Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Sorting Igneous Rocks 3 Types of Rocks • Igneous = FIRE • Sedimentary • Metamorphic Goals: • Describe how igneous rocks form. • Identify the physical characteristics and compare/contrast: – Igneous Rocks vs. Sedimentary Rocks – Extrusive vs. Intrusive Igneous Rocks • Make inferences about the geological processes that formed rocks through observing their physical characteristics. Some Igneous Rocks Granite Diorite Pegmatite Gabbro Obsidian Pumice Igneous Rock = made in fire 1. 2. Magma rises Lava erupts 2 kinds of Igneous Rock 1. Intrusive = inside Earth 2. Extrusive = outside Earth Lava erupts Magma rises Intrusive Igneous rock forms • when magma rises into the cracks in the Earth’s crust and cools and hardens very slowly. 1. Intrusive Igneous rock • The magma cools and hardens very slowly because it stays warm and insulated inside the crust. 1. Granite Intrusive Igneous Rocks Granite Medium size grains • Magma cools slowly beneath the Earth’s surface. • The longer it takes the magma to cool, the larger the grains can grow out of the magma before it hardens into rock. Pegmatite Large size grains • Pegmatite is very coarse grained (big grains) so the magma cooled and hardened very slowly. The grains in rocks are made of minerals. Minerals are natural forming materials found on and in the Earth. Each mineral has a different color. Granite Different color Minerals in Granite Mineral called Quartz – slowly cooled and hardened into crystals Different Minerals Just as different foods can make up a cookie, different minerals can make up a rock. Some Intrusive Igneous Rocks Granite Peridotite Granite Peridotite Gabbro Gabbro Some Intrusive Igneous Rocks Andesite Diorite 2 kinds of Igneous Rock 1. Intrusive = inside Earth 2. Extrusive = outside Earth Lava erupts Magma rises Extrusive Igneous rock forms when: • lava erupts out of a volcano and then cools and hardens quickly into rock. Extrusive Igneous rock • It cools and hardens quickly into rock because it is exposed to air or water. Basalt Extrusive Igneous Rocks Basalt Rhyolite • Lava cools quickly at the Earth’s surface • Lava that cools very quickly produces very fine grains or really small grains. • Can you see any grains? • You can’t really see mineral grains in Extrusive Igneous rocks because they cool and harden too fast and the minerals don’t have time to form into crystals or big grains. Some Extrusive Igneous Rocks Basalt Rhyolite Obsidian Obsidian Pumice Scoria How the Earth was Made • Yosemite: Minute 13. How cooling effects rock strength/crystal size. Activity 2: Sorting Igneous and Extrusive Rocks Lab 1 • Your group will examine a case of rock samples from the Grand Canyon region and rock samples from the Cascade Mountain region. • Sort the rocks into sedimentary or igneous rocks based on their physical characteristics. Complete your group lab response. Lab 2 • After reviewing slides presenting extrusive and intrusive igneous rock, sort your rocks into these groups based on their physical characteristics. Lab 3 • Your group will receive samples of igneous rock. Infer which geological processes may have formed this rock. Your group will tell the “story of the rock” when you present it to the classroom.