Geology Exam 1
tectonic plates move at rates that are approximately
1 to 15 cm/year
the Wadati-Benioff zone extends down within the mantle to a maximum depth of _____
660 km
the image below shows a view of a typical segmented mid-ocean ridge. what letter below marks the location of the active transform fault
B
which one of the pictures does NOT show a rock
D
the image below shows a cross-sectional view of a typical subduction zone, with earthquakes locations shown with small dots. the band of earthquakes that follow the shape of the downing plate is termed the
Wadati- Benioff zone
the internal ordering of mineral crystals can be detected using
X-ray diffraction
in the scope of plate tectonics, an active margin is defined as
a continental coastline that coincides with a plate boundary
minerals are all naturally occurring solid substances with a definable chemical composition. they also must possesses
a fixed crystalline structure (spatial arrangement of atoms and ions)
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
which of the following would NOT be considered a rock?
a natural pile of unconsolidated sand
cleavage in minerals refers to
a tendency to break along planes of weakness
the rate of the motion of a lithospheric plate with respect to a stationary location inside the Earth is termed ____. while the motion of a plate with respect to another is termed _____
absolute plate velocity; relative plate velocity
earthquakes occur most frequently near ________ margins
active
which of the following is NOT true about minerals
all mineral compounds of more than one element
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 subjected along with the lithosphere into the mantle
in a hot-spot volcanic island chain, such as the Hawaiian Islands, which of the following in NOT true?
all volcanos in the chain can be simultaneously active
the youngest sea floor is typically found _______
along mid-ocean ridges
a guyot is
an extinct ocean hot-spot that has subsided below sea level
Si04, S2-, and CO32- are all examples of ____
anions
of the ~4000 known minerals, the vast majority _____
are rare
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 is produced at shallow depths and gabbros at deeper depths
why is the rock cycle important
because it explains how rocks are constantly changing from one type to another
why do geologist classify rocks
because rocks are the key to determine how the Earth is formed
what does uplifting metamorphic rocks during mountain building lead to the formation of sedimentary rock
because the rocks become exposed to the elements and erode
with regard to minerals, hardness refers to the ability to resist
being scratched
which of the following is NOT a way for minerals to crystalize
bonding carbon to oxygen atoms to form organic compounds
identify which of the following paths could eventually transform a metamorphic rock into a sedimentary rock
burial -- meting -- erosion and deposition
the image below shows a mineral with hydrochloric acid applied to it. what mineral is this
calcite
diamond and graphite are both polymorphs of
carbon
calcite (CaCO3) is in which mineral class
carbonates
composition describes the
chemical makeup of a rock
minerals are grouped into mineral classes primarily on a basis of
chemistry, specifically the anions within the chemical formula
how is chloride different from chlorine
chloride has more electrons than chlorine
imagine if you are holding a rock composed of small sand grains cemented together. what sub classification of sedimentary rock is this
clastic
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 ____ amount individual crystals of this mineral
color
synthetically made glass and natural quartz crystals both exhibit a fracture pattern termed
conchoidal fracture
the image below shows a mineral specimen of quartz. 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 boundary type
convergent
subduction zones are found at which basic plate boundary type
convergent
the lithosphere of the Earth is generally thickest at and near _____ plate boundaries
convergent
which basic type of plate boundary is shown in the image below? (towards)
convergent
the volcanoes of the Cascade Mountains in the Northwest United States are related to melting of rock associated with a _____
convergent plate boundary
slab pull occurs because subjecting slabs are
cooler, and therefore more dense, than surrounding asthenosphere
what is the term used for the arrangement of the minerals in this picture
crystalline
what type of texture is shown int he photo micro graph
crystalline
which of the following is NOT one of the three major rock groups
crystalline
where would you expect to find metamorphic rocks forming
deep inside a mountain range
using the Mohs hardness scale below, which of the following statements is NOT true
diamonds are twice as hard as apatite
Under the theory of plate tectonics, the plates themselves are
discrete pieces of lithosphere at the surface of the solid Earth that moves with respect to one another
Iceland is on the of the few places in the world that is both above sea level and situated atop a ___ plate boundrary
divergent
the lithosphere of the earth is generally thinnest at ______ plate boundaries
divergent
which basic type of plate boundary is shown in the image below? (going away)
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 volcanos are absent
which of the following choices has particles ordered from smaller 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
granite is a type of rock that forms deep underground from magma that cools very slowly. what type of rock is granite
equant
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
the diamonds we typically see today in engagement rings do not display their natural crystal faces but rather _____, which are made by grinding the gem on a spinning lap
facets
minerals that do not possess cleavage are said to process
fracture
in which type of silicate are the greatest portion oxygen atoms shared by pairs pf adjacent tetrahedra
framework silicates
compared to typical oceanic lithosphere, the thickness of the 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, dense surrounding rock
consult the figure below, Hawaii is an example of ______
hot-spot volcanism
which of the following is a mineral
ice, which is water in the solid state
if a rock is buried and subjected to high heat and pressure, then uplifted, exposed, eroded away, and deposited, which type was NOT involved into the sequence
igneous
if a rock is buried, then exposed and eroded, and the sediment is then lithified, after which the rock is melted and cooled, what type of rock is the end result
igneous
what type of rock is being formed in this picture
igneous
what type of rock is formed during a volcanic eruption
igneous
what is the progression of rock types if the steps of a process are are followed: melting and cooling -- erosion and deposition -- burial
igneous -- sedimentary -- metamorphic
if a rock is melted, then erupted a the surface and cooled, then eroded and deposited, what two rock types are involved in the sequence
igneous and sedimentary
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 down going (subducting) 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
how would you tell if a rock is a crystalline
it contains interlocking crystals
what is the purpose of the cement surrounding the grains in this photo
it creates a coherent, intact rock
diamonds are usually founding pipes 50 to 200 m across made of
kimberlite
ore minerals, such as galena and hematite, tend to be different from typical minerals in that they have a
large specific gravity
the thickness of oceanic lithosphere is _______
last near the mid-ocean ridges and thickens away from the ridges
the way of a mineral scattered light is useful diagnostic property termed
luster
at a subduction zone, the overriding plate ______
may be composed of either oceanic or continental lithosphere
identify the correct steps to transform an igneous rock into a metamorphic rock then into an igneous rock
melted and cooled -- buried deep -- melted and ocoled
what must occur in order to create an igneous rock
melting
what process transforms a metamorphic rock into an igneous rock
melting
what process transforms a sedimentary rock into an igneous rock
melting
if a rock is subjected to high heat and pressure, a _____ rock will form
metamorphic
what type of rock is formed from deep burial
metamorphic
what type of rock is shown in this picture
metamorphic
what is the progression of rock types if the steps of a process are as followed: burial -- uplift, erosion, and deposition -- burial -- melting
metamorphic -- sedimentary -- metamorphic -- igneous
what do geologists call the layering seen in this picture
metamorphic foliation
igneous rock 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 tetrahedra may be chemically ponded to form all of the following EXCEPT
nearly perfect pyramid-shaped crystals
the atomic number of an element corresponds to the _____
number protons
a volcanic island arc forms when ____
oceanic lithosphere subjects 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 porcleain
minerals utilized by humans as a source of metal are termed ____ minerals
ore
the silica tetrahedron that forms the backbone of all the silicate minerals is composed of silicon and what other element
oxygen
continental coastlines that occur within the interior of a plate tectonic plate are called ____ margins
passive
broad, sediment- covered continental shelves are found along _____
passive margins
which common gemstone results from biomineralization
peral
which of the following is NOT a mineral
petroleum
hot-spots track resulting 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, the new solid particles are said to _____
precipitate from the solution
deformed (bent, stretched, or cracked). lithosphere occurs ______
primarily on the margins of tectonic plates
which of the following common minerals is hardest
quartz
the mid-oceanic ridges are elevated above the surrounding sea floor because
ridge rocks are hot and therefore have relatively low density
what is the name of the cycle shown in the picture
rock cycle
identify the correct steps in the transformation of a sedimentary rock into a metamorphic rock
rock eroded away and deposited in ocean basin -- rock bird under many layers of sediment
identify the correct steps in the transformation of an igneous rock to a metamorphic rock
rock melted and cooled -- rock subjected to high heat and pressure
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
if a rock is uplifted and exposed, what is the likely next type of rock that will form
sedimentary
what type of rock is formed after erosion, deposition, and lithification
sedimentary
what type of rock is shown in this picture
sedimentary
what type of rock would you expect to form from the material along a beach
sedimentary
which type of rock is formed by precipitation of minerals from a solution
sedimentary
what is the progression of rock types if the steps of a process are as followed: erosion and deposition -- melting -- melting -- erosion and deposition
sedimentary -- igneous -- igneous --sedimentary
potassium feldspar (KAIS3O8) is in which mineral class
silicates
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 (1.0 g/cm3)
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 for the thin parallel corrugations or stripes shown on the crystal faces below
striations
how does a metamorphic rock form
subject to a rock to high heat and pressure
pyrite (FeS2) is in which mineral class
sulfides
which of the following common minerals is softest
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
_____ is an example of a continental rift and the _____ is/are the result of collusion
the Basin and Range Province; Himalayan Mountains
oceanic lithosphere thickens away from the mid-ocean ridge primarily due to
the addition of new lithospheric mantle as a result of cooling
a triple junction, like the one shown below, is a place on Earth's surface where _____
the boundaries of all three lithospheric plates meet at a single point
geologists sometimes use analytical equipment to help identify rocks. one commonly used machine is the electron micropore, which focuses a beam of electrons on a sample to determine
the chemical composition
minerals in geodes from spectacular euhedral crystals because
the crystals have abundant room to grow in their hollow surroundings
according to Achimedes' 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 Precambrian rocks remained unchanged for billions of years
they are not protected within the interiors of the contents
the picture below shoes a ____ of rock that geologists use to determine the minerals in a rock
thin section
why do geologists use thin sections of rock
to identify the minerals
the San Andreas fault zone in California is an example of a _____ plate boundary
transform
which type of plate boundary is shown in the image below
transform
segments of mid-ocean ridge systems are offset. between the offset segments we observe _____
transform faults
hot spots can occur
within either continental or oceanic plates
