Term
| What is the most common mineral group found in the crust and what is its principle elements? |
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Definition
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Term
| How do silicate tetrahedra join together to form silicate materials? |
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Definition
| Chemically, one Si^(4+) forms with four O^(2-) making SiO4^(4-) |
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Term
| What are the most common elements in the earth? Where are they found? |
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Definition
| In order of abundance: Iron (core/mantle), Oxygen, Silicon (crust), Magnesium (mantle) , Nickel (core), Sulfur (core) |
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Term
| Define Volcanic Igneous Rock |
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Definition
| (extrusive) Form when magma rises to Earth's surface |
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Term
| Define Plutonic Igneous Rock |
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Definition
| (intrusive) Form when magma solidifies below Earth's surface |
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Term
| Give an example of VOLCANIC rocks that formed from FELSIC magma |
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Definition
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Term
| Give an example of VOLCANIC rocks that form from MAFIC magma |
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Definition
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Term
| Give an example of VOLCANIC rocks that form from INTERMEDIATE magma |
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Definition
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Term
| Give an example of PLUTONIC rocks that form from FELSIC magma |
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Definition
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Term
| Give an example of PLUTONIC rocks that form from MAFIC magma |
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Definition
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Term
| Give an example of PLUTONIC rocks that form from INTERMEDIATE magma |
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Definition
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Term
| How does mafic magma differ from felsic magma? |
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Definition
| Mafic - silica poor, dark; Felsic - silica rich, light |
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Term
| Why does texture vary in igneous rocks? |
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Definition
| In volcanic igneous, the magma cools rapidly so the grains are fine (microscopic), and in plutonic igneous, the magma cools slowly so the grains are large and visible |
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Term
| What are the three ways to melt rocks? |
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Definition
| Increase Temperature, Decrease Pressure, Add a flux |
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Term
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Definition
| Occurs when some minerals in a rock melt while others remain solid; felsic melt first - mafic last; Partial melting forms a more felsic rock than parent |
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Term
| How does melting occur at a mid ocean ridge? |
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Definition
| Solid asthenosphere rises to fill divergent gap due to decrease in pressure (decompression melting) |
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Term
| How does melting occur at a hot spot? |
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Definition
| Melting occurs with an increase in temperature |
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Term
| How does melting occur at an OC subduction zone? |
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Definition
| Partial melting of mantle + water (flux) = mafic/intermediate magmas |
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Term
| Clastic Sedimentary Rocks |
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Definition
| composed of fragments of minerals and rocks (sandstone, shale) |
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Term
| Chemical Sedimentary Rocks |
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Definition
| composed of dissolved minerals that have precipitated from a solution (rock salt) |
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Term
| Biochemical Sedimentary Rocks |
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Definition
| composed of decomposed living organisms (limestone, coal) |
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Term
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Definition
| the physical or disintegration of rocks when exposed to the environment (fracturing) |
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Term
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Definition
| chemical reactions that break down materials and remove soluble materials from a rock (dissolution) |
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Term
| How does transportation control size, shape, and sorting of clastic sediment? |
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Definition
| Further from source means rounder, smaller and more quartz-rich sediments; Also Steepness of slope, strength of current and agent of transport |
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Term
| How and why do rocks behave differently at shallow and deep levels in the crust? |
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Definition
| At shallow depths, most rocks are brittle and break under stress where at deeper depths, rocks flow due to ductile deformation (all due to P and T) |
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Term
| What conditions are necessary for metamorphism? |
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Definition
| Increasing temperature and/or pressure and/or the presence of fluids |
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Term
| Name four metamorphic rocks and give their relationship with their parent rock. |
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Definition
| Slate>Schist>Gneiss; Limestone>marble |
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Term
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Definition
| Occurs due to increasing P and T along plate boundaries and subduction zones |
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Term
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Definition
| Occurs due to increasing T near magma (where magma swells above subduction zone) |
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Term
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Definition
Weathering>Erosion/Transport> Deposition>Burial>Lithification>Metamorphism>
Uplift(or Melting>Solidification>Uplift)> Weathering |
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Term
| What are some natural hazards associated with earthquakes and volcanoes? |
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Definition
| Volcanoes - lava flows, pyroclastic flows, lahars, volcanic ash; Earthquakes - building collapse, aftershocks, tsunamis, flooding, fire |
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Term
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Definition
| Horizontal Line on an inclined surface |
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Term
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Definition
| inclination or slope of surface (measured from horizontal) |
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Term
| What are the three major types of faults? |
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Definition
| Normal Fault, Reverse Fault, and Strike-Slip Faults |
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Term
| How do rocks deform before and after fault movements that produce earthquakes? |
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Definition
| Before faulting, rocks strain under force. After enough force has been applied, slipping occurs and then the strained rocks return to original shape |
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Term
| How do earthquakes accumulate displacements that account for 100s of km of movement between tectonic plates? |
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Definition
| They generate vibrations that travel through seismic waves |
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Term
| How do scientists use seismic waves to locate earthquakes? |
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Definition
| Seismic Stations sense the seismic waves and measure the time distance between the P and S waves, they then use other stations to triangulate where the epicenter is depending on the time between P and S. |
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Term
| How do scientists use seismic waves to measure earthquakes? |
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Definition
| For shallow earthquakes, the amplitude of the S-wave is used to determine the strength, then the amplitude and distance is graphed on a nomograph and the intersection of the central line is the magnitude |
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Term
| What is the difference between magnitude and intensity? |
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Definition
| Magnitude (objective) measures the energy released by an earthquake where intensity (subjective) is determined by the amount of shaking at a location by a person |
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Term
| Five hazards associated with earthquakes |
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Definition
| Landslide, Rupture, Structural Damage, Bridge Failure, liquefaction of fill |
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Term
| What are some geological conditions likely to result in greater risk from future earthquakes? |
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Definition
| Middle East - collision of Arabian plate is causing thrust faults and strike-slip faults; Anywhere on a coast near a trench; Continental rift in east africa |
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Term
| What volcanic hazards were associated with the eruption of Mount St. Helens? |
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Definition
| Pyroclastic Flow > Column of Volcanic Ash(East) > Lahars |
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Term
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Definition
| a measure of a material's resistance to flow |
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Term
| What is an everyday material with high viscosity? Low? |
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Definition
| High - syrup; low - water |
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Term
| What controls magma viscosity? |
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Definition
| Magma's viscosity is controlled by its temperature, composition, and crystal content (less temp,more crystals, and more silicate chains = more viscous) |
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Term
| How does viscosity influence volcanic eruptions? |
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Definition
| More viscosity causes pressure and gas to build up leading to a sudden, violent eruption |
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Term
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Definition
| Broad, gently curved slopes; varies in size; contain a crater with fissures on the summit; basaltic lava flows with small amounts of scoria/volcanic ash |
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Term
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Definition
| Steep slopes with crater at top; usually smaller than shield; explosive (due to viscous lava) |
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Term
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Definition
| Generation of felsic magma chambers > magma reaches surface and roof sinks into magma chamber > eruption causes eruption columns and pyroclastic flows, at this time the rest of the roof sinks to below the original surface depth |
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Term
| What are characteristics of a flood basalt? |
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Definition
| an eruption with a large volume of mafic magma on land through fissures, not associated with any particular plate boundary |
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Term
| How do flood basalts change the climate? |
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Definition
| eruptions release large amounts of sulfur dioxide which causes acid rain and reflects sunlight; also carbon dioxide is released which affects global warming; kills many animals |
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Term
| How do geologists try to predict an eruption? |
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Definition
| Volcanoes occur after increased seismic and gas activity as well as after changes in topography/shape and temperature |
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Term
| What are some differences between volcanic and plutonic igneous rocks? |
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Definition
| Volcanic is formed at the surface, made of small grains, may solidify in the presence of water, and contains visible grains. (Plutonic is opposite) |
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Term
| What defines a normal fault? |
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Definition
| Hanging wall is sinking down |
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Term
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Definition
| The walls are sliding perpendicularly |
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Term
| What depth do earthquakes most commonly occur? |
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Definition
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Term
| What are three characteristic features of a volcano? |
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Definition
| Magma vent, crater, fissures |
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Term
| Volcanic Dome Characteristics |
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Definition
| viscous lava, relatively small, can be explosive, occurs adjacent to craters of composite volcanoes |
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Term
| Shield Volcano Characteristics |
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Definition
| liquid lava emitted from a central vent |
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Term
| Scoria/Cinder Cone Characteristics |
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Definition
| Explosive Liquid lava, small, emitted from a central vent |
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Term
| Composite/Stratovolcano Characteristics |
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Definition
| more viscous lavas, much explosive (pyroclastic) debris, large, emitted from a central vent |
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Term
| Basaltic Magma with plenty of dissolved gas is likely to form a... |
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Definition
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Term
| What kind of sediments/rock types are found at a caldera? |
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Definition
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Term
| How does the depression form during a caldera eruption? |
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Definition
| the chamber roof collapses after magma is erupted |
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Term
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Definition
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Term
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Definition
| layers of ash that fall to ground |
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Term
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Definition
| 1883 eruption in Indonesia |
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Term
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Definition
| a sheet-like mass of magma rising to a fissure |
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Term
| What natural events could cause a tsunami? |
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Definition
| underwater landslides, submarine earthquakes, volcanic eruptions |
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Term
| How often does Yellowstone erupt? When was the last one? |
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Definition
| 600,000-700,000 years; 640,000 years ago |
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Term
| What is used to determine earthquake magnitude? |
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Definition
| the amplitude of a seismic wave |
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