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38 Cards in this Set
- Front
- Back
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Compare & Contrast Viscosity |
Low Viscosity: water, flows easily, less viscous, hotter magma, mafic lava High Viscosity: honey, flows slowly, highly viscous cooler magma, felsic lava |
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What determines minerals characteristics? |
Physical properties such as: Color, streak, luster, hardness, fracture and cleavage |
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Silicate minerals are the most abundant in crust and mantle |
95% of continental crust and majority of minerals in oceanic crust and mantle |
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Know the types of cleavage and an example of each |
Basal-one direction Prismatic-two directions at right/non-right angles Cubic-three directions at right angles Rhombohedral-three directions at non-right angles Octahedral-four directions |
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What information can minerals tell us? |
give information about pressure, temperature, and water chemistry |
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What is the definition of a mineral? |
-naturally occurring -inorganic solid -definable chemical composition -orderly arrangement of atoms |
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what is the difference between cleavage and fracture? |
Cleavage: breaks along definite planes of weakness Fracture: breaks along irregular boundaries |
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what is the difference between luster and color? |
Luster: how a mineral scatters light Color: how a mineral interacts with light |
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why can minerals have the same composition, but be different colors? |
because of small differences in composition |
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What is the hardness of your fingernail and a glass plate? |
Fingernail H=2.5 Glass H=5.5 |
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What is the difference between sialic and ferromagnesium? |
Sialic: Light colored with silicon and aluminum Ferromagnesian: darker with more iron (Fe) and magnesium |
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Silicate minerals are classified according to their |
crystal structure |
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bond type determines the physical properties of minerals |
Chemical bonds |
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What are the three bond types? give an example for each |
Ionic-electrons transferred Covalent-electrons shared Metallic-electrons roam between atoms |
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Igneous rocks are classified according to |
Composition-what minerals the rock contains Texture-size & shape; look and feel |
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what is the difference between phaneritic and aphanitic? |
Phaneritic-crystals visible with naked eye Aphanitic-microscopic crystals not visible to the naked eye |
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difference between intrusive and extrusive? |
Intrusive-crystallizes inside the crust from magma Extrusive-crystallizes outside the crust from lava |
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difference between magma and lava? |
Magma-underground Lava-above ground |
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what is fractional crystallization? |
magma changes composition continually |
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fractional crystallization process |
-magma cools, mafic minerals form first -denser, sink to bottom of magma chamber -removes iron and magnesium from melt -magma chamber becomes felsic or silica rich |
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the fractional crystallization process is called |
Bowen's Reaction Series |
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Explain how magma becomes felsic overtime |
fractional crystallization or Bowen's reaction series; melting; high temperature over long a period of time |
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why is quartz the last mineral to form on Bowen's Reaction Series? |
quartz is the last mineral to crystallize from a cooling of felsic magma |
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Which minerals form first as magma cools? |
mafic minerals (olivine, pyroxene, amphibole, biotite mica, plagioclase feldspar) |
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be able to identify and differentiate between the three types of lavas |
Basaltic-low viscosity mafic lavas, typically erupt at 1000-1200 degrees C Rhyolitic-high viscosity felsic lavas, typically erupt at 800-1200 degrees C; most explosive Andesitic-intermediate in composition and viscosity between mafic and felsic magmas |
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What are some types of basalt flows? |
Flood- thick, widespread accumulations of basalt, typically fed by fissures Pahoehoe-low viscosity basaltic lava with ropy texture Aa-low viscosity basaltic lava characterized with jagged, blocky texture Pillow-forms beneath the water, characterized by glassy pillow filled with crystalline basalt Vesicular-trapped gases form bubbles(vesicles) |
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How are pyroclasts classified? |
size (pyroclasts definition: volcanic rocks with are violently ejected into the atmosphere during an eruption) |
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what is the difference between a lahar and pyroclastic flow? |
water (lahar-water, gas & pyroclastic debris pyroclastic flow-gas & pyroclastic debris) |
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Explain how pyroclastic material is lithified to become a rock |
sediments compact under pressure (my best guess) |
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what are the three classifications of volcanoes? explain each type |
Shield-formed from basaltic lavas, gentle sides, wide, non-violent eruptions Cinder-cones- formed from basaltic pyroclastic material, steep sides, small, short-lived single event Stratovolcanoes-alternating pyroclastic deposits and andesitic lava flows, intermediate slopes, large, intermittent eruptions, highly explosive |
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what is the difference between a crater and caldera? |
-calderas are larger -caldera material comes from magma chamber; crater material comes out of vent -calders:magma chamber roof collapses; craters-rim collapses into vent |
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what is the leading cause of volcanic-related deaths? |
Pyroclastic flows |
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what are some of the ways of predicting volcanic eruptions |
-earthquake activity -changes in heat flow -changes in shape -increase in gas and steam emissions |
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Decompressing melting |
Decrease in pressure |
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Volcanic ash |
Fine grain dust, sticks in air (volcanic tuff) |
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Lahar |
Volcanic mudslides |
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Fissure |
Cracks in earth's surface |
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Adding water |
Causes rock to melt at lower temperatures |
