Geology- Lecture 3
Terms
undefined, object
copy deck
- Define: Compressional
- When you have convergent forces
- Define: Tensional
- when you have divergent forces
- Define: Shear forces
- When you have transform boundaries
- Define: Anticlines
- looks like an A oldest in the middle
- Define: Synclines
- Looks like an U oldest on the outside
- Define Symmetrical folds
- dips the same
- Define: Asymmetrical fold
- dips are different
- Define: Overturned folds
- the top of the layer is facing the bottm
- Define: recumbent folds
- extreme overturn, when the fold is on its side
- Define: Joints
- fractures with no displacement. Lots of pressure, then pressure is releases. The rock fractures apart
- Define: Faults
- Fractures with displacement
- Define: Dip-Slip fault
- the direction of movement is along the fault
- Define: Normal faults
- when the hanging wall moves down relative to the footwall. Rocks pulled apart and lengthened.
- Define: Reverse Fault
- When the hanging wall moves up relative to the footwall. It shortens the rock unit
- Define: Thrust fault
- a reverse fault that has a gentle dip
- Define: Strike-Slip Fault
- when the rocks move side to side (left or right lateral)
- Define: Body Waves
- P wave (fast, move through solids and liquids, fastest) S wave (can't go through liquids)
- Define: Seismometers
- measures earthquakes: P wave --> S wave --> Surface wave
- How do you figure out how far away an earthquake is?
- the time between P and S waves
- How do figure out where the earthquake is?
- using three seismographs
- How do you measure the size of an earthquake?
- maximum S wave
- Define: Richter Scale
- -based on amplitude of largest seismic wave -based on Log10 scale
- Define: Modified Mercalli Intensity Scale
- based on touchy feely science. "Are animals acting funny"
- What are some famous earthquakes in North America
- -San Fransciso 1960. Most of the city destroyed. Got america looking at earthquakes -Alaska 1964, largest earthquake in USA
- What are some famous earthquakes in the world
- -Chile 1960, largest in the world -Turkey 1999, killed 17000 due to shitty buildings -Sumatra 2004, Tsunami
- What are earthquake hazards?
- -buildings fall -repercussions (landslides, liquefaction, fire, tsunami)
- Define: liquefaction
- solid material behaving (flowing) like a liquid
- Define: Parkfield Experiment
- in 1985 researches predicted that there was a 95% change of a magnitude 6. They were way off in time.
- Define: Lahars
- mixture of ash and water (melted snow), its like a flood
- Define: Shield Volcanoes looks/type of lava/eruption style
- -broad gently curved slopes -mostly basaltic lava flows -flows, very runny
- Define: Cinder Cones looks/type of lava/eruption style
- -cone shapped hills,several hundred meters high. Contain loose black or red pebble size volcanic cinders with larger volcanic bombs. -Basaltic -
- Define: Stratovolcanoes looks/type of lava/eruption style
- -large, nearly symmetrical volcanoes. Comes from a central vent -really explosive because the lava is andesitic or rhyolitic
- What are two examples of hot spots?
- Hawii and Yellowstone
- What are some volcanic hazards?
- lahar (ash and water) pyroclastic flow (mix of gas and solid ash. Lava behaves like a liquid)
- Famous Volcanoes
- -Mt. Vesuvius blew up Pompeii -Mt. St. Helens (largest recorded volcano in the US) -Yellowstone (everyone would be shit. Super Volcano) -Mt. Mazama (40X more powerful than Mt. St. Helens, created Crater Lake)
- Where are the North American Cordillera and the Castigate Range
- formed by oceanic crust being subducted by continental crust. Its goes all the way across the west cost of the USA
- General Overview of what happened to form the Southern Appalachians
- 1,000mya= supercontient 750mya= rifting of supercontinent 600mya= Iapetus Ocean (proto Atlantic) 500mya= subduction in Iapetus 460mya= piedmont terranies collide with NA 400mya= Godwana terranes collide with NA 300mya= Gondwana collides w/NA and forms Pangea 220mya= Pangea rifts apart
- What forms North Carolina
- Blue Ride+ Piedmont terrane+ Gondwanna terranes+ Costal Plain
- Define: Orogeny
- mountain building time period
- Define: Geologic window
- when older rocks are pushed over younger rocks. Then part of the older rocks erode away exposing younger rocks underneath
- What are the major mountain building processes?
- - Oceanic Oceanic subduction zones -Oceanic Continental subduction zone -Continental Continental collisions -Continental extension
- What is an example of: Oceanic Oceanic subduction zone?
- Aleution (Alaska) Japan arc
- What is an example of:Oceanic Continental subduction zone
- Cascade range in Washington
- What is an example of:Continental Continental collsion
- Heimlays
- What is an example of:Continental extension
- basin and range Nevada
- Define: Strike
- a horizontal plane bisection the rock (its where when you walk you don't go up or down)
- Define: Dip
- the direction the water falls