Earth Science: Earth's Spheres; Rocks and the Rock Cycle
How do plate tectonic processes help to explain the rock cycle?
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How do scientists classify rocks?
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What are the main processes involved in the rock cycle?
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What are the major parts of the earth system?
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Where do igneous rocks come from?
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Why do igneous rocks look so different from each other?
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Forming sedimentary rocks (4)
1. Stratification 2. Deposition 3. Cementation 4. Compaction
Tuff
Accumulated ash in layers (eventually becomes sedimentary)
Hydrosphere
All forms of water
Gneissosity Foliated rock
Alternating bands of light and dark
Breccia
Angular stones and particles
Oceanic
Basalt, extrusive, mafic
Island Forming
Basaltic Ex. Hawaii
Types of Plutons
Battholith, laccoliths, dike, sill, volcanic neck
Intermediate composition
Both falsic and mafic
Chemical weathering
Breaking down or weakening of rock by chemicals
Addition or Loss of fluids
Causes restructing of atoms to produce new minerals
Increased temperature
Changes in chemical composition due to the movement of atoms Result: new minerals form Rock does not melt
Types of sedimentary rocks
Clastic Chemical Organic
Schistosity Foliated rock
Coarse grained texture in bands
Increased pressure
Compacts rock causing new crystallization May just be a texture change Resulting rock is denser and harder
What are the two ways to classify igneous rocks?
Composition Texture
Types of metamorphism
Contact metamorphism Regional metamorphism
Organic sedimentary rocks
Contain fragments of once living things Ex. Coal
4 Major sections of the earth
Crust, mantle, inner core, outer core
Deposition
Depositing of weathered materials by wind, water, or ice
Nonfoliated rock
Don't form under pressure or equal pressure on each side
What are the two igneous rock types?
Extrusive Intrusive
Extrusive rocks
Fine grained
Slaty Foliated rock
Fine grained, breaks along parallel cleavage lines
Texture and formation
Fine grained: cooled rapidly Medium grained: rapid cooling Large (coarse) grained: slow cooling allowing for larger crystals Glassy: rapid cooling Vesicular: air pockets
Muscovite or mica
Flakes off in sheets Used in joint compounding, suspending pigments in paint, plastics, rubber, asphalt roofing, cosmetics
Types of metamorphic
Foliated and nonfoliated
How do igneous rocks form?
Form when molten material cools and hardens
Clastic
Grain size and shape Conglomerate, sandstone, breccia
Continental
Granite, intrusive, felsic
Evaporate chemical sedimentary rocks
Halites (large salt source) Crystallizes water vapors
Contact metamorphism
Heat and pressure as igneous intrusion invades country rock (any of 3 types of rock)
Felsic
High silica content Granite (from continental crust)
Anthracite grade of coal
Highest grade of coal Layered and glossy
What are the three types of rocks?
Igneous Sedimentary Metamorphic
Sill
Igneous intrusion that cuts horizontally between rock (like a window sill)
Dike
Igneous intrusion that cuts vertically between rock layers (like a big wall)
Laccolith
Igneous rock Squeezed between two sedimentary layers Example: devils tower in wyoming
How Metamorphic rocks form?
Increase in pressure, temperature, and/or addition or loss of fluids
Batholith
Large Plutons that "float" through original rock and can be exposed at the surface Example: half dome in Yosemite
Igneous Plateau or Province
Large area of basalt Ex. Pacific Northwest
Regional metamorphism
Large areas where rock has experienced high pressure and temperature at tectonic plate boundaries Most Foliated (due to pressure from 2 sides)
What are Plutons?
Large deposits of intrusive igneous rocks (these masses maintain their shape)
Catastrophism
Large, cataclysmic events produce large geologic deposits and stratification Ex. The flood
What is sedimentary rock?
Layers off broken down rock, which can be igneous or metamorphic in nature
Conglomerate
Like concrete More rounded stones and particles
Cementation
Like mortar between bricks Chemical minerals that bind rocks together
Carbonate chemical sedimentary rocks
Limestone and travertine Stalagmites, stalactites
Mafic
Low silica content Basalt (ocean crust)
Lignite coal
Lowest grade of coal
Intrusive rocks
Magma cools slowly within Earths surface (larger materials).
Bituminous grade of coal
Medium grade of coal Glossy
Composition
Minerals within the rock Based on silica content
Lava
Molten rock
Magma
Molten rock within earth
Foliated rock
Parallel bands of crystals Slaty, Schistosity, Gneissosity
Boundary between two layers in atmosphere
Pause added to root layer
Coal
Plant materials Grade of coal depends on density and texture (lignite, bituminous, anthracite)
Chemical sedimentary rock
Precipitate from water sources Carbonate, evaporate, and chert
Weathering
Process of breaking down rock into smaller pieces
Stratification
Process of laying down layers
Geosphere
Rocky portions do earth in both solid and liquid forms
Sandstone
Sandy composition and texture
Texture
Size, shape, and orientation of mineral growth
Uniformation
Slow natural process overtime
Cryosphere
Solid form of water
Volcanic neck
Solidified magma in a volcanic vent Weathers less rapidly than surrounding
Compaction
Squeezing of sediments together through pressure
What is a layer of sedimentary rock called?
Strata Plural: stratum
4 major sections of the atmosphere
Troposphere (we live) Stratosphere Mesosphere Thermosphere (warmest)
Types of extrusive igneous rocks
Tuff, Island Forming, Igneous Plateau or Province
Chert chemical sedimentary rocks
Very hard and glossy
Mechanical weathering
Wind, water, or ice breaking down rock
