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73 Cards in this Set
- Front
- Back
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What rock makes up the mantle?
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Peridotite
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What is the boudary between the crust and the mantle?
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Moho
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How do we know about the upper mantle?
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By studying xenoliths
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What layer does the deepest well drilled in Russia drill into?
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Continental Crust
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What do seismic waves locate?
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Boundaries between rock layers and rock layer depths
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Define mineral
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solid, naturally occuring, inorganic, definite chemical composition, and definite arrangement of atoms
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Solid Solution
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ions of similar size and charge can substitute for each other
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Polymorph
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2 minterals with the same composition, but different crystal structure
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How are minerals classified?
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By chemical composition and crystalline structure
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Bonds
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Electrical forces of attraction
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Where does bonding take place?
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Outer Shells
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Ionic bond
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Attraction of oppositely charged ions
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Example of Ionic Bond
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NaCl - Halite
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Covalent Bond
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3,4,or5 electrons tend to share electrons
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Example of covalent bond
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Diamond
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Metallic Bond
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Electrons move freely among atoms
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Example of Metallic Bond
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Copper
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Van der Walls Bond
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Weak and holds layers of atoms togeter in sheets
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Example of Van der Walls Bond
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Mica, Talc
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What does bonding determine?
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Cleavage and fracture
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What is the most common Si mineral?
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Feldspar
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Isolated Tetrahedron
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single units bonded to positively charged ions (metals)
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Single chains
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share 2 corner O ions
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Double Chain
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share 2 cornor O ions in linear chains that are linked by sharing O-
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Sheet Silicates
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3 oxygen at the base are shared with other tetrahedron
Ex. - Micas |
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Framework
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4 oxygen shared by adjacent tetrahedron forming a 3D structure.
Ex. Quartz |
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Chain Silicates
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form needles, columns, or fibers
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Does Quartz cleave or fracture? Why?
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Fracture, oxygen bonds are equally strong in all directions
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Does feldspar cleave or fracture? Why?
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Cleave, some of the Si is replaced by Al.
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Why does quartz have many colors?
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Open structure allows to trap stray ions (impurities)
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Lithosphere
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Solid outer shell consisting of continental/oceanic and upper mantle
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Continental Drifect
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Idea that continents move freely over earth's surface
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Alfred Wegner
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Proposed continental drift
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Pangea
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supercontinent formed
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Midocean Ridges
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discovery leading to the acceptance of continental drift and plate tectonics
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What mineral records paleomagnetism?
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Magnetite
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What moves in polar wandering?
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Continents
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Seafloor Spreading
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seafloor separates at ocan ridges where upwelling magma creates new crust
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Who proposed seafloor spreading?
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Harry Hess
Said that continents and oceans move together |
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What do magnetic anomalies predict?
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age of the seafloor and rate of seafloor spreading
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Wear is the oldest/yougest seafloor located?
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oldest - near edges of continents
yougest - mid ocean ridges |
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Age of seafloor
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180 million
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Which ocean moves fastest?
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Pacific
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What two theories does plate tectonics combine?
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seafloor spreading and continental drift
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Therman convection cells
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driving mechanism for plate tectonics
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What do thermal convection cells determine?
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Where trenches and spreading ridges are located
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Divergent Plate Boundary
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plates split and move apart
ex. rift and ?new ocean |
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Transform PB
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plates slide laterally past each other
ex. fault |
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oceanic-oceanic pb
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2 oceanic plates collide and one subducts
ex. deep trenches and volcanic island arc |
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oceanic-continental pb
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oceanic plate subducts under cont. plate
ex. trench and volcanoe on land |
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cont-cont pb
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2 continents collide
ex. creates nonvolcanic mtns |
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Hot spots
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plume of hot molten rock
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what do hot spots record?
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plate movement
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What drives the rock cycle?
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plate tectonics
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Sedimentary rocks
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continent edges
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igneous rock
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midocean ridges/rifts
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metamorphic rock
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transform pb (faults)
ex. San Andreas Fautl |
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Ophiolites
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fragment of oceanic crust and upper mantle on land
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4 parts of Ophiolites
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deep sea sedimentary rocks, oceanic crust, gabbro, and upper mantle
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Ocean Crust is composed of
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Gabbro and Basalt
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Cont. Margin Parts
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cont. shelf, cont rise, cont slope
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Cont. Shelf
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between shoreline and cont. slope
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cont. slope
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cont. crust changes to oceanic crust
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cont. rise
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formed by overlapping submarine fans
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Turbidity
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currents transport and deposit muds/silts on continental slopes and submarine canyons
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Parts of passive cont. margin
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broad flat cont. shelf, cont slope, cont rise, and vast abyssal plain
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Sigsbee Abyssal Plain has
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rising salt domes
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Gulf of Mex reefs sit upon
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rising salt domes
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The Atlantic coast slide shows
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deep submarine canyons
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Parts of an active cont. margin
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narrow cont. shelf, cont. slope, ends in a trench
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What is associated with active margins?
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subduction zones and transform faults
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Features found in a rift valley
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hydrothermal vents, black smokers, sulfide chimneys, and pillow basalt
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2 deep sea sediments
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pelagic clay and calcareous/siliceous ooze
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