Exam 2 Flashcards
Mechanical Layers of the Earth,
Lithosphere Asthenosphere Lower Mantle Outer Core Inner Core;
Asthenosphere,
Solid/Elastic;
Lithosphere,
Solid/Rigid;
Lithosphere composed of,
crust and upper mantle;
Lower Mantle,
Solid/Rigid;
Outer Core,
Liquid;
Inner Core,
Solid;
Plates,
Groups of lithospheric rock all moving in the same direction
Can have ocean and continent;
Divergent Plate Boundary,
Move Apart Oceanic Ridges Mid-Atlantic Ridge East African Rift Valley Volcanoes Present Mountains;
Normal Faults and Strike Slip Faults,
Divergent;
Strike Slip are only in the,
Oceanic;
Normal Faults,
Continental and Oceanic;
Red Sea is in a,
Continental;
Rift Valleys and Mountains are in,
Continental;
Mid Atlantic Ridge,
North American/Eurasian Plates-Oceanic;
Convergent Plate Boundaries,
Ocean-Ocean
Ocean-Continent
Continent-Continent;
Example of Convergent Plate Boundary,
Japan Aleutian Islands;
Older Oceanic lithosphere consumed at subduction zone,
Convergent;
Denser plate sub-ducts,
Convergent;
Water dispensed into hot rocks above the mantle wedges-lowers melting temperature,
Convergent;
Magma from melting of mantle wedge supplies volcanoes,
Convergent;
Reverse Faults,
Convergent;
The steeper the slope,
The small the trench gap;
What boundary produces trenches and island arc volcanoes?,
Convergent;
Oceanic Plate Sub-ducted,
Ocean-Continent;
Examples of Ocean-Continent Boundary,
Andes Mountains (Nazca under South American Plate)
Cascade Mountains;
What convergent plate boundary forms Mountains Volcanoes and Trenches?,
Ocean-Continent;
What boundary forms a Reverse Fault?,
Ocean-Continent;
What happens when continent crust collides and thickens?,
Forms a Contient to Continent Boundary;
What convergent boundary forms only Mountains?,
Continent-Continent;
Example of Continent-Continent Boundary,
Himalayas (India and Eurasia);
Example of Transform Boundary,
San Andreas Fault;
What boundary forms parallel ridges and volcanoes?,
Transform;
What boundary has fracture zones?,
Transform;
How fast do Plates travel?,
1-15cm/year;
What plates are the fastest?,
Nazca. Pacific;
What plats are the slowest?,
Antarctic North American;
What do Igneous Rocks form from?,
Solidification of magma/lava and pyroclastic material;
Where do Igneous Rocks form?,
Divergent Convergent Mantle Plumes Hot Spots;
Factors affecting melting of minerals,
Pressure
Water
Composition;
Pressure,
More pressure is higher melting point;
Water,
More water lowers melting point;
Compositions,
Silica
Mafic
Felsic;
Silica Rich melt at,
Lower Temperatures;
Mafic Melts at,
Higher Temperatures (Silica Poor);
Felsic Melts at,
Lower Temperatures (Silica Rich);
What happens at Divergent Plate Boundaries?,
Magma is formed when a release in pressure allows rock in the asthenosphere to melt and raise to the surface;
What is Decompression melting?,
Magma is formed at when a release in pressure allows rock in the asthenosphere to melt and raise to the surface;
What happens at Convergent Plate Boundaries?,
Magma is formed when subduction water is released from subjecting minerals to lower melting temperature;
What is Fluid induced melting?,
Magma is formed when subduction water is released from subjecting minerals to lower melting temperature;
Coarse Grained,
Phaneritic;
Coarse Grained Igneous Rocks (Texture),
Can see Minerals/Crystals
Crystalized due to slow cooling magma within Earths Crust;
Fine Grained Igneous Rocks (Texture),
Can not see individual Crystals;
Vesicular Igneous Rocks (Texture),
Bubbles that used to be gas
Earths surface from gas rich lava
Holes;
Glassy Igneous Rocks (Texture),
No Crystals and look glassy
On surface form lava that cooled too quickly to form crystals;
Fragmental Igneous Rocks (Texture),
Rock bits ejected from Volcano (Visible Fragments)
On Surface;
How much Silica content is in Felsic?,
70%;
How much Silica content is in Intermediate?,
55%;
How much Silica content is in Mafic?,
45%;
How much Silica content is in Ultra-Mafic?,
40%;
Felsic Color,
Light (Pink White Tan);
Intermediate Color,
Intermediate (Gray White Black);
Mafic Color,
Dark (Black);
Ultra-Mafic Color,
Dark with Green;
Granite,
Coarse Grained/ Felsic;
Rhyolite,
Fine Grained/ Felsic;
Diorite,
Coarse Grained/ Intermediate;
Andesite,
Fine Grained/ Intermediate;
Gabbro,
Coarse Grained/ Mafic;
Basalt,
Fine Grained/ Mafic;
Peridotite,
Coarse Grained/ Ultra-Mafic;
Volcanoes,
A vent in the surface of the Earth through which magma and associated gases and ash erupt;
Pyroclastic Materials,
Bombs
Blocks
Ash
Lapili;
Bombs,
Smaller Rocks ejected
3;
Blocks,
Larger Rocks ejected
4;
Ash,
Tephra and glass particles (Fine particles of dirt. heavy. clogs everything. can travel far
Smallest-1;
Lapili,
Tephra that builds out of the Volcano like ash
2;
Volcano Hazards,
Pyroclastic Material
Lava Flows
Volcanic Gases;
Volcanic Gases,
50-80% Water Vapor Carbon Dioxide Nitrogen Sulfur Dioxide Hydrogen Sulfide;
Lake Nyos,
Volcanic Crater
lake included CO2 from Magma
Lake flipped and CO2 rose to the surface
15 mile radius for gas release;
Viscosity,
Resistance to flow;
High Viscosity,
High Resistance to Flow (slower) Ex: DQ Blizzard;
High Viscosity forms what volcano type?,
Strato/Composite Volcanoes;
Low Viscosity,
Low Resistance to Flow (faster) Ex: Water;
Low Viscosity forms what volcano type?,
Shield Volcanoes;
Grain size is determined by?,
Cooling Speed;
Low Viscosity has what temperature?,
High temperature;
High Viscosity has what temperature?,
Low Temperature;
Intermediate,
More Silica;
Low Temperature Magma is,
More viscous;
Felsic Magma is,
More Silica=More Viscous
Traps gases better;
Magma contains dissolved gases,
Water
Carbon Dioxide
Sulfur dioxide;
Pressure decreases allow gases to,
Form bubbles and speed up lava moving toward the surface;
Low Viscosity,
Mafic lava allows gas to escape
Non explosive eruptions
Basaltic Lava;
High Viscosity,
Felsic Intermediate Trap Gas Gas builds up until the pressure exceeds the strength of the rock Explosive Eruptions Pyroclastic deposits are dominant;
Magma compositions change,
along the way toward crystalization;
Assimilation,
Turning rock into lava;
Where are Basaltic (Mafic) Lava located?,
Divergent Plate Boundaries
Hot Spots;
Where is Andesitic (Intermediate) Lava located?,
Convergent Plate Boundaries;
Where is Rhyolitic (Felsic) Lava located?,
Convergent Plate Boundaries;
Lahar,
Volcanic mudflow of water and ash
Pick up debris such as rocks up to 10 meters in diameter;
Stratovolcano,
Felsic lava
High Viscosity;
Shield Volcano,
Mafic Lava
Low Viscosity;
Extinct,
No eruption in las 10’000 years;
Dormant,
At least one eruption in the last 10’000 years;
Active,
At least one eruption within the last few thousand years;
What Igneous Rock has the same composition as Granite?,
Rhyolite;
What properties does not depend on the chemical composition of an Igneous rock/magma?,
Grain Size/Texture;
Why are there Plates?,
Because the Earths interior is hot. leads to formation of the Asthenosphere which formed the Lithosphere;
Calderas,
A large depression typically caused by collapse or ejection of the summit area of a volcano;
Lava Dome,
A steep-sided lava flow commonly almost as high as it is wide and caused by the extrusion of extremely viscous lava;
Cinder Cone Volcano,
A rather small volcano built primarily of pyroclastic ejected from a single vent;
