120 terms

Geology Exam 4

With respect to the dangers of mass wasting which of the following conditions would be the best in terms of locating a house or structure?
gentle slope, light and steady rain and heavy vegetation
In order for caves and cave deposits to form which of the following conditions must be met?
dissolution must take place below groundwater table followed by deposition when the cave is above the groundwater table
Very slowly moving mass wastage is known as
The deposits of stream sediments that are associated with periodic flooding are known as?
Of Earth's water, approximately what percent is not ocean or glacial?
What is the origin of geothermal water in places such as Iceland?
Its recycled precipitation
Typical rates of flow for groundwater are
The geologic time scale is constructed from
the principles of radioactive decay and a sequence of geologic and biologic events
A drainage basin is
a region bounded by divides, containing all the tribuataries of a main stream and carrying all the runoff from the entire region
What is karst?
a type of landscape
Construction of a dam in the path of a river will have what effect on base level?
temporarily raise it
Which of the following mass wasting processes is called creep?
Which of the following states or places is most prone to sinkhole formation?
An imaginary line below which rivers cannot erode is called?
base level
Why is little groundwater found at depths greater than 750 meters?
there are few open pores below that depth
Which of the following situations will lead to a decrease in erosion by a stream?
an increase in channel width
Debris flows differ from mudflows in that
debris flows contain material of larger grain size
Which of the following geologic ERA or EON is the oldest?
The recycling of water on Earth is described in?
the hydrologic cycle
Which of the following statements about the length of the Precambrian EON is correct?
It covers the first 4 billion years in Earth's history
Which of the following is an example of mass wasting?
Which of the following has not been used for dating in geology?
Approximately what portion of Earth's water occurs in streams, lakes and groundwater?
1 %
What kind of sedimentary deposit forms where a stream overflows in the lowlands?
a flood plain
Stalagtites from as a result of
precipitation of calcium carbonate from water in cave air
When groundwater reaches the water table, most of it flows
along downward curving paths
Which of the following questions about the water table is wrong?
It is always at the same depth in a given place
The type of mass wasting responsible for the greatest number of amount of property damage is
Which of the following is the most porous?
Radiocarbon dating of dead organisms is possible because
life forms stop accumulating carbon 14 when they die
Which of the following statements concerning radiometric dating is wrong?
Radioactive isotopes decay faster on Earth's surface than they do at Earth's core
The boundary between the zone of aeration (or zone of undersaturation) and the zone of saturation is known as the?
water table
Scientists have concluded that the Earth is 4.5 billion years old. Which dating method was used to obtain this age?
uranium-lead dating (half-life: 4.5 billion years)
Avalanches are known to obtain very high speeds due to the presence of trapped air. What role does this air play?
It decreases friction between grains
Porosity is
the percentage of the rock of sediment that is open space
The removal of water from the zone of saturation is known as
Groundwater returns to the rest of the hydrologic cycle mainly through
stream, lakes and the ocean
Most block glides occur in the areas where
the strata and the slope dip in the same direction
A sample currently contains 20 parent atoms and 60 daughter atoms. Given that the half-life is 2,000 years how old is the sample?
Which of the following would raise sea level?
global warming
Which of the following drainage patterns results from a river on a flat region consisting of hard bedrock with rectangular joints and cracks?
In meandering streams, water velocity tends to be the greatest
along the outer bank of a meander loop
We know little about Earth's history past the
Which of the following materials is most likely to be transported as suspended load?
clay or silt
What are the dimensions of stream discharge?
Suspended load includes all material
temporarily or permanently suspended in the flow
What type of drainage network would you expect to find on a volcano?
radial drainage
Which of the following statements about geysers is correct?
About half of the existing groundwater is found at depths
less than .75 km
Layers that transmit groundwater are called
In arid regions the groundwater table is
In which of the following situations of horizontal layering would you have a confined aquifer?
For a given river, which of the following floods would least likely to occur every year?
a 100-year flood
States in which extensive karst topography exits include
Texas, New Mexico, California, and Arizona
The fundamental cause (trigger) of mass wasting is
the gravity overcoming the slope's resistance
In the map of a stream above, the arrow is pointing to an
oxbow lake
Which of the following terms described a curved, coarse-grained deposit that forms on the inside curve of a stream?
point bar
Which of the following would be the worst in terms of mass wasting - worst for locating a structure such as a house?
steep slope, thick debris cover, and sparse vegetation
Mass movements would least likely occur in which of the following settings?
grow up from the floor of a cave
What powers the hydrologic cycle?
solar energy
What is an unconformity?
a gap in the geologic record
An undeformed sedimentary layer is ___ than the layer above and ___ than the layer below.
older, younger
Groundwater discharges naturally
wherever the groundwater table intersects the ground surface
The lowering of the water table near the well is called
cone of depression
The illustration above depicts a cross section through a pile of quartz sand. The angle depicted in the diagram is called the
Terraces form due to changes in
What kind of sedimentary deposit forms where a stream enters a standing body of water?
a delta
What is the regional aquifer called?
the Ogallala
The topographic rise between two streams is called a
drainage divide
Radiometric dating is least useful for dating _____ rocks.
In what type of rock do most limestone caves form?
The largest freshwater reservoir in the hydrologic cycle is
The property by which a paper clip can float the surface of a liquid is called
surface tension
Telephone poles that lean slightly downhill are a likely result of which of the following processes?
A rock currently contains 30 parent atoms and 90 daughter atoms. Given that the half life is 1,000 years (and the sample contained no daughters initially) estimate the age of the rock
The angle of repose does not depend on which of the following?
particle composition
Where do deltas form?
at river mouths
The Cambrian was preceded by the
Repeated flooding by a river creates a ____ along the banks of the river.
Which of the following types of mass movements could a person not outrun?
debris avalanche
Radiometric dating is possible if a rock contains a measurable amount of
both daughter and parent atoms
Which of the following would be the most fertile area for crops?
Einstein was one of many great minds to ponder why streams meander. He concluded a thought experiment whereby he used the concept of helical flow to explain the origin meanders. In class we refer this experiment as?
the teacup experiment
A radioactive has decayed to the point that 1/8 of the original content is left. How many half-lives have passed?
Which kind of drainage pattern develops around a steepsided cone-shaped mountain?
How will a stream respond if its velocity increases?
it will erode more
The half life of a radioactive isotope is
the time it takes for half of the radioactive atoms to decay
What type of drainage pattern is depicted in the map above?
The greatest casualties in a single flood occurred in
What kind of rock type was initially used to construct the geologic time scale?
fossil bearing sedimentary rock
Carbon-14 has a half life of approximately ______ years and is there for suitable to dating objects younger than approximately ______ years?
5 thousand and 50 thousand
Which country had the deadliest earthquake in recorded history?
Water vapor returns to the atmosphere from land by
Most major landslides
have natural causes
Stripping soil of vegetation by burning or deforestation will ______ the likelihood of mass movements
Avalanches are known to obtain unexpectedly high speeds due to the presence of?
reduction of friction due to trapped air
Energy waves that are released during an earthquake are called
seismic waves
Which of the following ERA or EON is the youngest (most recent)
Which of the following rivers has the greatest discharge?
the Amazon River in South America
If a dam is built, sediment will _______ on the upstream side of the dam and sediment will _______ on the downstream side of the dam.
accumulate, erode
A radioactive isotope decays down by 2 half lives. How many daughter atoms will have formed assuming that you had none to start with and started with 1000 parents?
Which of the following forces is the dominant cause of mass movement?
Sample contains 70 parent atoms and 30 daughter atoms. Assuming that sample contained no daughter atoms initially how many parents did it contain originally?
For a given river, which of the following floods would be most likely to occur every year?
a 5-year flood
Mass wasting is classified according to
type of material, rate and type of movement
Sedimentary rocks cannot typically be dated by radiometric methods. This is so because?
newly formed or true sedimentary minerals are difficult to date
As a river flows towards the ocean it narrows but stays the same depth. Which of the following is true about the behavior of the stream as the channel narrows? Assume constant gradient.
velocity increases
What is the role of water in mass wasting?
it adds weight and lowers friction
The ultimate base level for a stream is
sea level
Which of the following dating methods is not based on annual layering
The volume of water flowing past a given point given time is called the
Point B is called the earthquake
Large, cone shaped deposits of a sediment at a mountain front are called
alluvial fans
Which of the following slopes is least stable?
a slope where the sedimentary layers dip parallel to the slope
Braided streams develop where/when
bed load is very abundant
Curves and bends in a stream channel are called
Fission tracks is a dating method that is based on
tracks or scars left in minerals by the breakdown of radioactive elements
Which of the following best explains why there are no large deltas on the east coast of North America?
because the waves and tides in the atlantic ocean are too strong
On November 8 this year a large asteroid passed within 2,000 miles of Earth. The size of the asteroid was that of
an aircraft carrier