Geology 103 Exam 1 Prep Questions
Tectonic plates move at rates that are approximately ____________.
1 to 15 cm/year
the wadati-benioff zone extends down with in the mantle to a maximum depth of _______?
660km
which of the following is NOT true about minerals
All minerals are compounds of more than one element.
how is chloride different from chlorine
Chloride has more electrons than chlorine
how would you tell if a rock is crystalline?
It contains interlocking crystals.
what type of rock is formed from a deep burial
Metamorphic
in the scope of plate tectonics, an active margin is defined as
a continental coastline the coincides with a plate boundary
Minerals are naturally occurring solid substances with a definable chemical composition. They must also possess _____.
a fixed crystalline structure
which of the following is not true concerning the color of minerals
a mineral's color reflects the wavelengths of light that are absorbed by the mineral
Cleavage in minerals refers to ____________.
a tendency to break along planes of weakness
The rate of motion of a lithospheric plate with respect to a stationary hot spot is termed ____________.
absolute plate velocity; relative plate velocity
eathquakes occur most frequently near ____ margins
active
the oceanic lithosphere is typically coated in a layer of sediment. Which of the following is NOT true about this sediment
all of the sediment is eventually subducted along with the lithosphere into the mantle
in a hot-spot volcanic island chain, such as the Hawaiian islands which of the following is not true?
all volcanoes in the chain can be simultaneously active
the youngest sea floor typically found ______
along mid-ocean ridges
a guyot is
an extinct oceanic hot-spot volcano that has subsided below sea level
of the ~4,000 known minerals, the vast majority
are rare
Most of the pushing force driving plate motion is produced
at mid-ocean ridges
most of the pushing force driving plate motion is produced ______?
at mid-ocean ridges
Most of the pulling force driving plate motion is produced ________.
at subduction zones
which of the following statements is true concerning rock produced at mid-ocean ridges
basalt at shallow gabbro at deeper
why do geologist classify rocks?
because rocks are the key to determining how the earth formed
with regards to minerals, hardness refers to the ability to resist
being scratched
which of the following is not a way for minerals to crystallize
bonding carbon to oxygen atoms to form organic compounds
the image below shows a mineral with hydrochloric acid applied to it. what mineral is this?
calite
Diamond and graphite are both polymorphs of
carbon
Minerals are grouped into mineral classes primarily on a basis of ________.
chemistry, specifically the anions within the chemical formula
when two plates composed of continental lithosphere are pulled together at a convergent boundary the result is
collision and mountain formation
Trace amounts of impurity in a mineral can commonly produce significant differences in ____________ among individual crystals of this mineral.
color
synthetically made glass and natural quartz crystals both exhibit a fracture pattern termed
conchoidal fracture
what is the term for the smoothly curving, clamshell-shaped surface on the sample below?
conchoidal fracture
Large, thick-crusted, nonvolcanic mountain belts, like the Himalayas, are associated with ________.
continent-continent collisions
Deep oceanic trenches are features of ____________ plate boundaries.
convergent
subduction zones are found at which basic plate boundary ?
convergent
the lithosphere of the earth is generally thickest at and near _______ plate boundaries?
convergent
what basic type of plate boundary is shown in the image below?
convergent
the volcanoes of the Cascades Mountains in the northwest US are related to melting of rock associated with a ______?
convergent plate boundary
Slab pull occurs because subducting slabs are
cooler, and therefore more dense, than surrounding asthenosphere
which of the following is not one of the three major rock grousp
crystalline
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
Iceland is one of the few places in the world that is both above sea level and situated atop a ____________ plate boundary.
divergent
Which basic type of plate boundary is shown in the image below?
divergent
the lithosphere of the earth is generally thinnest at _____ plate boundaries
divergent
mid-ocean ridges are segmented and contain which two basic types of plate boundaries linked together?
divergent and transform
Natural glass is not considered a mineral because it ____________.
does not have a fixed crystalline structure
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
which of the following choices have particles ordered from smallest to largest in size?
electron, proton, nucleus, atom
Summed over the entire surface of Earth, the rate of spreading at divergent boundaries is ________ lithospheric consumption at subduction zones.
equal to
in order to form a sedimentary rock, what process must happen
erosion
what process must occur for an igneous rock to turn into a sedimentary rock
erosion
Gemstones are commonly found in pegmatites, which are igneous rocks that are ____________.
exceptionally coarse grained
Minerals that do not possess cleavage are said to possess ____________.
fracture
in which type of silicate are the greatest proportion of oxygen atoms shared by pairs of adjacent tetrahedra
framework silicates
compared to typical lithosphere, the thickness of continental lithosphere is
greater
which of the following minerals is more commonly known as table salt
halite
according to the model proposed by geophysicist J. Tuzo Wilson, hot spots are caused by __________?
hot plumes of mantle material that rise up through cooler, denser surrounding rock
which of the following is a mineral
ice, which is water in the solid state
what type of rock is formed during a volcanic erruption
igneous
what type of rock is granite
igneous rock
the theory of plate tectonics
incorporates and explains both sea-floor spreading and continental drift
Unlike the lithosphere, the asthenosphere
is able to flow over long periods of time
At a subduction zone, the downgoing plate ____?
is always composed of oceanic lithosphere
continental lithosphere
is thicker than oceanic lithosphere
the lithosphere of earth will not flow because it
is too cool
Diamonds are usually found in pipes 50 to 200 m across made of _____________.
kimberlite
Ore minerals, such as galena and hematite, tend to be distinct in their very ____________.
large specific gravity
The thickness of oceanic lithosphere is _____.
least near the mid-ocean ridges and thickens away from the ridges
The way a mineral scatters light is a useful diagnostic property termed
luster
at a subduction zone, the overriding plate ______?
may be composed of either oceanic or continental lithosphere
What process transforms a metamorphic rock into an igneous rock?
melting
what process transforms sedimentary rock into an igneous rock
melting
If a rock is subjected to high heat and pressure, a(n) _______________ rock will form.
metamorphic
Igneous rocks form from
molten rock cooling and forming crystals
what must happen in order to transform a metamorphic rock into a sedimentary rock?
mountain building
The single property that can be used to identify any mineral is ____________.
multiple properties must be used to identify a mineral
in silicate minerals, silica tretrahedra may be chemically bonded to form all of the following expect
nearly perfect pyramid-shaped crystals
Atomic number of an element
number of protons
a volcanic island arc forms when
oceanic lithosphere subducts beneath another oceanic lithospheric plate
The most recently formed portion of any crystal is always found ________.
on the outer edges
For the majority of minerals, the streak color obtained when the mineral is scratched against a porcelain plate is ________.
only useful if the mineral is softer than porcelain
Minerals utilized by humans as a source of metal are termed ________.
ore
the silica tetrahedron that forms the backbone of all silicate minerals is composed of silicon and what other elements?
oxygen
Broad, sediment-covered continental shelves are found along ____________.
passive margins
Continental coastlines that occur within the interior of a tectonic plate are called
passive margins
Which common gemstone results from biomineralization?
pearl
which of the following is NOT a mineral
petroleum
Hot-spot tracks result from moving
plates
when two different minerals have the same chemical formula but different crystal structures they are said to be
polymorphs
When a solution becomes oversaturated, new solid particles are said to ________.
precipitate from the solutions
Deformed (bent, stretched, or cracked) lithosphere occurs
primarily on the margins of tectonic plates
which of following common minerals is the hardests
quartz
the mid-ocean ridges are elevated above the surrounding sea floor because
ridge rocks are hot and therefore have relatively low density
which is a characteristic used to classify a rock?
rock texture
Which two gems are special versions of the common mineral corundum (Al2O3)?
sapphires and rubies
what type of rock is formed after erosion, deposition, and lithification
sedimentary
what type of rock would you expect to form from the material found along a beach?
sedimentary
which type of rock is formed by precipitation of minerals from a solution
sedimentary
The mineral class that makes up >95% of the continental crust is termed the ________.
silicates
on either side of a mid-ocean ridge, the lithosphere begins to
sink because it cools and contracts
which of the following is NOT true about earth's tectonic plates
some tectonic plates contain only continental lithosphere
_________ is a mineral property defined by the density of the mineral sample divided by the density of water
specific gravity
the color of a mineral in powdered form is termed
streak
the image below shows a mineral specimen of pyrite. what is the term or the thin parallel corrugations or stripes shown on the crystals face
striations
How does metamorphic rock form?
subject a rock to high heat and pressure
which of the following common minerals is softests?
talc
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
Oceanic lithosphere thickens away from the mid-ocean ridge primarily due to ________.
the addition of new lithospheric mantle as a result of cooling
_______ is an example of a continental rift and the __________ is/are the result of collision
the basin and range province; himalayan mountains
A triple junction, like the one shown below, is a place on Earth's surface where ____________.
the boundaries of three lithospheric plates meet at a single point
composition describes the __________
the chemical makeup of a rock
Minerals in geodes form spectacular euhedral crystals because
the crystals have abundant room to grow in their hollow surroundings
According to Archimedes' principle of buoyancy, an iceberg sinks until ________.
the total mass of the water displaced equals the total mass of the whole iceberg
what is the rock cycle
the transformation of one rock type to another
why have many precambrain rocks remained unchanged for billions of years
they are protected within the interiors of the continents
Which basic type of plate boundary is shown in the image below?
transform
the san andreas fault zone in Cali is an example of a __________ plate boundary
transform
Segments of the mid-ocean ridge system are offset. Between the offset segments we observe ____________.
transform faults
Hot spots occur
within either continental or oceanic plates