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Igneous, Sedimentary & Metamorphic Rocks...and the Rock Cycle PowerPoint Notes created by S. Koziol Date : 9/7/2013 Revised : ?/?/?? Slide 2 Igneous Rocks Compare and contrast intrusive and extrusive igneous rocks. Describe the composition of magma Discuss the factors that affect how rocks melt and crystallize. Classify different types and textures of igneous rocks. Recognize the effects of cooling rates on grain sizes of igneous rocks. Describe some uses of igneous rocks. Slide 3 Igneous - crystallization Igneous rocks are formed when magma crystallizes. Slide 4 Lava Lava is magma that flows out onto Earth's surface. Slide 5 Melting Point Factors that affect a rocks melting point include pressure and water content. Slide 6 Melting Point - continued As the water content of rock increases, the melting point decreases. Slide 7 Intrusive Igneous rocks that cool slowly beneath Earths crust are intrusive. Slide 8 Grain-size Extrusive rocks, which cool more rapidly than intrusive rocks, are generally more finely grained. Slide 9 Coarse-Grained Intrusive igneous rocks form coarse-grained rocks. Diorite is a coarse-grained, intrusive igneous rock that is intermediate in composition between granite and gabbro. Slide 10 Extrusive Igneous rocks that cool quickly on Earths surface are extrusive. Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. Aka volcanic glassigneous rock Slide 11 Igneous Classification Both terms describe an igneous rock which is classified based on how it is formed. Extrusive igneous rocksIntrusive igneous rocks Coarse-grained igneous rocks that cool slowly beneath Earths surface are intrusive igneous rocks. Fine-grained rocks that cool quickly on Earths surface are extrusive igneous rocks. Slide 12 Composition Classification Igneous rocks are classified as felsic, mafic, and intermediate. Slide 13 Main 3 Intermediate rocks lie between felsic and mafic rocks in silica and iron content. Felsic rocks are light-colored, have high silica content, and contain quartz and feldspars. Mafic rocks are dark-colored, have low silica content, and are rich in iron and magnesium. Slide 14 Porphyritic texture A rock that has grains of two different sizes has porphyritic texture. Slide 15 Felsic Felsic rock is light-colored rock such as granite that has high silica content. Half Dome at Yosemite National Park is composed of granodiorite Slide 16 Mafic Mafic rock is dark-colored rock such as gabbro that is rich in iron and magnesium. Slide 17 Ultramafic Ultramafic rock is rock that is very high in iron and magnesium. Ultramafic pillow-lavaspillow-lavas (YOUTUBE Link) Slide 18 Bowens A model that illustrates the predictable patterns of mineral formation from cooling magma is Bowen's reaction series. Slide 19 Ores & Gems Valuable ore deposits and gem crystals are often associated with igneous intrusions. Slide 20 Kimberlites Kimberlite is course-grained rocks associated with diamonds in igneous outcrops, named after the area of S. Africa where they were first discovered. Slide 21 Sedimentary Rocks Sequence the Formation of Sedimentary Rocks. Explain the formation and classification of clastic sediments. Describe features of Sedimentary Rocks. Describe the types of clastic Sedimentary Rocks. Explain how chemical sedimentary rocks form. Describe organic Sedimentary Rocks. Recognize the importance of Sedimentary Rocks. Slide 22 Sediments Much of Earths surface is covered not by solid rock, but by sediments. Actual outcrops are a rare feature. Slide 23 Sediments (continued) Sediments are pieces of solid Material deposited on Earths surface. Slide 24 Deposition Deposition is the process of sediments being laid down on the ground or sinking to the bottom of water. Slide 25 Lithification Lithification is the physical and chemical processes that compact and transform sediments into sedimentary rocks. Slide 26 Permineralization During lithification, parts of an organism are replaced by minerals and turned into rock. Slide 27 Erosion Landslides, moving water, wind, and glaciers cause erosion of surface materials. Slide 28 Sorted Deposits Sorted deposits are characteristic of sediments transported by water and wind. Slide 29 Weathering Effects Weathering of rock produces worn surfaces and rounded corners that are characteristic of some clastic sediment particles. Slide 30 Clastic Sediments Clastic sediment particles have worn surfaces and rounded corners. Slide 31 Breccia Breccia sedimentary rock is coarse-grained with angular fragments. Slide 32 Bedding The primary feature of sedimentary rocks is horizontal layering called bedding. (repetitive laying) Slide 33 Graded Bedding Graded bedding has the heaviest and coarsest material is on the bottom. Slide 34 Graded Bedding (continued) Graded bedding is produce in marine landslides. Slide 35 Unsorted Bedding Landslide and glaciers produce unsorted deposition. Slide 36 Cross bedding Cross bedding is inclined sediment layers that migrate forward across a horizontal surface. Slide 37 Ripple Marks One-way wave actions of wind or water produce asymmetrical ripple marks. Slide 38 Dry Land Evidence The presence of dry land in past environments allow for the deposition of four-footed animal fossils. Slide 39 Porosity Porosity is the percentage of open spaces between grains in a rock. Slide 40 Sandstone vs Shale Porosity Sandstone is porous. When its pore spaces are connected to one another, fluids can move through the sandstone, making sandstone layers valuable as underground reservoirs. However, shale has low porosity, meaning that the pore spaces are small. This hinders the movement of fluids. Slide 41 Evaporite Evaporite are layers of chemical sedimentary rocks that form from precipitated minerals. Slide 42 Compare & Contrast Conglomerates form from deposits of loose sediments on Earths surface. Both are sedimentary rocks which are classified by method of formation. Evaporites form when water evaporates from mineral- rich solutions, causing the minerals to precipitate out of the solutions. Slide 43 Limestone Limestone is an organic sedimentary rock, and is the most abundant organic sedimentary rock on Earth. It is calcite-rich (CaCO 3 ). Slide 44 Weathering If weathering did not occur, sedimentary rock would not form. Its absence would likely affect the formation of igneous and metamorphic rock as well. Slide 45 Ancient Conditions Some sedimentary rocks contain sedimentary structures that indicate the location and direction of flow of ancient rivers, the wave or wind direction over lakes and deserts, and ancient shoreline positions. Slide 46 Section 3 Metamorphic Rocks & the Rock Cycle Compare and contrast the different types and causes of metamorphism. Distinguish among metamorphic textures. Explain how mineral and compositional changes occur during regional metamorphism. Understand how rocks change from one type to another in the rock cycle. Slide 47 Contact Metamorphism Contact metamorphism results when rocks come in contact with molten rocks such as those in an igneous intrusion. Slide 48 Metamorphic - Foliated Foliated metamorphic rocks are composed of minerals with crystals that have their long axes perpendicular to pressure. Slide 49 Nonfoliated metamorphic Nonfoliated metamorphic rocks are composed of minerals that form blocky crystal shapes. Slide 50 The metamorphism of limestone results in the formation of marble. Slide 51 Foliated vs. Non-foliated Foliated rocks have distinct banding or layers that formed perpendicular to pressure. Both are textures of metamorphic rocks. Nonfoliated rocks are crystals with blocky shapes and do not have banding. Quartzite Garnet Schist Slide 52 Sedimentary vs. Metamorphic Metamorphic rocks form when high temperature and pressure cause the texture, mineralogy, or chemical composition of a rock to change without melting it. Both are types of rocks classified by method of formation. Sedimentary rocks form when sediments are cemented together. Slide 53 Rock cycle The Rock cycle is the continuous changing and remaking of rocks. Slide 54 Rock Cycle Rock Cycle Worksheet Rock Cycle Multimedia Assignment Slide 55 Earths Surface Earths Surface Graphing exercise