Download
1 / 19
190 likes | 304 Vues
The Changing Earth. Chapter Thirteen: Formation of Rocks. 13.1 The Composition of Rocks 13.2 Igneous Rocks 13.3 How Rocks Change. 13.3 How rocks change. Rocks are formed when lava or magma solidifies.
E N D
Chapter Thirteen: Formation of Rocks • 13.1 The Composition of Rocks • 13.2 Igneous Rocks • 13.3 How Rocks Change
13.3 How rocks change • Rocks are formed when lava or magma solidifies. • These rocks can become other kinds of rocks when they are broken down then cemented together with other sediment, or changed by heat and pressure.
13.3 How rocks change • Sedimentary rocks are formed from pieces of broken down rock. • Sedimentary rocks are the most common rock found on Earth’s surface.
13.3 Sedimentary Rocks • Sedimentary rocks are identified by the size of the particles that form them. • mudstone • sandstone • conglomerate
13.3 Sedimentary Rocks • Most fossils are found in sedimentary rock layers. • Sedimentary rocks hold clues to the past. Where might organisms get covered by sediments?
13.3 Metamorphic Rocks • Metamorphismmeans to change the form of something. • A metamorphic rockis a rock formed from another kind of rock due to heat and pressure.
13.3 Metamorphic rocks • When magma comes in contact with another type of rock, the high heat may form metamorphic rock near the point of contact. • This is called contact metamorphism.
13.3 Metamorphic rocks • Limestone is a rock made of shells. • During contact metamorphism limestone becomes marble under heat and pressure.
13.3 Metamorphic rocks • High-grade metamorphisminvolves high pressure and either low or high temperatures. • In this process, the minerals in a rock change to form new minerals.
13.3 Metamorphic rocks • Heat and pressure result when colliding continents form mountains at a convergent boundary. • Mountains are where we find metamorphic rocks.
13.3 Metamorphic rocks tell great stories • Geologists use rocks as clues to understand the history of Earth.
13.3 The rock cycle • There are many processes that keep rocks moving through a cycle: • weathering, • erosion, • compaction and cementation, • metamorphism, or • melting and crystallizing.
Geology Connection How Do You Grow a Diamond? • Diamond is a clear, hard crystal. To grow a diamond, you need carbon atoms to collect as a sparkling crystal.
Activity Metamorphism • In this activity, you will simulate the processes of contact and regional metamorphism. • Rock can change from one form to another using heat and pressure.
