Rocks Classifying Rocks Igneous Rocks Sedimentary Rocks Rocks from Reefs Metamorphic Rocks The Rock Cycle Table of Contents

Rocks

How Rocks Form Geologists classify rocks into three major groups: igneous rock, sedimentary rock, and metamorphic rock. - Classifying Rocks

Rocks Asking Questions Before you read, preview the red headings. In a graphic organizer like the one below, ask a what or how question for each heading. As you read, write answers to your questions. What does a rock’s color tell you? It can provide clues about the rock’s mineral and chemical composition. How do geologists describe a rock’s texture? Geologists use terms based on the size, shape, and patterns of the grains. QuestionAnswer - Classifying Rocks

Rocks End of Section: Classifying Rocks

Rocks

Mineral Mixture Granite is a mixture of light- colored minerals, such as feldspar and quartz, and dark- colored minerals, including hornblende and different types of mica. But granite can vary in mineral composition. This affects its color and texture. Study the circle graph and then answer the questions. - Igneous Rocks

Rocks Mineral Mixture Feldspar Reading Graphs: What mineral is most abundant in granite? - Igneous Rocks

Rocks

Classifying Igneous Rocks - Igneous Rocks Igneous rocks can be made from either lava and cool quickly (Extrusive) or magma (Intrusive) and cool slowly. They are then classified according to their origin, texture, and mineral composition. Label each as intrusive or extrusive

Rocks Mineral Mixture 10% Reading Graphs: About what percentage of granite is made up of dark minerals? - Igneous Rocks

Rocks Mineral Mixture 100% - (35% + 10%) = 55% Calculating: If the amount of quartz increases to 35 percent and the amount of dark-colored minerals stays the same, what percentage of the granite will be made up of feldspar? - Igneous Rocks

Rocks Mineral Mixture The overall color would be darker. Predicting: How would the color of the granite change if it contained less feldspar and more mica and hornblende? - Igneous Rocks

Rocks Detail Main Idea As you read the section “Classifying Igneous Rocks,” write the main idea in a graphic organizer like the one below. Then write three supporting details. The supporting details further explain the main idea. Igneous rocks are classified by origin, texture, and composition. Extrusive rock forms from lava on the surface; intrusive rock forms from magma from beneath the surface. Intrusive rocks have larger crystals than extrusive rocks because they cool more slowly. High-silica rocks are light colored; low- silica rocks are dark colored. - Igneous Rocks Identifying Main Ideas

Rocks End of Section: Igneous Rocks

Rocks

From Sediment to Rock Most sedimentary rocks are formed through a series of processes: Weathering, erosion, deposition, compaction, and cementation. (Cementation is also known as Lithification ) - Sedimentary Rocks Weathering – breaking down of rocks to make sediment. Often times this happens due to weather

Rocks

Metamorphic Rocks Metamorphic rocks come from the transformation of any existing rock types, The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure (1500 bars),[1] causing physical and/or chemical changes. The beginning rock may be sedimentary rock, igneous rock or another older metamorphic rock (but it does not melt completely).

Rocks Outlining Lithification - Another word for Cementation (the gluing together of clastic pieces with deposited minerals) in sedimentary rocks. Sedimentary Rocks I.From Sediment to Rock A.Erosion B.Deposition C.Compaction D.Cementation II.Types of Sedimentary Rock A.Clastic Rocks B.Organic Rocks C.Chemical Rocks III.Uses of Sedimentary Rocks A.Building Materials B.Tools - Sedimentary Rocks

Rocks

What You Know What You Learned Using Prior Knowledge Before you read, look at the section headings and visuals to see what this section is about. Then write what you know about coral reefs in a graphic organizer like the one below. As you read, write what you learn. 1.Coral reefs grow in the oceans. 2.Florida has coral reefs. 3.Oceans used to be where there is dry land now. 1.Coral animals cannot live below 40 meters. 2.In the United States, only the coasts of Florida and Hawaii have coral reefs. 3.Some limestone deposits on land formed from ancient reefs. - Rocks From Reefs

Rocks Previewing Visuals Before you read, preview Figure 17. Then write two questions that you have about metamorphic rocks in a graphic organizer like the one below. As you read, answer your questions. Previewing Q. Why do the crystals in gneiss line up in bands? A. Gneiss is a type of metamorphic rock that is foliated—the crystals are flattened to form parallel lines. Q. How does quartzite form from sandstone? A. High temperature and pressure on the minerals in sandstone cause them to be changed into minerals that make up quartzite. - Metamorphic Rocks

Rocks A Cycle of Many Pathways Forces deep inside Earth and at the surface produce a slow cycle that builds, destroys, and changes the rocks in the crust. - The Rock Cycle

Rocks

Sequencing As you read, make a cycle diagram that shows stages in the rock cycle. Write each stage of the rock cycle in a separate circle in your diagram. Igneous Sedimentary Metamorphic - The Rock Cycle

Rocks End of Section: The Rock Cycle

Rocks Graphic Organizer Igneous Metamorphic Extrusive Organic Chemical Foliated

Rocks End of Section: Graphic Organizer