Thai Christian School Grade 6 English Program SCIENCE Home Study Name : Number :... Subject : Science Grade : 6/ Teacher : Miss Maggie Quinn Date : November 2011 Parent Signature:... Instructions: Read and answer the questions. Chapter 4: Rocks and Their Transformations The rocks around us may be thousands or millions of years old. There are many types of rocks. They come in various colors, hardness, and textures. The rocks you see around you the mountains and riverbeds, are all made of minerals. A rock may consist of two or more minerals. Minerals: are made of chemicals, either a single chemical or a few. All rocks are made of minerals. Diamonds, quartz, feldspar and mica are examples of minerals found in rocks. Minerals in rocks are like the ingredients in a cookie. The cookie is the rock. The flour, butter, chocolate and sugar are like the minerals that make up the rock. Questions: Write True or False 1. The rocks around us are hundreds of years old. 2. There are many types of rocks with different colors, hardness, and texture. 3. Rocks are made up of one or more minerals. 4. Rocks are made up of minerals, just like a chocolate chip cookie is made up of flour, butter, chocolate and sugar. The Three Types of Rocks Rocks can be put into three main groups based on the way they are formed. I. Igneous Rocks II. Sedimentary Rocks III. Metamorphic Rocks Created by magma and lava. Created by compressed layers of sediment. Created from other rocks by heat and pressure.
I. Igneous rocks: Igneous means fire in Greek. Igneous rocks are formed when magma cools and solidifies. Magma is extremely hot liquid molten rock found deep in the Earth. Magma can be 700-1300 degrees Celsius. Once magma reaches the surface of the Earth it is called lava. Magma usually comes out of the Earth as lava through volcanoes. There are two types of igneous rocks. Intrusive and extrusive. Look at the differences and similarities of these rocks. Extrusive Rock Intrusive Rock All Igneous Rocks Intrusive Rocks Both Extrusive Rocks Created when magma cools slowly underground and solidifies into large crystals. Example: Granite, very hard, solid rock, many mountains are made of granite. Doi Inthanon in Chaingmai is a granite mountain Questions: Complete the sentences. Created by magma Do not have fossils because they are made of molten rock Created by volcanoes from lava. Lava cools quickly and forms rocks with small crystals. Example. Obsidian (looks like black glass because it cooled very quickly) basalt, pumice, have holes, light. Basalt can be found in the Phetchabun mountains 1. Igneous rocks (a) is liquid rock found deep inside Earth. 2. Magma (b) are made of magma and have large crystals. 3. Lava (c) are made of lava and have small crystals. 4. Intrusive igneous rocks (d) are formed when magma cools and solidifies. 5. Extrusive igneous rocks (e) comes out of volcanoes.
II. Sedimentary rocks Sedimentary rocks are created by layers and layers of sediments. Sediments - are the bits and pieces of rocks that have been broken down by time, wind and water. These small pieces of rock are washed into rivers, seas, and oceans and settle at the bottom of the water. Often minerals and dead living things are also found in the sediments. Over millions of years, layers after layers of sediments pile up and are compressed by gravity, air and water pressure. The sediments loose water over time and they slowly harden and become rocks. Most sedimentary rocks are formed in water. Different rocks are made up of different sediments. Limestone is mostly made up of shells or skeletons of marine animals like corals and shellfish Conglomerate is made of pebbles and sand Sandstone made of sand, is usually layered Shale or mudstone, is made up of clay or mud Gypsum made up of sulphate minerals, formed by evaporating sea water Sedimentary rocks usually look layered. The Grand Canyon in the US is a perfect example. Sedimentary rocks may also contain fossils. Fossils are the preserved remains of animals or plants that were trapped as the rocks were formed. can be a footprint, an animal shell, a piece of plant, an animal bone, or any other ancient organism. The oldest fossils ever found are 4.5 billion years old!
Questions: Write your answers. 1. What are these sedimentary rocks made up of? a. Limestone: b. Shale: c. Conglomerate: 2. What are sediments? 3. Where are most sedimentary rocks formed? III. Metamorphic rocks Metamorphic rocks are created from igneous and sedimentary rocks that have changed from very high heat and pressure to become new kinds of rocks. This happens when rocks are pushed by mountains, volcanoes, or earthquakes. The Earth's crust moves and presses the rocks very tightly together and creates high heat and pressure. Metamorphic rocks are very solid, shiny, and usually hard. Examples: Questions: Fill in the blanks. 1. Metamorphic rocks are created from and rocks. 2. Rocks are pushed by,, or to form metamorphic rocks. 3. The rocks are changed by high and. 4. Metamorphic rocks are usually very,, and.
Comparing Rocks We can classify rocks by their characteristics, color, texture, or hardness. Igneous Rocks Sedimentary Rocks Metamorphic Rocks Created by magma and lava. Do not have fossils Not layered Usually hard Usually black or grey color May have air pockets Created by compressed layers of sediment. Contain fossils Usually layered May be hard or soft Mostly brown or grey Tend to break along layers Created from other rocks by heat and pressure. May have fossils Flattened layers Very hard Many colors Shiny Review Questions: Write your answers. 1. Which type of rock is formed when molten rock cools and solidifies? 2. Which two types of rocks may contain fossils? 3. Give two examples of igneous rocks. 4. Give two examples of metamorphic rocks. 5. What two factors change rocks into metamorphic rocks? Finished! Good Job! Thank you!