Did you know the Earth is a giant rock? • Minerals are nonliving, solid substances • They occur naturally - they are not made by people • Minerals have different shapes, colors, weights, and degrees of hardness • Minerals come together to form rocks •There are three types of rocks: •Each type of rock is formed in a different way • Igneous rocks form when molten material cools and hardens. – If the molten material is inside the earth, it is called magma. – If the molten material is on the earth’s surface, it is called lava. • The molten material crystallizes into different minerals. • The properties and sizes of the various crystals depend on the magma’s composition and rate of cooling. • Magma pushes up toward the surface. • A volcano forms on the surface. • Lava flows out of the volcano and cools quickly, forming igneous rocks. • Underground magma pools form, the magma cools slowly, forming crystallized igneous rocks. Examples of Igneous Rocks… Obsidian Pumice Granite Basalt The beauty of Pumice • Sedimentary rocks are made of sediments – Sediments come from eroded igneous, metamorphic, and other sedimentary rocks, and the remains of dead plants and animals. • These sediments are deposited in layers and are then squeezed and compressed into rock. • Most fossils are found in sedimentary rocks. • Over time, eroded sediments deposited at the base of a river. • Under great pressure, the sediments are pressed or squeezed to form sedimentary rocks. Examples of Sedimentary Rocks… Shale Limestone Sandstone Conglomerate Sandstone Sedimentary Samples • Metamorphic rocks form when sedimentary, igneous, or other metamorphic rocks are transformed by great heat and/or pressure. • The word “metamorphic” come from the Greek language and means “to change form”. • Sediments sink and add pressure on lower rocks. • Heat and pressure beneath the surface change the mineral make-up older rocks, forming new metamorphic rocks. Examples of Metamorphic Rocks… Marble Gneiss Schist Metamorphic Mts. Metamorphic Rock: Before and After Types of Rocks Igneous Sedimentary Metamorphic Made from Magma That has Cooled and Hardened Made from Sediments Under Under Pressure Form when Heat or Pressure Changes the Minerals into New Minerals Rock cycle graphic: Earth Science: Part 2, (2002). The rock cycle. http://www.beyondbooks.com/ear82/7.asp Rock formation animations: Rocky the Rock Hound. http://www.fi.edu/fellows/fellow1/oct98/ Gravel background: sprott.physics.wisc.edu/ fractals.htm Sedimentary, igneous, and metamorphic fill photos: http://wrgis.wr.usgs.gov/docs/usgsnps/rxmin/rock.html Title of Lesson: Rocks Rock! Content Area: Science Grade Level: Third Grade Subject: Rocks and Minerals Objectives: •The student will be able to tell that all rocks are made of minerals. •The student will be able to name the three types of rocks. •The student will be able to describe the three ways that rocks are formed. •The student will be able to explain the rock cycle. Purpose of Presentation • To activate and build the students’ schema and background knowledge on rocks. • To explain the three types of rocks in more detail than the textbook. • To increase student interest in the topic of rocks. • To accommodate visual and auditory learners.