ESC 1000C - chapter 2
According to the image below, where is new oceanic crust being formed?
A
The image below shows a view of a typical segmented mid-ocean ridge. Which letter below marks the location of the active transform fault?
B
A geologist aboard a deep-sea research vessel has collected several drill cores of oceanic crust from the bottom of the ocean. The cores are collected in order from east to west along the bottom of the basin and are labeled A1, B1, C1, and D1, respectively. Core A1 has 2.88 meters (m) of clay and siliceous ooze covering 4.86 m of pillow basalt. Core B1 has 2.37 m of muddy, clay ooze covering 3.57 m of basalt. Core C1 has 2.11 m of clay and siliceous ooze above 3.2 m of basalt. Core D1 has 1.87 m of siliceous ooze over 2.54 m of basalt. Which core is closest to the mid-ocean ridge?
D1
Which of the following is MOST true of the lithosphere?
It is composed of the crust and uppermost part of the mantle.
Consult the figure below. Abundant swamps led to the formation of coal during the Late Paleozoic in which of the following places?
North America
What would happen if the rate of seafloor spreading was faster than the rate of subduction?
The Earth would grow larger.
Which of these parts of the deep-ocean floor is flat and nearly featureless?
abyssal plain
Seafloor spreading is driven by volcanic activity
along mid-ocean ridges
Beneath a blanket of sediments, oceanic crust is primarily composed of
basalt.
The Himalayan Mountains are the result of
continental collision.
Which basic type of plate boundary is shown in the image below?
convergent
Subduction zones occur at
convergent boundaries.
Slab pull occurs because subducting slabs are __________ and therefore __________ than surrounding asthenosphere.
cooler; more dense
seafloor spreading
creates new oceanic crust.
The density of rocks in Earth's layers is generally related to composition. Which of the following choices places compositions in order of increasing density?
crust, mantle, core
Under the theory of plate tectonics, the plates themselves are
discrete pieces of lithosphere at the surface of the solid Earth that move with respect to one another.
Seafloor spreading occurs at __________ boundaries
divergent
Which basic type of plate boundary is shown in the image below?
divergent
Seafloor spreading is MOST likely to occur at
divergent boundaries
Transform boundaries occur MOST commonly perpendicular to __________ boundaries in order to break the __________ into segments so as to accommodate motion on a sphere.
divergent; mid-ocean ridges
The distribution of __________ across the globe provides the primary indicator of boundaries between all tectonic plates.
earthquakes
At transform plate boundaries,
earthquakes are common but volcanoes are absent
Compared with typical oceanic lithosphere, the thickness of continental lithosphere is
greater.
Regions of the seafloor with positive magnetic anomalies were formed during times when Earth's magnetic field
had normal polarity.
Hawaii is an example of
hot-spot volcanism
Compared with the crust, the mantle is __________ and __________ able to flow
hotter; more
With increasing distance from a mid-ocean ridge, the age of oceanic crust
increases.
During a journey to the center of Earth, one would experience temperature __________ and pressure __________.
increasing; increasing
The densest layer of Earth is the
inner core
Unlike the lithosphere, the asthenosphere
is able to flow over long periods of time
At a subduction zone, the down-going (subducting) plate
is always composed of oceanic lithosphere.
In the geologic past, the polarity of Earth's magnetic field is
known to have experienced numerous reversals, as shown by remnant magnetization of iron-rich minerals in rocks.
The thickness of oceanic lithosphere is
least near the mid-ocean ridges and thickens away from the ridges
As compared to basalt, granite has a
lower density
Molten rock beneath Earth's surface is termed
magma
Continental coastlines that occur within the interior of a tectonic plate are called __________ margins.
passive
In general, the mantle is made of the rock
peridotite.
According to the figure below, marine magnetic anomalies lay roughly __________ to mid-ocean ridges.
perpendicular
The theory of __________ states that the lithosphere is broken into a series of plates that move relative to each other.
plate tectonics
Deformed (bent, stretched, or cracked) lithosphere occurs
primarily on the margins of tectonic plates.
Marine magnetic anomalies can be used to estimate the
rate of seafloor spreading
Geologists are able to study Earth's interior primarily using
seismic waves
Which of the following was NOT used as evidence by Alfred Wegener to support his theory of continental drift?
seismic waves
Globally, the rate of seafloor spreading takes place at the same rate as
subduction
The primary difference between lithospheric and asthenospheric mantle that gives rise to numerous different patterns of physical behavior is
temperature: the lithosphere is cooler than the asthenosphere.
If a geologist discovered coal in a modern-day cold, snowy location, he or she could conclude that
the area was once covered with swamps and/or jungles.
Younger oceanic crust will have __________ ocean sediments, whereas older oceanic crust will have __________ oceanic sediments
thinner; thicker
Measuring the elevation of a mountain means measuring variation in __________, whereas doing the same on a mid-ocean ridge would be measuring variation in __________.
topography; bathymetry
In Wegener's evidence for continental drift, continents were proposed to fit together, such as the east coast of South America with the
west coast of Africa.
Hot spots can occur
within either continental or oceanic plates