Chapter 2: Geology Flashcards
The study of the earth
Geology
The 3 major layers of the earth based on composition
Crust, mantle, and core
Outer layer of the earth made of solid rock
Crust
Deposits of sand, mineral fragments, or organic materials usually left by wind or water that can be found in the earth’s crust
Sediments
The most abundant element in the earth’s crust
Oxygen
Type of crust composed of granite (silica and aluminum oxide)
Continental crust
Type of crust composed of basalt and gabbro
Oceanic crust
Middle layer of the earth
Mantle
Earthquake vibrations used to determine what lies beneath the earth’s crust
Seismic waves
Lower boundary of the crust that marks the change in rock density within the earth (Hint: Croatia)
Moho, or Mohorovičić discontinuity
The first person to use seismic waves to map the earth’s interior
Andrija Mohorovicic
The middle layer of the earth
Mantle
The area between the upper and lower mantle that marks where the two portions merge
Transition zone
The rocks of the mantle that flow more like a thick, syrupy liquid in slow motion
Plastic rock
The deeper you go in the earth, the ____________ the temperature becomes.
Higher
The lower boundary of he mantle that marks yet another change in the earth’s density
Core-mantle boundary, or Gutenberg discontinuity
The central part of the earth
Core
Layer of the core that is assumed to be composed of molten (liquid) iron and nickel
Outer core
Layer of the core that is assumed to be composed of solid iron and nickel
Inner core
Portions of solid rock that float like rafts on the plastic rock of the upper mantle
Tectonic plates
A region of the earth’s crust and upper mantle composed of rigid plates
Lithosphere
The plastic rock hat forms the lower portion of the upper mantle
Asthenosphere
Theory that the plates and their movements affect geologic structures and processes
Plate tectonics
The fracture zone that results from layers of rock breaking and moving due to the strain of forces upon it. The boundary between stationary rocks and moving rocks
Fault
Type of fault that occurs when rocks along one side of a fault sink vertically (often results in cliffs)
Normal fault
Type of fault that occurs when rocks along one side of a fault move horizontally along a fault
Strike-slip fault
Type of fault caused by rocks on one side of a fault being shoved on top of the rocks on the other side.
Thrust fault
The result of the bending or buckling of rock under great force
Fold
Rocks that bend downward in the folding process for a trough-like structure called a ____________.
Syncline
Rocks that buckle upward during folding form an arch-like structure called a(n) ________________.
Anticline
Elevated land masses that are higher than hills
Mountains
Formed when molten rock erupts from the earth’s crust
Volcanic mountains
Formed when molten rock is formed beneath an overlying rock layer, forcing that rock layer upward into a blister like shape
Domes mountain
Formed when the edges of two adjacent tectonic plates were pushed together, causing the layers to buckle
Folded mountains
Formed when rocks along one side of a fault are forced upward while the rocks on the other side sink
Fault-block mountain
Maps that show an area’s elevation, natural features, and man-made structures
Topographic maps
A computer system that stores and processes geographic data
Geographic information system (GIS)
Earthquakes that result from the sudden movements of rock beneath the earth’s surface
Tectonic earthquakes
A weak earthquake
Tremor
Smaller earthquakes or tremors
Aftershocks