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Geology Test #1
Geology Test #1
43
Science
Undergraduate 2
09/20/2011

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Cards

Term
Is the lithosphere just the crust? Crust and all of the mantle? Crust and part of the mantle?
Definition
The Lithosphere is the crust and just the upper mantle
Term
What is a typical plate motion rate?
Definition
2-7 cm p/yr
Term
At which type of plate boundary would you find a ridge?
Definition
Divergent
Term
At which type of plate boundary would you find a trench?
Definition
Convergent
Term
Which kinds of plate boundaries are associated with volcanic activity and which aren't?
Definition
Convergent and Divergent are
Term
What is a geographic example of each type of plate boundary? For example, where is subduction happening in the world today?
Definition
The mid Atlantic is an example of a Divergent plate boundary, OR the East African rift. (continental rifts are forming).

The San Andreas fault is an example of a Transform boundry

The Andes, Sierra Nevada, and Cascades mountains are an example of a Convergent boundary. (Plates collide and an ocean trench forms) (volcanic arcs form)
Term
What is the age of the sea floor?
Definition
0-180 mil years
Term
How does the age of the sea floor vary with distance from a mid-ocean ridge?
Definition
New magma is closest to the rift
Term
What is a hot spot? Where are some hot spots located?
Definition
A crack in the lithosphere and crust that spews magma, hawaii
Term
What is a mantle plume? How are plumes and hot spots related?
Definition
Warm rock that flows slowly upward beneath a hot spot. A mantle plume causes hot spots
Term
A chain of volcanic islands forms over a hot spot. Relative to the hot spot, where are the youngest and oldest islands in the chain?
Definition
The oldest island are farther away
Term
In what ways does volcanic activity near a subduction zone differ from volcanic activity at a hot spot?
Definition
Hot spots have high concentrations of basalt and other elements and have varied compsition as opposed to a uniform composition.
Term
Describe the pattern of normal and reverse magnetic anomalies on the sea floor near a mid-ocean ridge.
Definition
Normal: north magnetic pole is near the north magnetic pole and South
Reverse polarity: is opposite (happens every few million years)
Term
Why are the plates moving? Include the words “asthenosphere,” “heat transport,” “convection,” “ridge push,” and “slab pull” in your explanation.
Definition
Subduction of plates into the asthenosphere pull trailing plates “slab pull” with them. In ridge push, slabs of lithosphere slide down the ride. Convection flow in the mantle is the primary heat transport system, taking heat away from the earth’s interior to the surface, This is called convection
Term
What is “tectonics”?
Definition
Large scale processes affecting the structure of the earth’s crust
Term
How was Wegener’s continental drift hypothesis received by the scientific community at the time of its publication?
Definition
Harsh criticism, no one liked him
Term
Where has all of the old (>180 million year old) seafloor gone?
Definition
Its been lost to subduction back into the earth
Term
Is plate motion measurable today? Explain.
Definition
Yes, through GPS. May be measured using the length of a hot spot track and the time interval between formation of oldest and youngest volcanoes
Term
What is subduction?
Definition
The process that takes place at convergent boundries by which 1 tectonic plate moves under another plate, sinking into the earths mantle
Term
What are some geographic examples of hot spots?
Definition
Islands of Hawaii
Term
Which kind of volcanic rock is associated with mid-ocean ridges? Which kind(s) is/are associated with continental rifts? With continental hot spots? With oceanic hot spots?
Definition
Mid ocean ridges: Igneous
Term
What kind of volcanic rock is typical of a stratovolcano?
Definition
Andesite
Term
Where are most stratovolcanoes found?
Definition
A relatively narrow zone that rims the pacific ocean
Term
Are stratovolcanoes found near subduction zones?
Definition
Yes
Term
The Ring of Fire surrounds which ocean?
Definition
The Pacific Ocean
Term
What do vulcanologists monitor at a volcano which might (or might not) erupt?
Definition
Seismic activity
Term
The Asthenoshpere is part of the...?
Definition
Mantle
Term
True or False: Earth's early atmosphere had abundant amounts of oxygen
Definition
Term
The gasses that made up earths early atmosphere came from...?
Definition
Outgases from within
Term
True or False: Much of earths early atmosphere combined with iron dissolved in water to become iron oxide
Definition
True
Term
Which energy sources are thought to drive the lateral motions of earths lithosphereic plates?
Definition
Export of heat from deep within the mantle to the top of the asthenosphere
Term
A closed system is
Definition
energy that moves freely in and out but no matter enters nor leaves the system
Term
Crystal settling involves
Definition
crystals sinking to the bottom of a magma chamber
Term
A precious gem has
Definition
Beauty , durability and rarity
Term
True or False: Bowen's reaction series predicts the sizes of different mineral grains that grow from crystallizing magma
Definition
False!
Term
The mid atlantic ridge is...
Definition
Divergent
Term
Which was NEVER proposed as evidence supporting the existence of Pangea
Definition
Islands of Precambrian rocks along the mid atlantic ridge
Term
Which of the following statments apply to the asthenosphere and not the lithosphere
Definition
Zone in the Upper mantle that deforms by plastic flowage
Term
Order of the planets.....GO!
Definition
Sun --> Mercury --> Venus --> Earth --> Mars --> Asteroid Belt --> Jupiter --> Saturn --> Uranus --> Neptune
Term
Mount St. Helens and other cascade volcanoes are...
Definition
Young, active stratovolcanoes built on a continental margin above a sinking lab of oceanic lithosphere
Term
The volcanoes and deep valleys of East Africa are related to a...
Definition
continental rift along which parts of the african continent are beginning to slowly seperate
Term
The Red Sea is...
Definition
a logical evolutionary analog of the african rift valleys 10 million years old
Term
How many minerals are there?
Definition
about 4000
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