral Mixtures Section 1: The Rock Cycle Section 2: Igneous Rock Section 3: Sedimentary Rock Section 4: Metamorphic Rock End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 1 The Rock Cycle Bellringer Most of us work hard to recycle the items we use in our daily life lives to minimize the pollution we cause. In a way the earth also recycles, through the rock cycle. Can you imagine what rock might look like through each stage of the rock cycle? How long do you think it takes to recycle a soda can? What about a piece of granite? Record your thoughts in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 1 The Rock Cycle Objectives • Describe two ways rocks have been used by humans. • Describe four processes that shape Earth’s features. • Describe how each type of rock changes into another type as it moves through the rock cycle. • List two characteristics of rock that are used to help classify it. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 1 The Rock Cycle The Value of Rock • What Is Rock? Scientists define rock as a naturally occurring solid mixture of crystals of one or more minerals. • Why Is Rock Important? Rock has been an important natural resource for as long as humans have existed. Early humans used rock to make tools. Ancient and modern civilizations have used rock as a construction material. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 1 The Rock Cycle Processes That Shape the Earth • Weathering, Erosion, and Deposition Weathering, erosion, and deposition are all processes that shape the surface of the Earth. • Heat and Pressure Sedimentary rock can form when buried sediment is squeezed by the weight of overlying layers of sediment. If the temperature and pressure are high enough, the rock can change into metamorphic rock. • How the Cycle Continues Buried rock is exposed at the Earth’s surface by a combination of uplift and erosion. This continues the rock cycle. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 1 The Rock Cycle Illustrating the Rock Cycle • The Flow of Rock The rock cycle is the continual process by which new rock forms from old rock material. Round and Round It Goes • Rolling Stones The sequence of events in the rock cycle depends on processes, such as weathering, erosion, deposition, pressure, and heat, that change the rock material. Look at the illustrated rock cycle on the next slide and identify what processes are taking place at each stage. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 1 The Rock Cycle Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 1 The Rock Cycle Rock Classification • Composition The composition of a rock is determined by the minerals that make up the rock. • Texture The texture of a rock is determined by the size, shape, and positions of the grains that make up the rock. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 2 Igneous Rock Bellringer Do you think rocks that cooled and solidified from lava on Earth’s surface would look different from those that cooled and solidified from magma inside the Earth? Would you be more likely to find igneous rock in the Rocky Mountains or in the Hawaiian Islands? Explain your answer in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 2 Igneous Rock Objectives • Describe three ways that igneous rock forms. • Explain how the cooling rate of magma affects the texture of igneous rock. • Distinguish between igneous rock that cools within Earth’s crust and igneous rock that cools at Earth’s surface. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 2 Igneous Rock Origins of Igneous Rock • Formation Igneous rock forms when magma cools and hardens. Composition and Texture of Igneous Rock • Appearance Determined by Cooling Rate Igneous rocks can be composed of a wide variety of minerals. The texture of igneous rock is determined by the rate at which the rock cools. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 2 Igneous Rock Formations • Intrusive Igneous Rock When magma intrudes, or pushes, into surrounding rock below the Earth’s surface and cools, the rock that forms is called intrusive igneous rock. Intrusive igneous rock usually has a coarse-grained texture because it is well insulated by surrounding rock and cools very slowly. Some intrusive igneous formations are illustrated on the next slide. • Extrusive Igneous Rock Igneous rock that forms from magma that erupts, or extrudes, onto the Earth’s surface is called extrusive igneous rock. Extrusive rock is common End of Slide around volcanoes. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 2 Intrusive Igneous Rock Bodies Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 3 Sedimentary Rock Bellringer Tree rings are formed each year of a trees life cycle. Tree rings exist because the weather changes of the seasons are reflected in the trees bark as the tree grows. Sedimentary rock is formed in layers over time much the same way. Events like forest fires and droughts will be visible in tree rings just as they are visible in sedimentary rock layers. How are layers in sedimentary rock alike or different from rings in a tree? What can geologists infer from examining sedimentary rock layers? Record your answers in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 3 Sedimentary Rock Objectives • Describe the origin of sedimentary rock. • Describe three main categories of sedimentary rock. • Describe three types of sedimentary structures. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 3 Sedimentary Rock Origins of Sedimentary Rock • How Sedimentary Rock Is Formed Through the process of erosion, rock and mineral fragments, called sediment, are moved from one place to another. Eventually, the sediment is deposited in layers. The layers develop into a natural cement that binds the rock and mineral fragments together into sedimentary rock. • Where Sedimentary Rock Is Formed Sedimentary rock forms at or near the Earth’s surface. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 3 Sedimentary Rock Composition of Sedimentary Rock • Clastic Sedimentary Rock Clastic sedimentary rock forms when rock or mineral fragments are cemented together. • Chemical Sedimentary Rock Chemical sedimentary rock forms from solutions of dissolved minerals and water. • Organic Sedimentary Rock Organic limestone forms from the remains of plants and animals. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 3 Sedimentary Rock Structures • Common Structures Sedimentary structures include ripple marks, mud cracks, and rain-drop impressions. • Stratification The most important feature of sedimentary rock is stratification. Stratification is the process in which sedimentary rocks are arranged in layers. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 4 Metamorphic Rock Bellringer Write a brief description of how cookies are made. How is the mixture of raw ingredients like sedimentary rock? Do the raw ingredients of a cookie look the same after they are done baking? Describe how cookie dough metamorphoses when it is baked in an oven. Record your responses in your science journal. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 4 Metamorphic Rock Objectives • Describe two ways a rock can undergo metamorphism. • Explain how the mineral composition of rocks changes as the rocks undergo metamorphism. • Describe the difference between foliated and nonfoliated metamorphic rock. • Explain how metamorphic rock structures are related to deformation. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 4 Metamorphic Rock Origins of Metamorphic Rock • Contact Metamorphism One way rock can undergo metamorphism is by being heated by nearby magma. When magma moves through the crust, the magma heats the surrounding rock and changes it, causing contact metamorphism. • Regional Metamorphism When pressure builds up in rock that is buried deep below other rock formations or when large pieces of the Earth’s crust collide with each other, regional metamorphism occurs. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 4 Regional and Contact Metamorphism Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 4 Metamorphic Rock Composition of Metamorphic Rock • Changes in Composition As rocks undergo metamorphism, the original minerals in a rock change into new minerals that are more stable in new pressure and temperature conditions. • Index Minerals Many of these new minerals form only in metamorphic rock. These minerals are known as index minerals, and are used to estimate the temperature, depth, and pressure at which a rock undergoes metamorphism. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Section 4 Metamorphic Rock Textures of Metamorphic Rock • Foliated Metamorphic Rock Foliated metamorphic rock has mineral crystals aligned in planes or bands. • Nonfoliated Metamorphic Rock Nonfoliated rocks have unaligned mineral crystals. Metamorphic Rock Structures • Deformation Metamorphic rock structures are caused by deformation. End of Slide Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 4 Rocks: Mineral Mixtures Concept Map Use the following terms to complete the concept map on the next slide: clastic, exclusive, igneous, intrusive, metamorphic, regional, rocks, sedimentary. Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 4 Concept Map Copyright © by Holt, Rinehart and Winston. All rights reserved.

Chapter 4 Concept Map Copyright © by Holt, Rinehart and Winston. All rights reserved.