Geology Ecore Midterm
Measure the distance using the bar scale between the pole 1400 and 1700 (locations C and F). How far did the pole move?
1000 Km
What is the longitude for the northwest corner of the map?
110° 52' 30′′ W
What is the elevation of the base of the monument in meters?
12 meters
According to the geothermal gradient, rocks at 500 degrees Celsius will be buried how deep? At 500 degrees Celsius, rocks will be buried to about _______ km depth.
12.5
According to the geothermal gradient, rocks buried 75 km beneath the surface would normally be at what temperature? At 75 km depth, rocks will be heated to about _______ degrees Celsius
1250
the archeologist determines that there is 16.7% of the parent isotope remaining in the cloth sample. How old is the burial site?
14,798 yrs
Which of the following places represent a Wadati-Benioff zone?
15°S, 180°
Approximately how far did the pole move per day?
16 M
The elevation of point "C" is:
160 feet
Based on the choice you made for question 15, what is the density of the rocks that make up continental crust? Please give your answer in grams/milliliter.
174.6/70= 2.5 g/ml
Based on the choice you made for question 17, what is the density of the rocks that make up oceanic crust? Please give your answer in grams/milliliter.
179.7 g/ 60 ml= 3.0 g/ ml
Of the following dated flood events, which one would you expect to happen more often?
2/24/2013
What is the contour interval for the map below
20 feet
Measure the distance, using bar scale, between the pole in 1400 and 1500 (locations C and D). How far did the pole move?
5 Km
How far (in Km) did the pole move in one year during this time period?
6 km
How far did the pole move in meters in one year during this time period?
6000 M
Given that this portion of the Australian plate moves at a speed of 2.2 inches per year, how old are the snake fossils?
62 million years old
What is the longitude for the Washington Monument
77 02 'W
based on your graph approximately how much of the parent isotope would be remaining after 3.5 half lives
8%
Find Sloans Crossing. It is south of Mammoth Cave. What is the benchmark elevation at Sloans Crossing?
834'
Observe your best fit line. What approximate discharge would be associated with a 50 year recurrence interval?
8500 CFS
What is the elevation of the unlabeled index contour crossing Roaring Creek in the northwest corner of the map?
8800 feet
The rock that most closely resembles the composition of continental crust based on the description in the previous section is:
A (174.6 )
examine the unconformity shown in figure 1.10. what type of unconformity is this?
A- Angular unconformity
which Geologic Law did you use to come to the conclusion you made in the previous question (figure 1.8)?
A- the Law of superposition
which of the above geologic events is the second in the sequence
A-Tilting
If the river on this map is 1.93 miles long, what is the gradient for this river?
About 72 feet/mile
Inspect the P wave velocities. Where do the P waves abruptly change?
All of the above
Now look farther south of Sloans Crossing at Hwy. 31W. Look closely at the topography south of highway, and it changes abruptly. What feature(s) can you observe south of Hwy. 31?
All of the above
Observe the S wave velocities. Where do the S wave velocities abruptly change?
All of the above
which of the above geologic events is the fifth in the sequence
H-Fault
The zone from 5100-6400 represents the Earth's ?
Inner Core
which organism was the least useful in coming to this conclusion (worst index)
Isoletus
Brazil Lat and Long
Lat is N S Long is E W
Compare the contour intervals from the Royal Gorge, Colorado map (map 5.1) to the Omaha N, Nebraska-Iowa map. Would you expect the gradient of the Missouri River in Nebraska to be greater or less than the gradient that you calculated for the Grape River in Colorado?
Less than the grape river gradient
Do Pole movements seem to be steady every 100 years or variable?
Movements are variable
Is the school likely to be at risk of contamination from this same leak?
No
Locate the Louisville and Nashville Railroad line just south of Hwy. 31. Would this be an easy location to maintain a railroad?
No
Refer to the figure below. If the counter interval is 10 feet, which hill (a,b,c) when viewed from the base is 40 feet tall?
None of these
Consider the ages and positions of the islands listed above along with what you know about plate tectonics and hotspots. In what general direction is the Pacific Plate moving?
Northwest
Locate Little Sinking Creek in the southern portion of the map, north of Hwy. 68 and south of the Edmonson County Line. In which direction does it flow?
Northwest
which organism was the most useful in coming to this conclusion (best fossil index)
Ambonychia (I)
There are fossils such as Glossopteris and Lystrosaurus that are found in rocks in South America and Africa that indicate they were part of Pangaea approximately 200 million years ago. These same fossils can be found in Australia, which indicates it, along with Antarctica, was also part of Pangaea at that time. Based on your answer to question 6 which of the following statements about the break-up of Pangaea is TRUE?
Australia and Antarctica separated after the break-up of Pangaea.
In Figure 1.8, which of the following rock layers is oldest?
B
In Figure 1.9, which of the following geologic structures is youngest?
B- Unconformity
Refer to the figure below and assume contour interval of 10 feet. If you were standing in the middle on the intermost contour line hill "c", your elevation would be
Between 40 and 50 feet
In which zone do the P wave velocities appear to be steadily increasing?
Both A and B (20-2900 Km and 2900-5100 Km)
What is the physical state of a dry mantle rock at point X?
Completely solid
What type of tectonic plates are present?
Continent- Continent
What type of process is going on at this location?
Continental rifting
What type of plate tectonic boundary is present?
Convergent
The Wadati-Benioff zone is associated with which type of plate boundary?
Convergent (Continent-Ocean or Ocean-Ocean)
The Zone from 0-20 km represents the earths?
Crust
In this stream, erosion is occurring on the ______________ because _______________, while deposition is occurring on
Cut banks, the fast velocity flows to this point; point bars the slowest velocity water flows to this point
The rock that most closely resembles the composition of oceanic crust based on the description in the previous section is:
D (179.7 )
Notice the general shape of this feature. It is thought to have formed by the runoff of either precipitation or groundwater. What type of drainage does this appear to be?
Dendritic
This plate boundary isn't as simple as the previous examples, meaning another nearby plate boundary directly influences it. Zoom out and examine the area, what other type of boundary is nearby?
Divergent
Observe the stream on the Omaha N, Nebraska-Iowa quadrangle. In which stage of the cycle of stream erosion is this area?
Old age
Is Lake Creek flowing into or out of Phelps Lake?
Out of the lake
What is the term for the geologic feature called Carter Lake?
Oxbow lake
Observe the velocities of waves on the graph. Which one travels faster?
P waves
Examine the figure below. A topographic profile along the A - A' line is shown correctly in:
Profile 2
These features you are seeing are linear valleys. Assume that water flowed through these valleys at some time. What type of drainage pattern would this area represent?
Rectangular
Go back to the location in Google Earth that you examined for question 36 (46 55 25.66 N 152 01 25.17 E). Which of the three proposed plate tectonic mechanisms would NOT occur at this location?
Ridge push
At 2900 Km the S wave velocity falls to 0. Why?
S waves cant travel through liquids and this depth is where the liquid outer core exists
How fast was the Pacific plate moving during the last 1.1 million years between the formation of the Big Island and Maui in cm/year? To calculate this divide the distance (in centimeters) between the two islands by the difference in their ages.
Speed = 13.32 cm/ year
What does this type of drainage pattern indicate about the area?
Stream channels radiate outwards like wheel spokes from a high point
Is it possible that a flood with a similar discharge to that of the event from 9/23/2009 could happen again in the next 20 years?
YES
Is the church likely to be at risk of contamination from this same leak?
Yes
Was Carter Lake cut off before or after the state boundary between Nebraska and Iowa was drawn?
after
How were these lakes formed?
as sinkholes, underlying soluble rock was dissolved and area collapsed
Calculate the stream gradient of Grape Creek in ft/mile. Use the index contour just above the "m" in Temple Canyon for your initial spot. Measure the gradient to the index contour past the word Creek (the last contour before it reaches Arkansas River). The distance between these areas is ~1.6 miles (measured along the curving distance of the non-magnified stream). What is the gradient?
c. 125'/mile
Examine the headings of the measurements that you took for the previous two questions. The headings indicate the direction the Pacific Plate is moving over the hot spot. How does the direction of motion of the Pacific Plate during the last 1.1 million years differ from direction of movement between 4.7 and 7.2 million years ago? The direction of plate movement in the last 1.1 million years
c. has become more northerly
an archeologist finds some cloth at a burial site and wants to determine the age of the remains. which isotopic system should they use
carbon 14
Between the index counters on this map, the river gradient is
close to 73 feet a mile
What type of stream drainage pattern is present on this map? This may be easier to determine by examining the tributaries to the main stream.
dendritic
Are streams in this area downcutting or laterally eroding?
downcutting
The river in this area has a rather particular pattern, what geologic process caused this?
during a flood the river breached the natural levee flowing into the floodplain
Are the rocks likely tilted and folded or horizontal?
horizontal
Keeping the abrupt topography change in mind, which of the following is true?
in the southern portion of the map, the area is underlain by limestone
Follow the creek along its path. Where does it wind up?
it disappears underground
What type of bedrock is present in this area?
limestone
The river in this figure is flowing
out of the lake
A person standing at point "F" would only be visible to a person standing at:
point E
The steepest slope is found between:
points C and E
Locate the state boundary between Nebraska and Iowa along the Missouri River. Why does the boundary depart from the river channel?
the boundary follows the course of the river at the time it was drawn, the river has since moved
Based on the drainage pattern type, does the bedrock underlying this area consist of rocks uniformly resistant to erosion or rocks alternating between resistant and non-resistant layers?
uniformly resistant bedrock
In which stage of the cycle of stream erosion is this area?
youthful
What type of plate tectonic boundary is present?
. Convergent
If you decided to walk to from the monument to the white house how far would u have to walk in miles?
0.56 miles
The Grand Canyon is an extraordinarily steep area. If you go from the river at (36 05 35.38 N 113 14 43.70 W) Straight up north the canyon rim pressing down on the middle mouse wheel and moving the mouse forward and backward or by clicking on the arrows above and below the eye in the upper right hand portion of the window. What is the gradient of the GC
0.673
How far is that distance (0.56 miles) in Kms?
0.9 km
Examine the path of the river that feeds into and flows out of Quail Lake. What direction is the North American plate moving in comparison to the Pacific Plate at this location?
East
If you were standing at the washington monument what direction would you need to walk to get to the U.S. capitol building?
East
Based on the assemblage of organisms (A-I) in this sample, what is the age of this rock?
Fairmount
What features would you expect to occur at this type of boundary?
Volcanoes and a valley
What features would you expect to occur at this type of boundary?
Volcanos, earthquakes and a trench
In what direction was the main river flowing?
WEST
How fast was the Pacific plate moving from 7.2 million years ago to 4.7 million years ago between the formation of Kauai and Nihoa in cm/year? To calculate this divide the distance (in centimeters) between the two islands by the difference in their ages
Speed = 10.89 cm/yr
Measure in centimeters the distance (Map Length) between the two points you recorded in the previous question. Given that this portion of Pangaea broke apart 200,000,000 years ago, calculate how fast South America and Africa are separating in cm/year? (Hint: Speed= Distance/Time)
Speed = 2.88 cm/year
What happens when the lithosphere at point X is heated to 1500 °C?
Starts to melt
What would happen to the mantle rock at point X if water is added to it?
Starts to melt
Which gas station is the most likely source of the gasoline leak?
Station A
Zoom out and examine the surrounding area, what geological hazards are likely in the area?
flooding of urban areas
During the flood event of 9/23/2009, the discharge measured at this gaging station was 21,200 cfs. Note where this would plot on your graph. Would the recurrence interval for this flood plot at:
longer than 1,000 years
What type of drainage pattern is present in this area?
radial
think about the drainage pattern you selected in the previous answer - what does this tell you about the underlying rocks?
the rocks are probably fractured
how much of the parent isotope would be remaining after 7 half lives have passed
0.78%
What is the straight line distance between the 8996 b and the 7202 b benchmarks located north and northwest of Phelps Lake? (The benchmarks have an "x" to locate the spot where the elevation was surveyed).
1.2 miles
based on your graph above approximately how many half lives have passed when only 35% of the parent isotope is remaining
1.5
the geologist determines there is 78.3% of the parent remaining in the sample that they examine. how old is the sequence of rocks
1.588 billion yrs
The elevation of point "A" is:
120 feet
The elevation of point "B" is:
120 feet
On which date did a flood event have a recurrence interval of 0.5?
2/27/2013
Examine the map below to answer the question. Contour values are in feet. What is the approximate map relief?
2080 feet
if a radiometric element has a half life of 425 yrs, how old would a rock be that only had 3.125% of the parent isotope remaining
2125 years
How far have the snake fossils moved apart since they were originally deposited?
2150 miles
The elevation of point "F" is:
240 feet
At what depth will the dry mantle rock at point X begin to melt if it is uplifted closer to Earth's surface and its temperature remains the same?
25 km
How far apart are North America and Mainland Asia in cm? (measure the distance across the Pacific at 40 degrees north latitude- basically measure between Northern California and North Korea)? Take that distance and divide it by the speed you calculated in question 3 to estimate when the next supercontinent will form. Show your work!
292.5 million years
Flood stage, or bankfull stage, on Sweetwater Creek occurs at a discharge of ~4,500 cfs. According to your best fit line, what is the recurrence interval of such a discharge?
3 years
How big is the base (area) of the washington monument in sq feet?
3100 Feet
The relief of this map is:
360 feet
Search for the "Washington Monument" and zoom into 3000 feet eye altitude. What is the latitude for this monument?
38 53 'N (LAT is N/S Long is E/W)
locate the base of the monument. What is the elevation of the base in feet
40 feet
What is the latitude for the southeast corner of the map?
43° 37' 30′′ N
The direction system is useful but imprecise. What bearing would you need to walk to go to the Smithsonian from the monument?
75
which Geologic Law did you use to come to the conclusion you made in the previous question?
B- Law of cross cutting
which of the above geologic events is the seventh in the sequence?
C. Submergence and deposition of sedimentary layers 10-13
Given that San Francisco is located on the North American Plate and Los Angles is located on the Pacific Plate, are these two cities getting closer together or farther apart over time?
Closer
Using the speed you calculated in the previous question (and ignoring possible changes in sea level), when will the Big Island of Hawaii sink below the surface of the ocean? Divide the current maximum elevation of the Big Island by the rate you calculated in the previous question.
It will take approx. 8,194,375 years to sink
What factors control the course of this river?
Low gradient and abundant sediment supply
The zone from 20-2900 Km represents the earth?
Mantle
How would one describe this river?
Meandering
What type of tectonic plates are present?
Ocean- Continent
What type of tectonic plates are present? Hint- make sure to re-read the section on plate boundaries before answering!
Ocean- Ocean
What type of tectonic plates are present? Make sure to zoom out to get a good view of the relevant features
Ocean- Ocean
Remember, because of isostasy the denser plate will be lower than the less dense plate. If oceanic and continental crust collided, based on their densities the __________ crust would sink below the ________crust.
Oceanic, Continental
The zone from 2900-5100 represents the Earth's ?
Outer Core
The speed the islands are sinking can be estimated by measuring the difference in elevation between two islands and dividing by the difference in their ages (this method assumes the islands were a similar size when they were active). Calculate how fast the Hawaiian Islands are sinking, by using the ages and elevations of Maui and Nihoa.
Rate of sinking = 0.0016 ft/year
Examine unconformities 1 and 2 indicated in Figure 1.9. Which of the following statements about them is true?
The older unconformity is a Nonconformity, while the younger is a Disconformity.
Which of the following lakes has a shoreline that is most likely at an elevation between 10,240 and 10,320 feet above sea level?
Timberline Lake
What type of plate tectonic boundary is at this exact location?
Transform
a geologist is trying to date a sequence of sedimentary rocks with abundant fossils and sandstones. within the sequence is a distinctive clay layer that under closer inspection is fine grained volcanic ash. which of the following is the best way to obtain an absolute date for the sequence of rocks
uranium date the zircons in the ash
