final Flashcards
_____ is the scientific study of fossils.
paleontology
Human activities can influence the ______ and ______ of geologic processes and events.
magnitude and frequency
Physical geology contains the subfields of
geomorphology, hydrology, and sedimentology.
_____ is the term used to describe the increase in the acidity of the oceans.
Ocean acidification
Which of the following resources is used to make cement?
limestone
The calendar of Earth’s history is called
geologic time scale
____ is the collection of information and data about distant objects or environments.
Remote sensing
which era are we currently in?
Cenozoic
____ is a technique where the decay rate of radioactive isotopes is measured and used to determine the age of geologic material
radiometric dating
A rock that is 180 million years old comes from the ______ period
Jurassic
What is the ultimate source for naturally occurring carbon-14?
cosmic ray collisions and neutron capture involving nitrogen
What is the effective maximum range for carbon-14 dating?
70,000 years
___ was a guiding doctrine used to explain the formation of Earth’s features as results of sudden, often worldwide disasters produced by unknowable cause that no longer operate
Catastrophism
what is an example of a numerical date?
a meteorite impacted the earth 65 million years ago.
what is the half-life of potassium-40?
1.3 billion years
a deposit of volcanic tuff contains the isotope potassium-40, which is slowly decaying into argon-40. how might the apparent age of the sample be affected if the volcanic tuff is heated and remains heated for a long period of time?
the sample will appear younger than it really is
in radioactive decay, an unstable ____ isotope will decay into a stable ____ isotope.
parent, daughter
the fossil record is biased toward
preserving organisms with hard parts
An interval of time between ice ages is referred to as a(n) ______ period.
interglacial
In ~11,000 years, the North Pole will be pointing at __________.
Vega
Which of the following refers to the variation in the Earth’s orbit around the Sun and its influence on past climate fluctuations?
eccentricity
The beginning of the Industrial Revolution is clearly recorded in ice cores as an
increase in pollution
The majority of Earth’s freshwater is located
ice sheets and glaciers (polar ice)
What is not part of the Milankovitch Cycle?
isostasy
When did the last ice age end?
~10,000 years ago
During the Mississippian period, Earth’s average global temperature was
~22°C.
What is the definition of a scientific theory?
a well-tested and widely accepted view that explains observable facts
Organized procedure that involves making measurements and observations
experiment
A system is
any organized entity that consists of interrelated and interacting components
_____ is a description of how scientists measure natural phenomena and rigorously test new ideas about how some part of the natural world works.
The scientific method
Factor in an experiment that can be manipulated by the experimenter
independent variable
Factor in an experiment that can change if other factors are changed
dependent variable
What is the relationship between the four subsystems of Earth?
The four subsystems overlap and interact with each other.
The mean residence time for water in permafrost is ______ than the mean residence time for water in lakes and streams.
longer
___ is the fundamental ingredient for life on Earth
water
The only substance on Earth that occurs naturally as a liquid, a solid, and a gas is
water
Interception of precipitation by vegetation allows
greater infiltration
Long narrow grooves gouged into the rock by glacial erosion are called
striations
Humans are considered to be part of which of Earth’s four subsystems?
biosphere
Liquid water is transformed into water vapor through
transpiration and evaporation
Glacial ice always moves in a
downward direction
The average temperature on the moon is _______ whereas the average temperature on Earth is __________. Though they are about the same distance from the sun, the __________ keeps Earth warm.
-18 °C; 15 °C; greenhouse effect
Rainwater will combine with which atmospheric gas in order to create carbonic acid?
carbon dioxide
Landforms created by water in streams and rivers are called
fluvial landforms
What was the first element to be formed after the “big bang”?
hydrogen
A region around a host star where a planet with sufficient atmospheric pressure can maintain liquid water on its surface is known as a
habitable zone
Earth is _____________ from the Sun.
~8 light minutes, ~93 million miles
A radio wave can have a wavelength the size of a
football field
Proxima Centauri is _____ from Earth.
~ 4.2 light years
The constant path that Earth travels in its orbit around the Sun describes a surface called the plane of the
ecliptic
A(n) ________ is defined as a cataclysmic, explosive death of a star
supernova
How many planets are in our Solar System?
8
The Sun is described as a
main sequence star
Earth revolves around the Sun in a _______ direction
counterclockwise
The shortest wavelength of visible light falls at about _____ nanometers and is ________.
375; violet
list the correct order of the terrestrial planets when moving away from the sun
Mercury, Venus, Earth, Mars
list the correct order of the gas giants when moving away from the sun
Jupiter, Saturn, Uranus, Neptune
The accumulation of particles and material into a massive object by gravitationally attracting more matter is a process known as
accretion
A light year is
the distance light travels in one year
The point in the Earth’s orbit where it is closest to the Sun is called
perihelion
The process of ________ is responsible for the energy generated by the Sun
nuclear fusion
What is a planetesimal?
Rocky material accreted through repeated collisions
The atomic number of uranium is
92
What is the name of the star in our solar system?
the Sun
Light travels _____ miles in one year
~6 trillion
What caused our solar nebula to contract and spin, eventually creating the planets
Gravitational interactions between particles
The instrument used to measure and record an earthquake is a
seismograph
______ attempts to explain the formation of the solar system.
The nebular theory
Regions where seismographs do not record P and/or S waves are called
seismic shadow zones
What is the depth of the deepest well on Earth?
12 km. Russia
put the waves in order from slowest to quickest
surface waves, S-waves, P-waves
An isotope of oxygen has 8 protons, 10 neutrons, and 8 electrons. What is the atomic mass of this isotope?
18
What is the charge of a single proton?
+1
Outside of the crust, the layer that scientists know the most about is the mantle. Other than via seismic waves, how else do geologists obtain information about the composition of the mantle?
volcanoes
What is not one of the three compositionally distinct layers of the Earth’s interior?
lower mantle
The interior of the Earth is divided into roughly spherical layers of differing
density
Na
Sodium
Ca
Calcium
Fe
Iron
K
Potassium
Si
Silicon
Mg
Magnesium
What is the age of the oldest radiometrically dated rocks yet discovered on the planet (located in Canada)?
4 billion years old
Since temperatures in Earth increase with depth, why is the inner core solid?
The pressures in the core are immense and keep it in a solid state despite the temperature.
Continents have a density of ________ and are made of ________ rock
2.7 g/cm3; granite
Ferromagnesian minerals contain
magnesium and iron
A ________ occurs when an iron-rich fluid in the core is electrically charged and flowing, which generates a magnetic field
geodynamo
The composition of the upper mantle is defined by ________
peridotite
What is the asthenosphere?
A comparatively weak layer in the upper mantle
The ________ layer is thought to be a highly variable layer with large variations in composition as well as temperature
D”
The Mohorovičić discontinuity or Moho was discovered based on
a sharp change in seismic velocities.
Which two minerals define a felsic composition?
Quartz and potassium feldspar
A fine-grained mafic rock is
basalt
Which ferromagnesian mineral is believed to constitute up to 50 percent of the mantle?
olivine
What three components make up most magmas?
liquid portion, solid portion, gaseous portion
What is necessary for a mineral to cement rock grains together?
The cement mineral must be dissolved in water.
Which minerals are the main constituents in most sedimentary rocks?
Quartz and clay minerals
A ________ describes the observation of successive changes in a laterally continuous sedimentary layer that are visible and are interpreted as a result of many depositional processes taking place over a large area.
facies
________ is a biochemical sedimentary rock that often forms in carbonate reefs.
Coquina
_____ describes the range in particle sizes in a detrital sedimentary rock
sorting
What is diagenesis?
The changes that convert sediments to sedimentary rocks after deposition
in situ
in place
What trace material produces red colors in some sandstones
iron oxide
Rocks formed by the solid-state transformation of minerals in a preexisting rock due to elevated temperature, pressure and/or hot fluids are called
metamorphic rocks
The ____________ is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can determine geologic ages of strata
law of fossil succession
Turbidity currents deposit sediment on the _____
continental rise
When rocks are _____, several adjacent layers were deposited without interruption
conformable
What is stratigraphic correlation?
Matching up rocks of similar age in different regions
Passive margins such as ________ are characterized by minimal tectonic activity, but abundant weathering and erosion processes.
the East Coast of the United States
______ is produced when a conglomerate is subjected to metamorphism that involves differential stress
a metaconglomerate
Hawaii is the result of a
hot spot
what physical feature represents the transition from the continent to the ocean basin
the continental slope
Bathymetry is
the study of the “beds” or “floors” of water bodies such as oceans, lakes, and rivers
Which scientist is credited with developing the law of superposition
Nicholas Steno
By putting events in order, scientists can use the order to determine
how long ago certain geologic events took place
Which type of plate boundary most commonly produces metamorphism
convergent
What evidence found in modern day tropical regions of southern Africa and South America most strongly supports the hypothesis that the continents were once joined?
glacial debris
Samples from the seafloor around the Mid-Atlantic Ridge and the East Pacific Rise show that both areas have been creating new oceanic lithosphere in the last five million years. Samples from the East Pacific Rise show the five-million-year-old seafloor is three times as wide as similarly aged material from the Mid-Atlantic Ridge. What does this say about the rate of seafloor spreading in the East Pacific?
The seafloor at the Mid-Atlantic Ridge is growing more slowly than the East Pacific Rise.
In which layer of the Earth does the convection necessary for plate motion occur?
mantle
________ can produce intricately folded rocks
Differential stress
When did Pangea begin to spilt apart?
~200 million years ago (mesozoic era, triassic-jurassic periods)
Most places that experience earthquakes are located near
tectonic plate boundaries
What best explains the global distribution of plant species, such as the Glossopteris, during the Mesozoic?
The landmasses were joined and the plant had a large geographic extent
The North American plate is predominantly
Continental lithosphere
7 major tectonic plates
North American plate
South America plate
Pacific plate
African plate
Antarctic plate
Eurasian plate
Indo-Australian plate
The Pacific plate is predominantly
Oceanic lithosphere
The Nazca plate is predominantly
Oceanic lithosphere
The Philippine plate is predominantly
Oceanic lithosphere
The African plate is predominantly
Continental lithosphere
The Eurasian plate is predominantly
Continental lithosphere
What direction was the Pacific plate moving between 65 and 43 million years ago?
North
What direction has the Pacific plate been moving for the last 40 million years?
Northwest
As the island of Hawaii continues to move away from the mantle plume, a new submarine volcano will be created. Off which coast would you expect the new submarine volcano to be forming?
Southeast coast
Steno’s Laws use what type of dating?
Relative
If an igneous rock is light in color, it’s composition is
felsic
An example of coarse-grained mafic rock is
gabbro
What type of environment will most likely have the presence of calcite cement?
semi-arid/arid climates
What creates small holes found in a vesicular texture?
volatiles
What category of igneous rock is Andesite?
Intermediate
Lava flows _______ the surface; Magma flows ______ the surface.
above; below
What is the age of the oldest radiometrically dated rocks we have so far discovered on Earth, located in Canada?
4 Billion Years
A disconformity is a type of unconformity where
the layers of rock are parallel
(Match the rock to its respective composition)
Granite
Felsic
The easiest way to distinguish a sedimentary rock from other types is by its
bedding
Active continental margins do not have a very pronounced
continental slope
Earthquakes caused by isostatic adjustments typically are a _____ magnitude than earthquakes at tectonic boundaries.
lesser
(Match the rock to its respective composition)
Andesite
Intermediate
(Match the rock to its respective composition)
Gabbro
Mafic
(Match the rock to its respective composition)
Peridotite
Ultramafic
Compaction and cementation _______ the porosity of a sedimentary rock
decrease
Relatively speaking, which is the finest grained clastic category listed?
Gravel
Silt
Clay
Sand
Clay
The _______ is an excellent demonstration for all types of unconformities
Grand Canyon
When strata is conformable, it is ________ without interruption.
deposited
The Greek word lithos means
rock
What is stratigraphic correlation?
Matching up rocks of similar age in different regions
Put the clastic grain sizes in order of most fine-grained to most coarse-grained
Clay, Silt, Sand, Gravel
Which igneous rock texture is associated with fluid-rich environments and has exceptionally large crystals?
Pegmatite
What is the term for the process by which sediment becomes rock?
Lithification
What is a characteristic of metamorphic rocks?
They are formed by the alteration of pre-existing rock deep within Earth (but still in the solid state)
What is the metamorphic rock for shale?
Slate
What is the primary difference between intrusive and extrusive igneous rocks?
their grain size
What is an example of a pyroxene?
augite
What is the primary mineral composition of a mafic rock?
Pyroxene and Plagioclase Feldspar
what type of unconformity occurs when sedimentary rocks are deposited on eroded or weathered igneous or metamorphic rocks?
Nonconformity
What type of unconformity is formed when sedimentary rock layers are deposited on eroded, tilted, or folded layers?
Angular Unconformity
What rocks is likely to have a pyroclastic texture?
Tuff
What is an example of a chemical sedimentary rock?
limestone
Current ripple marks are
asymmetrical
What is the primary type of organic material in
organic sedimentary rocks?
carbon
Mid-oceanic ridges are relatively ____ due to the processes that form new crust.
warm
During the last ice age, sea level was lower exposing more of the _____
continental shelf
What is the parent rock of gneiss?
granite
The major feature of the ocean floor that winds over 70,000 km around the planet is known as
mid-oceanic ridges
Which type of stream is able to transport silt and clay (i.e. smaller grain sizes)?
Meandering
Cratons are tectonically _______ areas of the continents
passive
Coarse-grained sediments such as gravel and coarse sand is characteristic of
glacial environments
_______ is the study of floors/beds of water bodies
Bathymetry
What type of boundary more commonly produces metamorphism?
convergence
If a stream is described as carrying coarse (i.e. larger) grain sizes such as gravel, it would be a
Braided Stream
What type of bedding is known for their sediments gradually changing from coarse at the bottom layer to fine at the top layer?
graded bedding
What feature represents the transition between ocean basins and continents?
continental slope
_______ margins are near plate boundaries
Active
The size of the continental shelf can increase due to deposition during
isostatic rebound
The part of the cratons that are covered in sedimentary rocks are known as
stable platforms
The Appalachian Mountains finished coming together during the
Paleozoic Era
The East Coast is an example of a _______ margin
passive
The principal source of atmospheric moisture is
the ocean
as a star moves away from earth, its light is ______ due to the Doppler effect
red-shifted
earth’s average surface temperature is
~14 °C
A glacier is a _____ that forms over hundreds or thousands of years
thick ice mass
_____ weathering is when physical forces break rock into smaller and smaller pieces
physical
_____ describes the formation of the universe
the Big Bang Theory
what describes the relationship between the wavelength and frequency of electromagnetic energy?
as wavelength increases, frequency decreases
what type of electromagnetic energy is not harmful to living things such as plant life and humans?
radio waves
what is not an agent of erosion?
heat
the greenhouse effect refers to the
process through which Earth’s lower atmosphere is warmed because longwave radiation from Earth is trapped by greenhouse gases
which layer of the atmosphere is the coldest of the four?
mesosphere
any type of rock may be
transformed into another type of rock
felsic magma has a ____ silica content
high
in an igneous rock with a phaneritic texture, the minerals grains are
visible to the unaided eye
rocks exposed at the surface slowly deteriorate by
weathering
many marine organisms such as coral, clams, oysters, and foraminifera produce the mineral substance ______, which will later become limestone.
calcite
which mineral group makes up most igneous rocks?
silicates
______ is molten rock that is below the Earth’s surface and retains most of its volcanic gases
magma
what best describes a pegmatitic texture?
large crystals that form in a fluid-rich environment late in crystallization
which mineral cements together grains in sandstone?
calcite
mineralogy
the chemistry, crystal structure, and physical properties of minerals
volcanology
volcanoes and volcanic events
how do you distinguish a sedimentary rock from other types?
its bedding
sedimentology
sedimentary rocks and the processes that form them
paleoclimatology
ancient climates throughout geologic time
hydrology
the distribution and movement of water both on and below the Earth’s surface
proxy data
data used to study a condition/situation where there is no direct evidence
2 examples of proxy data used in paleoclimatology
marine sediments, fossil pollen
3 causes of the current rise in mean sea level
loss of sheets and glaciers, thermal expansion, reduction of liquid water stored on land
what is high tide flooding (aka King tide flooding)?
exceptionally high tides that causes flooding
where in the moon’s orbit around the earth are king tides likely to form?
perigee (when the moon and earth are closest in orbit)
2 moon phases that contribute to the formation of King tides
new/full moon, perigee
during the Mississippian, global temp was closest to
22 °C
(abundant organic material, led to preservation, warm temps, fossil fuels we used today were deposited during this time)
what epoch are we in
holocene (the last ~10,000 years, modern region/climate)
what period are we in
quaternary (last 2.58 million years)
what eon are we in
Phanerozoic
orbital variations
eccentricity!!! the shape of earth’s orbit. 100,00 year cycle, climate change today happens way more rapidly than this.
milankovitch cycles describe
the long-term, collective effects of changes in the Earth’s position relative to the Sun and its role on climate over thousands of years.
it focuses on glacial and interglacial periods.
focuses on the quaternary period.
plane of the ecliptic is the same thing as the
orbital plane
tilt obliquity
the degree of axial tilt, 22.1° - 24.5°, the reason we have seasons, plane of the ecliptic, ~40,000 year cycle
Anthropocene
proposed epoch that emphasizes human impact (anthro=human), this isn’t on the geologic time scale
axial precession
wobble through its axis as earth rotates. 26,000 year cycle. direction of earth’s axis, where it points.
humans move _______ of rock and sediment every year
100+ gigatons
hypothesis
proposed explanation based on limited evidence, a starting point for further investigation, must be testable.
experiment
scientific procedure to make a discovery, test a hypothesis, or demonstrate a known fact.
scientific theory
a well-substantiated explanation of some aspect of the natural world, has withstood rigorous scrutiny (can be modified.. sometimes due to new technology)
scientific law
a description (often mathematical) of an observed phenomenon, doesn’t explain why the phenomenon exists or what causes it
