GLY 1000 Fall 2012 Final Exam Review Sheet Chapter 2 Understand different aspects of plate tectonics Very Important including different types of plate boundaries theory of continental drift Plate tectonics is a model hypothesis that explains the geologic structure processes of the earth Divergent boundary slide away from each other Convergent boundary slide toward each other mid ocean ridge Transform boundary slide past each other where plates are neither formed nor destroyed Continental drift size and position of plates change over time 200 million years ago all together Pangaea Know general layering of the earth ex Core mantle etc Lithosphere earth s surface the crust Asthenosphere a plastic layer upper mantle The lithosphere is broken up into several plates and the plates float on the asthenosphere Know generally where continents on earth were located millions of years ago in relation to where Know where earthquakes and volcanoes are likely to occur on earth edges of plates Know three main types of faults Normal extensional tension forces Reverse compressional forces Strike slip shear forces Know difference between flux and decompression melting Flux melting occur at subduction zones plates bring down water bearing sediments Lowers melting point of surrounding mantle induces melting Decompression Melting occurs at mid ocean ridges and hot spots The process of the mantle decompressing as it rises to the surface Know what a hotspot is and where they are located on earth 2 theories 1 long lived narrow plumes of hot mantle rock that rise rapidy from deep in the Earth and undergo decompression melting 2 Slow decompression melting of large mass of hot mantle rock that has been sitting in the upper mantle for a long time Hawaii Yellowstone Chapter 3 Know what luster is How light is reflected from the surface of a mineral 2 types Metallic Non Metallic Know why color is not usually the best way to identify a mineral Because some minerals change color or have various forms of different color Know what streak is and why it is helpful Color of a powdered mineral which is tested by rubbing the mineral across a porcelain streak plate Understand the Mohs hardness scale and how you can use it to identify minerals When identify mineral a mineral you should mainly be able to distinguish minerals that are relatively hard 6 0 or higher on Mohs scale from minerals that are relatively soft less than or equal to 5 5 on Mohs scale You can identify the minerals hardness by comparing it to the table or the Mohs kit Understand fracture conchoidal vs irregular conchoidal tend to fracture like glass along ribbed smoothly curved surfaces irregular uneven splintery hacky Understand cleavage and how it differentiates from fracture cleavage tendency of a mineral to break along flat planes of weaker bonding Fracture cleavage is absent and mineral breaks irregulary Know special qualities of minerals we identified such as magnetism salty taste effervescence to acid Magnetite magnetism Halite salty taste Calcite effervescence to acid Given one mineral and identification sheet be able to identify it LOOK POWERPOINT Chapter 4 Understand the entire process of the rock cycle and how each type of rock becomes another type of rock understand interlocking processes such as erosion and magma formation Know basic sediment size identification Ex difference between size of cobble and sand Grain size tells us how far the grains traveled before deposition Gravel Sand Silt Clay The smaller the grain size the farther the grain traveled Know the difference between clastic and non clastic rocks Clastic made of grains called clasts fragments of rocks mineral crystals shells and plants Know difference between foliated and non foliated rocks Foliation layering and parallel alignment of mineral crystals Foliation forms perpendicular to pressure 4 types of foliation textures slaty cleavage phyllite texture schistosity gneissic banding Non foliated rocks that have no obvious layering 4 main texture types crystalline marble Microcrystalline sandy quartzite glassy anthracite Chapter 5 Know difference between magma and lava Magma below Earth s surface cools slowly forms Intrusive igneous rocks Lava above Earth s surface cools fast forms Extrusive igneous rocks Know certain magma lava forming geologic structures Ex Dikes Sills etc Magma intrusive igneous rocks Batholiths large intrusion of magma Sill horizontal intrusion of magma Dike vertical intrusion of magma Volcanic Neck core of volcano magma Lava Extrusive igneous rocks Lava flows Volcano cones made of lava or from pyroclastics Pyroclastic flows made of pyroclastics ash lapilli and volcano bombs Know three different types of pyroclastics Hint Based on size Know the difference between intrusive and extrusive volcanic rock Intrusive Plutonic molten rock cools before it reaches earth s surface Slow cooling big crystals Extrusive Volcanic Molten rock cools at the earth s surface Fast cooling tiny crystals Know different textures of igneous rocks and why they have those textures Know the difference between felsic and mafic rocks Important Felsic or granitic or sialic rocks dominated by silicon and aluminum usually light in color characteristic of continental crust forms a stiff lava or magma minerals commonly present k feldspar plagioclase quartz bitotite Mafic or basaltic rocks contains magnesium and iron silicates usually dark in color characteristic of earth s oceanic crust forms a runny lava have 46 85 mafic minerals Know how to use identification sheet to identify one igneous rock Look powerpoint Chapter 6 Generally how does a sedimentary rock form 1 Weathering the process of breaking down rocks and minerals into smaller pieces by water wind and ice This creates the grains 2 Transport Deposition grains are transported by wind or water variable distances 3 Lithification the hardening of sediment through compaction and cementation this forms the rock What is the framework and the matrix of a sedimentary rock A sedimentary rock is made up of GRAINS Grains rock fragments minerals fossils A sedimentary rock is like a cookie the chocolate chips are large grains that provide the main structure to the rock we call these grains the framework The smaller or fine grains are the stuff in between the chips the sugar butter etc we call these the fine grains the matrix What does grain shape and how well sorted the grains are tell you about the history of the rock Grain shape also tells us how far