Shared Flashcard Set

Details

Geology Chapter 2
Chapter 2 of Earth: An Introduction to Physical Geology (10th)
34
Geology
Undergraduate 2
08/27/2013

Additional Geology Flashcards

 


 

Cards

Term
Continental Drift
Definition
A hypothesis that suggests that all present continents were once one main large formation that later broke apart and "drifted" from each other.
Term
Continental Rift
Definition
A linear zone along which continental lithosphere stretches and pulls apart. Its creation may mark the beginning of a new ocean basin.
Term
Continental Volcanic Arc
Definition
Mountains formed in part by igneous activity associated with the subduction of oceanic lithosphere beneath a continent. Examples include the Andes and the Cascades.
Term
Convergent Boundary
Definition
A boundary in which two plates move together, resulting in oceanic lithosphere being thrust beneath an overriding plate, eventually to be reabsorbed into the mantle. Can also come together to create mountain systems.
Term
Curie Point
Definition
The temperature above which a material loses its magnetization.
Term
Deep-Ocean Trench
Definition
A narrow, elongated depression of the seafloor.
Term
Divergent Boundary
&
Spreading Center
Definition
A boundary in which two plates move apart, resulting in upwelling of material from the mantle to create new seafloor.
Term
Fossil Magnetism
&
Paleomagnetism
Definition
The natural remnant magnetism in rock bodies.
Term
Fracture Zone
Definition
Linear zone of irregular topography on the deep-ocean floor that follows transform faults and their inactive extensions.
Term
Hot-Spot
Definition
A concentration of heat in the mantle.
Term
Hot-Spot Tracks
Definition
Chain of volcanic structures produces as a lithospheric plate moves over a mantle plume.
Term
Island Arc
&
Volcanic Island Arc
Definition
A chain of volcanic islands generally located a few hundred kilometers from a trench where there is active subduction of one oceanic plate beneath another.
Term
Lithospheric Plate
&
Tectonic Plates
Definition
A coherent unit of Earth's rigid outer layer that includes the crust and upper unit.
Term
Magnetometer
Definition
A sensitive instrument used to measure the intensity of Earth's magnetic field at various points.
Term
Magnetic Reversal
Definition
A change in Earth's magnetic field from normal to reverse or vice versa.
Term
Magnetic Time Scale
Definition
Time scale of Earth's magnetic field in the recent past. This time scale was developed by establishing the magnetic polarity for lava flows of known age.
Term
Mantle Plume
Definition
A mass of hotter-than-normal mantle material that ascends toward the surface, where it may lead to igneous activity. These plumes of solid yet mobile material may originate as deep as the core--- mantle boundary.
Term
Normal Polarity
Definition
A magnetic field the same as that which presently exists.
Term
Oceanic Ridge System
Definition
Winds through all of the major oceans in a manner similar to the seam on a baseball.
Term
Pangea
Definition
The proposed supercontinent that 200 million years ago began to break apart and form the present landmasses.
Term
Partial Melting
Definition
The process by which most igneous rocks melt. Since individual minerals have different melting points, most igneous rocks melt over a temperature range of a few hundred degrees. If the liquid is squeezed out after some melting has occurred, a melt with a higher silica content results.
Term
Plate Tectonics
Definition
The theory that proposes that Earth's outer shell consists of individual plates that interact in various ways and thereby produce earthquakes, volcanoes, mountains, and the crust itself.
Term
Reverse Polarity
Definition
A magnetic field opposite to that which presently exists.
Term
Ridge Push
Definition
A mechanism that may contribute to plate motion. It involves the oceanic lithosphere sliding down the oceanic ridge under the pull of gravity.
Term
Rift
or
Rift Valley
Definition
A long, narrow trough bounded by normal faults. It represents a region where divergence is taking place.
Term
Seafloor Spreading
Definition
The hypothesis, first proposed in the 1960s by Harry Hess, which suggested that new oceanic curst is produce at the crests of mid-ocean ridges, which are the sites of divergence.
Term
Slab Pull
Definition
A mechanism that contributes to plate motion in which cool, dense oceanic curst sinks into the mantle and "pulls" the trailing lithosphere along.
Term
Subduction Zone
Definition
A long, narrow zone where one lithospheric plate descends beneath another.
Term
Super Continent
Definition
A large landmass that contains all, or nearly all, of the existing continents.
Term
Transform Fault Boundary
Definition
A boundary in which two plates slide past one another without creating or destroying lithosphere.
Term
Moho Discontinuity
Definition
Small space between crust and Upper Mantle with different properties than both. Discovered by Mohorovic.
Term
Gutenberg Discontinuity
Definition
Small space between the Lower Mantle and Outer Core that has different characteristics from both. Discovered by Gutenberg.
Term
Plate Tectonics Theory
Definition
1. Continental Drift
2. Seafloor Spreading
Term
Plate Edge Interaction
Definition
1. Convergent (towards each other)
2. Divergent (away from each other)
3. Transform (sliding past each other)
Supporting users have an ad free experience!