GLG Ch 3
docx
keyboard_arrow_up
School
Arizona State University, Tempe *
*We aren’t endorsed by this school
Course
GLG 101
Subject
Geology
Date
Apr 3, 2024
Type
docx
Pages
6
Uploaded by MasterMetalLyrebird39
CHAPTER 3: PLATE TECTONICS
1.
The surface of Earth is notable for many geologic features including intricate coastlines
, undersea trenches
, dramatic mountains
, and beautiful valleys
.
2.
There are 7
continents on Earth.
3.
The puzzle-like fit of the continents, similarity of rock types across continents, and glacial evidence all were pieces of evidence supporting Wegener's hypothesis of continental drift. What was another piece of supporting evidence?
○
Similar fossils are distributed across multiple continents
4.
Gondwana is the name given to the combination of southern continents
proposed by Wegener in his hypothesis of continental drift.
5.
Land bridges were originally proposed to explain fossil
evidence as provided by the presence of Mesosaurus and Glossopteris on continents separated by large oceans. One supercontinent that split apart by continental drift better explains this evidence.
6.
Earth's surface
is notable for many geologic features such as beautiful valleys, intricate coastlines, and deep ocean trenches.
7.
Glacial evidence in Southern
continents that are too warm for glaciers in their current position is evidence of continental drift.
8.
Using the figure, where are earthquakes most likely to occur?
○
Along continent edges and mid-ocean ridges
9.
Which pieces of evidence supported Wegener's hypothesis of continental drift?
○
Southern continental landmasses seem to fit together like puzzle pieces.
○
Fossils of animals and plants that existed more than 150 million years ago are present on several continents that are now divided by an ocean.
○
Similar rocks and geologic structures exist in South America, Africa, and Antarctica.
○
Glacial evidence exists in places that are now close to the equator, and the direction of glacial movement indicates the continents were once joined.
10. Geologists fit together the southern continents into the supercontinent Gondwana
.
11.
Which of the following statements are accurate about volcano distributions on Earth?
○
Volcanism occurs along mid-ocean ridges.
○
Many volcanoes along the edge of the Pacific Ocean are associated with earthquakes.
○
There is a large volcanic belt along the west coasts of North and South America.
12.
Scratch marks made on rocks in the southern continents by ancient glaciers
show that the continents were once connected around the South Pole and then moved apart by continental drift.
13.
Using the map (yellow circles represent earthquake locations and orange triangles represent volcano locations), which one of these is a better guide to plate boundaries on Earth?
○
Earthquakes
14.
Earthquakes are more common along the edges of continents and mid-ocean(ic)
ridges
15.
○
A → Divergent
○
B → Convergent
○
C → Transform
16.
Gondwana is the name given to the combination of southern continents
proposed by Wegener in his hypothesis of continental drift.
17.
○
Yellow → Divergent
○
Red → Convergent
○
Green → Transform
18.
Volcanoes and earthquakes often occur
in the same areas on Earth's surface.
19.
Which of the following is not a characteristic of a mid-ocean divergent boundary?
○
As the plates move apart, solid lithosphere moves upward into the asthenosphere.
○
Characteristics: A rift runs along the axis of mid-ocean ridges because of movement as the plates diverge from each other; Submarine lava flows form new ocean crust; Mid-ocean ridges are elevated above the surrounding seafloor
20.
The location of earthquakes is a better guide to plate boundaries
than the locations of volcanoes.
21.
When divergent boundaries occur on continents, the process is called continental
rifting.
22.
What two plate boundary types work together to define mid-ocean ridges?
○
Divergent ○
Transform 23.
When two plates move toward each other, convergent
boundaries are formed.
24.
Match the phrases to describe a mid-ocean ridge.
○
A rift is → located in the middle; it is a down-dropped area.
○
Magma is → created when rising asthenosphere melts due to decompression.
○
New ocean crust is → made from lava flows and solidification at depth.
25.
Along the boundary of an oceanic-continental convergence, the oceanic plate subducts beneath the continental plate
.
Oceanic plates subduct beneath continental plates because oceanic plates are dense and continental plates are buoyant
.
26.
Volcanoes that extend from the southwestern Pacific Ocean, through the Philippine Islands, Japan, and Alaska, then down the western coasts of the Americas form the Pacific Ring
of Fire.
27.
A divergent boundary can form within a continent. If it does it is called a continental rift
.
28.
The convergence of two continental masses is known as a continental collision
.
29.
Convergent boundaries are formed when two plates move toward each other
.
30.
The type of plate movement that occurs at transform faults is horizontal
.
31. Convergence of two ocean plates forms an ocean-ocean convergent boundary
.
32.
A fault that accommodates the horizontal movement of one tectonic plate past another is a(n) transform/strike-slip
fault.
33.
The Pacific Ring of Fire is formed by a string of volcanoes
.
34.
When two continental masses converge, we refer to it as a continental collision
.
35.
A triple junction is a place where three plate boundaries meet
.
36.
Select the statement that best describes how the process of plate tectonics circulates materials between the asthenosphere and the lithosphere.
○
Some asthenosphere becomes lithosphere at mid-ocean spreading centers and reenters the asthenosphere at subduction zones.
37.
For a plate to move, the driving forces must exceed the resisting/opposite/opposing
forces.
38.
Plates move 1 to 15 cm
per year.
39.
Which tools do we use to directly measure plate motion?
○
Lasers ○
GPS satellites
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
40.
The boundary between two plates may not have the same characteristics in different geographic locations because of curves and abrupt bends that appear in boundaries between plates
.
41.
The process of plate tectonics circulates materials between the asthenosphere and the lithosphere
.
42.
In order for a tectonic plate to move, what must the relationship between driving and resisting forces be?
○
The driving forces must exceed the resisting forces
43.
The layer of Earth that behaves as a dynamo (electrical generator), producing the magnetic field, is the outer core
.
44.
The yearly rate of tectonic plate movement is best measured in centimeters
.
45.
GPS and lasers are used to directly measure the motion and direction of tectonic plates
on Earth.
46.
Plate boundaries cover a surface that is spherical
so they are curved
and subsequently can change from one type to another, e.g., from transform to convergent
47.
Earth’s magnetic
poles have switched many times throughout geologic history.
48.
Convection currents in Earth’s outer/liquid/molten
core produce the magnetic field.
49.
Magnetic patterns develop on the seafloor as basaltic lava erupts and cools, and iron-rich minerals align with Earth's magnetic field
.
50.
Using the drill cores shown on the diagram, which areas of the ocean floor are the oldest?
○
The extreme left and right cores
According to plate tectonics, oceanic crust forms from upwelling magma that spreads outward from a mid-ocean ridge. Which of the following statements support this?
○
If this is true, the thickest sediment cover should be farthest from the mid-ocean ridge.
○
If this is true, then the oldest basalt should be the farthest from the mid-ocean ridge.
51.
Both the matching of continent(al)
outlines and their geology help to support the theory of plate tectonics
.
52.
How many times did Earth's magnetic field switch in the last 10 million years?
○
Many–more than 40 times
53.
Island chains and seamounts cross parts of the ocean floor. In terms of plate tectonics, these oceanic islands and associated seamounts are different in character and origin from curved island arcs
.
54. As iron-rich minerals in newly erupted basaltic lava align with Earth's magnetic poles, magnetic/striped
patterns develop on the seafloor.
55.
The western margin of South America is mountainous
, whereas the eastern margin has much less relief, which reflects
the different tectonic plate settings that surround the continent.
56.
Continental outlines and similar geology on neighboring continents support the theory of plate tectonics
.
57.
Compare the tectonic settings of western and eastern South America by placing the features in the correct category.
○
Western side → Trench, mountains, subduction zone
○
Eastern side → Wide continental shelf, passive margin, more subdued topography
58.
Earthquakes are common along the western coast of South America as a subduction
zone occurs due to oceanic lithosphere moving beneath the continent.
59.
True or false
: Curved island arcs and linear island chains are very similar in their character and formation.
60.
The figure shows the movement of South America
over time to its current position.
61.
The eastern side of South America lacks mountains
compared to the western side; this demonstrates the two areas have drastically different plate tectonic settings.
62.
What is the underlying geologic explanation for why western South America is so different from eastern South America?
○
The western side is a plate boundary and the eastern side is not.
63.
The arrow in the figure is pointing to the Mid
-Atlantic
Ridge
, where the African and South American plates are moving apart and new oceanic lithosphere is emerging from Earth's mantle.
64.
South America has been moving away from
Africa for the past 140 million years.
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help