Geology Final Study
How many elements compose the majority of rock-forming minerals?
8
The process by which ions arrange themselves into orderly patterns during the cooling of a liquid is called
Crystallization
In 1980, _____________ was the first Cascade Range volcano to erupt since Mt. Lassen in 1915-16.
Mt. St. Helens
which was the most powerful explosive volcanic eruption of historic time
Tambora, Indonesia, 1815
which of the following is an example of a tabular intrusive body
a dike
which of the following grain characteristics does not provide information about how far sediments have been transported
cement
tension results in what changes to earth's crust?
lengthening
T or F: tectonic plates are comprised of continental crust or oceanic crust, but never both
false
____ rocks are composed almost entirely of light-colored silicates
felsic
partial melting results in a magma that is nearer the ____ end of the compositional spectrum than the parent rock from which it was derived
felsic
which of the following would you most expect to accompany an eruption of kilauea volcano in hawaii
fluid lava flows
two primary types of metamorphic rocks
foliated and unfoliated
what is the most common form of physical weathering
frost wedging
what is the principle of uniformitarianism
geologic processes that are seen today are the same as those that acted in the past
when magma cools too fast for mineral grains to grow the resultant texture is called
glassy
the mohs scale measures which property of minerals
hardness
which is not a form of deformation?
horizontal, flat laying strata
the ____ is the 3-D place where a fault has actually slipped on the fault plane
hypocenter
______ rocks form by crystallization and consolidation of molten magma
igneous
why do earthquakes at convergent plate boundaries stop below 660km?
increases in the earth's geothermal gradient reduce friction and allow ductile flow
physical weathering augments (helps) chemical weathering by doing what?
increasing the surface area over which chemical weathering can occur
____ minerals can be used to understand the very specific temperature and pressure conditions under which a rock was metamorphosed
index
In correct order from the center outward, Earth includes which units?
inner core, outer core, mantle, crust
which of the following describes the light reflecting characteristics of a mineral
luster
___ minerals are less stable while ___ minerals, quartz especially, are more resistant to chemical weathering
mafic felsic
Which of the following is most likely to result in an effusive eruption?
magma with a low silica composition
how does one classify a non silicate mineral group
negatively charged ion or complex ion
an erosional surface between igneous or metamorphic rocks and overlying sedimentary rocks
nonconformity
mineral resources are ___ resources
nonrenewable
The most prominent feature on the ocean floor are the ____
ocean ridges
andes mountains is an example of which kind of convergent boundary?
ocean-continent subduction zone
exfoliation jointing occurs because ____ [UNSURE]
of a decrease in confining pressure when a batholith is exhumed
which of the following minerals crystallize early in bowen's reaction series
olivine
The ___ is thought to be a liquid, metallic region in the Earth's interior
outer core
what are the fastest seismic waves to arrive at a seismic station after an earthquake?
p-waves
the c-horizon is defined as which of the following?
partially altered parent material
____, a mafic rock comprised almost exclusively of olivine, is thought to be common in the earth's mantle but rare in the crust
peridotite
a(n) ____ texture represents a single long period of cooling and crystallization
phaneritic
another word for a coarse-grained texture is
phaneritic
The large mineral grains in a porphyritic igneous rock are called ____
phenocrysts
a lava flow comprised of numerous blob-like structures is called _____
pillow lava
which term describes a rock with large crystals embedded in a matrix of smaller crystals
porphyritic
the ___ division of the geologic time scale makes up over 88 percent of geologic time
precambrian
What is the correct definition of a protolith?
preexisting rocks before they were metamorphosed
________ denote positively charged, nuclear particles.
protons
_____ is a volcanic rock that is extremely vesicular and glassy.
pumice
____ is a dangerous fast moving hot turbulent cloud of volcanic gases and fine-sized pyroclastic particles
pyroclastic flow
a sedimentary rock made primarily of which mineral would be considered the most mature
quartz
which mineral is composed of only silicon dioxide (sio2)
quartz
which one of the following shows the correct order of decreasing magma viscosity
rhyolite, andesite, basalt
which of the following igneous rocks has a pyroclastic texture
rhyolitic tuff
what is the mechanism that explains the movement of tectonic plates
sea-floor spreading
the law of original horizontality says
sedimentary layers were initially deposited horizontally in aqueous environments
the principle of lateral continuity says that
sediments forming strata were originally deposited in regionally extensive horizontal sheets
the more ____ in a magma the more its viscosity increases
silica
which group of minerals are the most abundant in the earth's crust
silicates
All silicate minerals contain which two elements?
silicon and oxygen
A ______ is an open cavity in a volcanic rock that was filled by a gas bubble when the lava was still mainly liquid
vesicle
when gas bubbles escape as lava solidifies a ___ texture is formed
vesicular
___ is a major dissolved volatile constituent in both magmas and volcanic gases
water
___ is often paraphrased as the present is the key to the past
uniformitarianism
in a reverse fault, the hanging wall moves ___ relative to the foot wall
up
in a thrust fault, the hanging wall moves ___ relative to the foot wall
up
Changing the composition of magma by incorporating surrounding host rock is known as ________.
Assimilation
________ has the same mineral composition as andesite.
Diorite
____ is the name given to molten rock when it reaches Earth's surface
Lava
why do magmas rise toward earth's surface
Magmas are mainly liquid and contain dissolved fluids such as water; most are less dense than the adjacent solid rock.
Which of the following minerals is a silicate? Muscovite Halite Hematite Calcite
Muscovite
Compared to the age of Earth accepted as correct today, how did 17th and 18th century proponents of catastrophism envision the Earth's age?
They believed Earth to be much younger than current estimates
which type of basaltic lava flow has its surface covered with sharp-edged angular blocks and rubble
aa
the oldest portions of the sea floor are located where
along passive continental margins
which best describes the way composite volcanoes are built up
alternating layers of cinders and ash embedded with lava flows
Mount St. Helens is ____
an explosive stratovolcano
an erosional surface between underlying tilted or folded sedimentary rock and overlying sedimentary rock
angular unconformity
according to the rock cycle which of the following statements is true
any rock type can ultimately be turned into any other rock type
you come across a whitish mineral in the field you think it might be calcite, but you aren't sure. which of the following would be the best way to determine if your sample is calcite
apply dilute hydrochloric acid to see if it fizzes
What is the smallest particle of matter that exhibits and defines the distinctive chemical characteristics of the individual elements
atom
___ is the dominant lava erupted from volcanoes on hawaii and iceland
basalt
oceanic crust is made primarily of...
basalt
which igneous rock or magma has the least amount of light-colored silicates
basalt
____ magma is the most abundant type of erupted at oceanic spreading centers
basaltic
kilauea and mauna loa (hawaii) are ____
basaltic shield volcanoes
___ are the largest intrusive igneous bodies
batholiths
the ___ refers to the sum total of all life on earth
biosphere
talus slopes are characterized by ___ and are a product of ____
blocky angular rock fragments frost wedging in mountainous regions
slickenslides are evidence of what kind of movement/deformation along a fault?
brittle deformation
___ are large circular depressions having diameters greater than 1 km across
calderas
large volcanic depressions formed by subsidence and collapse are known as
calderas
which of the statements below is NOT TRUE about the relationship between chemical weathering and climate
chemical weathering maintains earth's climate system through silicate mineral weathering
The strong tendency of certain minerals to break along smooth, parallel planes is known as _____
cleavage
what is the most important factor in determining the type of weathering a geologic material will undergo
climate
what are the two most important factors in soil formation
climate and parent material
the himalaya mountains are the result of what type of process
continent-continent collision
basaltic lava flows are generally ___ and ___ than andesite lavas
cooler, less viscous
which principle tells us that a dike cutting across a sandstone unit is younger than the sandstone?
cross-cutting relationships
thinnest layer of the earth
crust
all of the following are factors that affect the generation of magma except for
crystal size
decompression melting occurs because of
decrease in pressure
as sediments travel further from their source their grain size ____ their angularity ___ and they become increasingly ____
decreases increases well sorted
what mineral is the hardest known substance in nature
diamond
an erosional surface between parallel layers of sedimentary rock
disconformity
in a normal fault, the hanging wall moves ___ relative to the foot wall
down
folding as a result of passive flow is a form of ____
ductile flow
cinder cones are built from
ejected lava fragments from fine ash to bombs
Which kind of eruptive activity is most likely to be highly explosive?
eruptions of big, continental margin, composite cones or stratovolcanoes
the composition of the core of the earth is thought to be ____
solid iron-nickel alloy
what physical property denotes the color of a powdered mineral
streak
what plate boundary is the san andreas fault?
strike-slip transform plate boundary zone
two most important variables that act together to determine the grade of a metamorphic rock
temperature and pressure
the sizes shapes and arrangements of mineral grains in an igneous rock are known as ____
texture
where along a slope would you expect to find the thickest soil deposits?
the bottom
extrusive igneous rocks are typically finer grained than intrusive igneous rocks. why
the extrusive magma cools quickly so the mineral grains do not have time to grow
what are volatiles
the gaseous components of magma
weathering is ...
the in-situ degradation of a geologic material through physical and/or chemical processes
physical weathering is ____
the mechanical breakdown of earth materials into smaller and smaller constituent parts
which of the following best describes an aphanitic texture
the rock is crystalline; mineral grains are too small to be visible without a magnifying lens or microscope
one factor limiting the heights of mountains is what?
the strength of rocks supporting the mountains
Which one of the following is not true for minerals?
they can be a liquid, solid, or gas
how do the electrons behave in a mineral with metallic bonding
they can move relatively easily from atom to atom inside the mineral
why are sedimentary rocks valuable to study? what info can we gain from them?
they contain a history of life on earth they are reservoirs of important natural resources they archive earth's climatic history
ocean sea mounts provide support for the theory of plate tectonics because they ____
they track the movement of plates over hot spots
in which climatic zone would you anticipate finding the most developed soils
tropical climate (warm with abundant rainfall)
