Chapter 2- Geology Flashcards
What is the study of the earth?
Geology
What is the outer layer of the earth’s surface called?
The crust
What is most of the earth covered with?
Organic Material which is sediments
What is the most abundant element in the earths crust?
Oxygen
What is the second most abundant element in the crust?
Silicon
What’s the name of the region that marks the lower boundary of the crust?
The Moho
Beneath the Moho lies which layer of the earth?
The mantle
We have the Moho then we have the mantle, what’s below the upper mantle?
The transition zone
What’s below the transition zone?
The lower mantle
What is the central part of the earth called ?
The core
The inner core is a solid core, what do geologists think it’s made of?
Nickel and iron
Name the theory where eight large plates float on plastic rock of the mantle
The plate tectonics theory
Why do you think that the tectonic plates float?
Convection currents moving currents within the mantle how the heat rises and how it sinks then it drops
All the continents were connected to each other into one huge land mass called what?
Pangaea
Name the fault that sinks vertically
Normal fault
Which fault at when one side of rocks are shoved on top of the rocks on the other side?
Thrust fault
How does the strike-slip fault move
Horizontally
What’s the difference between a fault and a fold
A fault is a break and a fold is a bend
What do we call the folding process when rocks bend downward in a trough like structure
A syncline
Name the type of mountain that forms when molten rock erupts from a hole in the earths crust
Volcanic mountain
What type of mountains appear to form when molten rock is forced beneath an overlying rock layer
a domed mountain
What type of mountain is formed when the edges of two adjacent rock layers are pushed together causing the rocks to buckle
Folded mountains
Name the type of mountains that have formed along a fault where the rocks on one Side of the fault are forced upward while the rocks on the other side sink
Fault block mountains
What is the arch like structure formed when rocks are folded up word
Anticlines
Name the most active earthquake zone
The circum pacific belt
Earthquakes that result from sudden movements of rock beneath the earth surface are called what?
Tectonic earthquake
What percent of earthquakes occur in the circum pacific belt?
80%
What is seismology
The study of earthquakes
Name this theory what is the theory that states that rocks on either side of the fault spring back into position of little or no strain at the moment of an earthquake
The elastic rebound theory
Name the famous strike slip fault in western California
The San Andreas Fault
What is the point of which an earthquake begins
The focus
What do we call the place where the earthquake is most severe
The epicenter
What is the fastest kind of seismic wave
The P-wave
Seismologist study the vibrations caused by earthquakes using instrument called the what?
Seismograph
Small earthquakes often follow a large earthquake at frequent intervals for days months or years
Aftershocks
Name the most famous scale that measures strength
The Richter scale
Buildings constructed on bed rock are called what?
Fixed base Systems
What is the problem with fixed based systems?
The buildings become deformed
What is the most common new construction where buildings rest on isolators and it absorbs the seismic energy
Based Isolated systems
What are devices added to structures to absorb some of the seismic energy
Energy dissipating devices
Name the first type of cone volcano that consists primarily of volcanic ash or rock fragments
Cindercone volcano
Name a volcano that is made from large quantities of highly fluid lava and rather mild erruption‘s
Shield volcano
What do we call the source of volcanic irruption’s
The magma chamber
What is magma
Molten rock
Name the volcano that produces both cinderss and lava
composite volcano or stratovolcanoes
What are we call an inactive volcano that could irrupt again
Dormant volcanoes
A volcano that has erupted within recorded history or is currently producing seismic energy/activity is considered a
Active volcano
More than half of active volcanoes can be found in this belt in the Pacific basin
The ring of fire
What do we call lava that hardens into rough jagged rocks with a crumbly or blocky texture
aa
What do we call lava that hardens into a smooth textured rock with a ropy appearance
Pahoehoe
What do we call a particle or block of solid volcanic ejecta
pyroclasts
What do we call superheated cloud of gas and volcanic ash that travels down the slope as an avalanche
Pyroclastic flow
What are huge Bowl shaped craters that occur when a magma chamber empties then collapses
calderas
What are almond shaped or teardrops shaped pieces of ejecta formed when lava hardens in the air
Volcanic bombs
What do we call a domed like igneous intrusion formed when magma bulges overlying rocks
Laccolith
What is a sheet like igneous intrusion formed when magma hardens in a vertical crack
Dike
Name an underground channel that forms when surface lava hardens before the lava underneath
Lava tunnels
