The Rock Cycle Ag Earth Science – Chapter 3.1 3.1 Vocabulary mineral  A natural occurring, inorganic crystalline material with a unique chemical composition rock  A consolidated mixture of minerals igneous rock  A rock formed by the crystallization of molten magma sedimentary rock  Rock formed by from weathered products of preexisting rocks that have been transported, deposited, compacted, and cemented metamorphic rock Rock formed by the alteration of preexisting rock deep within the Earth by heat, pressure, and/or chemically active fluids rock cycle A model that illustrates the origin of the three basic rock types and the interrelatedness of Earth materials and processes magma A body of molten rock found at depth including any dissolved gases and crystals lava Magma that reaches the Earth’s surface Features of Some Sedimentary Rocks  The many unique features of sedimentary rocks are clues to how, when, and where the rocks formed  Each layer is a “time period”  Fossils are unique in sedimentary rocks Ag Earth Science – Chapter 3.4 3.4 Vocabulary metamorphism  The changes in mineral composition and texture of a rock subjected to high temperatures and pressure within the Earth contact metamorphism  Changes in rock caused by the heat from a nearby magma body regional metamorphism  Metamorphism associated with large-scale mountain building hydrothermal solution  The hot, watery solution that escapes from the mass of magma during later stages of crystallization Formation of Metamorphic Rocks  Metamorphism – “to change form”  Formation of Metamorphic Rocks  Most metamorphic changes occur at elevated temperatures and pressures  These conditions are found a few kilometers below the earth’s surface and extend into the upper mantle Formation of Metamorphic Rocks  Types of Metamorphism  Contact Metamorphism – Hot magma moves into rock  Regional Metamorphism – large scale deformation and high-grade metamorphism due to extreme pressures and temperatures (Example – mountain building) Agents of Metamorphism  Agents of Metamorphism  The agents of metamorphism are heat, pressure, and hydrothermal solutions Agents of Metamorphism  Heat – Most important agent of metamorphism Provides energy for chemical reactions Heat comes from magma and change in temperature with depth Agents of Metamorphism  Pressure (Stress) – Increases with depth (example – bottom of swimming pool) Pressure causes spaces between minerals to close = greater density Agents of Metamorphism  Reactions to Solutions – solutions that surround mineral grains aid in recrystallization by making it easier for ions to move When hot, water-based solutions escape from magma, they are called hydrothermal solutions These hot fluids promote recrystallization Classification of Metamorphic Rocks  The texture of metamorphic rocks can be foliated or nonfoliated Classification of Metamorphic Rocks  Foliated Metamorphic Rocks – a texture that gives the rock a layered appearance Classification of Metamorphic Rocks  Nonfoliated Metamorphic Rocks – a texture that does not exhibit a banded or layered appearance [...]... subjected to extreme pressure and heat, they change in metamorphic rock The Rock Cycle Powers of the Earth s Rock Cycle  Heat from the Earth s interior are responsible for forming both igneous and metamorphic rocks  Weathering and the movement of weathered materials are generated by the sun’s energy and produce sedimentary rock Ag Earth Science – Chapter 3. 2 3. 2 Vocabulary ignis  Latin word for “fire”... Interactions among the Earth s water, air, and land can cause rocks to change from one type to another  The continuous processes that cause rocks to change make up the rock cycle  When magma (molten material beneath the Earth s surface) cools and hardens, igneous rocks form Magma that reaches the surface is called lava The Rock Cycle  When weathered (process by which rocks are physically and chemically broken... calcium-rich plagioclase feldspar andesitic composition  A composition of igneous rocks lying between felsic and mafic ultramafic  Igneous rock composed mainly of iron and magnesium-rich minerals Formation of Igneous Rocks  Igneous – Comes from the Latin word “ignis” which means “fire” Formation of Igneous Rocks  Intrusive Igneous Rocks – rocks that form when magma hardens (cools) beneath the Earth s... 3. 2 3. 2 Vocabulary ignis  Latin word for “fire” intrusive igneous rock  Igneous rock that formed below the Earth s surface extrusive igneous rock  Igneous rock that has formed on the Earth s surface porphyritic texture  An igneous texture consisting of large crystals embedded in a matrix of much smaller crystals granitic composition  A compositional group of igneous rocks that indicate a rock is... of rock at or near the Earth s surface sediments Loose particles created by weathering and erosion of rock, by chemical precipitation from solution in water, or from the secretions of organisms and transported by water, wind, or glaciers Rocks  A rock is any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet  Rocks are classified into 3 major types  Igneous... beneath the Earth s surface  Example – Granite Formation of Igneous Rocks  Extrusive Igneous Rocks – rocks that form when lava hardens (cools) above the Earth s surface  Example – Rhyolite Classification of Igneous Rocks  Texture and composition are two characteristics used to classify igneous rocks Classification of Igneous Rocks  Course Grained Texture – Slow cooling = large crystals Large crystals