Upload
others
View
6
Download
0
Embed Size (px)
Citation preview
UNIVERSITY OF TORONTO DEPARTMENT OF CIVIL AND MINERAL ENGINEERING
CME 185 HiS - EARTH SYSTEMS SCIENCE FINAL EXAMINATION
DATE: 23 April, 2018 START TIME: 6:30 P.M.
DURATION: 2 AND % HRS
INSTRUCTORS: CHRIS ROGERS & SEMECHAH LUI
I
AIDS ALLOWED: Pencil, pen, eraser, ruler, protractor, pencil compass, non-programmable calculator.
INSTRUCTIONS: Write your name and ID, last name followed by first name, at the top of this cover sheet, in the space provided. All answers must be written on this exam paper. For Part I (True/False section), use the letter I for True and F for False. For Part II (Multiple choice), clearly indicate the letter that corresponds to the best answer for each question in the space provided. The last page is for sketching purpose. You may detach it for use during the exam. This page will be collected in the end, but anything written on this page will NOT be graded. Each question is worth one mark unless otherwise noted.
3. /11
4. /5
5. /5
6. /4
7. /6
8. /6
9. /9
- 10. /4
11. /5
12. /4
13. /8
14. /8
16. /13
17. /12
Total /100
I of 19
This page is intentionally blank.
2 of 19
4
Photo Page: Images A to E for Q.7 - 15 in PART III
PART I: True/False (11 marks, 1 mark each) Indicate whether the sentence or statement is true or false.
# Question True I False
Quartz and mica are some of the most resistant products of chemical weathering
2 Talus or scree slopes are made up of material formed by physical weathering
3 Clays are formed by hydrolysis of feldspars
4 On the Richter Scale, the magnitude is based on wave amplitude and does not consider duration of shaking.
Enforcement of good building codes is one of the best ways of preventing loss of lives due to earthquakes
6 Strike is the direction of a line, measured by a compass, formed by the intersection of a horizontal plane with an inclined structural plane such as a bedding or fault plane.
7 Land subsidence due to excessive extraction of ground water is usually reversible
8 You can identify permafrost areas because there is no vegetation on the surface.
9 An unconformity is a substantial break or gap in the geologic record where a younger rock unit overlies (on top of) a much older rock unit.
10 An aquiclude is of high permeability compared to an aquifer.
11 The land that the University of Toronto is on was covered by a lake about 12,500 years ago (after the retreat of the glaciers)
3 of 19
PART II: Multiple Choice (14 marks, 1 mark each) Identify the letter of the choice that best completes the statement, is the best answer, or answers the question.
1. Alkali-silica reactions in concrete are caused by alteration and dissolution of the following materials or rock types:
Limestone dolomitic limestone quartz poorly crystallized silica b and d
Qi:
2. The study of geology by engineers is necessary because: Engineers must understand the physical world in which they work To understand and communicate with others who are employed in scientific disciplines Natural sciences are the foundation upon which much of engineering design is built It helps us understand and mitigate the potential threats of geologic hazards such as earthquakes and volcanoes All of the above
Q2:
3. Which of the following is not an agent or process in chemical weathering of rocks and minerals?
Frost action Oxidation Hydrolysis Acid dissolution Algae and lichens
Q3:
4. Which of the following is not a rock or mineral formed by evaporation? Borax Chert Gypsum Halite
Q4:
5. What material underlies some parts of the sand beaches of Normandy and impacted choices for the D-day landings in 1944?
Silt Peat Quick sand Laterite Chalk
Q5:
4 of 19
6. Which of the following landforms are NOT formed in glacial terrain? Arêtes Cirques or Cwms Alluvial fans Horns none of the above.
7. To prevent listric faulting you can? Use lightweight fill such as Styrofoam blocks Remove weight at the top of the rotating mass Install materials at the toe of the fault Installation and grouting of rock anchors A,B and C
8. Glaciers advance under which of the following set of conditions? Snow accumulation is greater than melting Snow accumulation is less than melting climate warming Snow accumulation equals melting but there is also climate cooling none of the above
9. Sea levels are rising due to: Climate warming Ice caps melting Warming of ocean water A and B A,B,C
Q9:
10. Many shallow drilled water wells in Bangladesh and Western Bengal are causing a serious health hazard because of the presence of... in the water?
Bacteria Mercury Arsenic Hydrogen sulphide gas Asbestos
Q1O:_
5 of 19
11. The weight of glaciers on the land surface of Carada resulted in depression of the land surface.
Sometimes below sea level. The land has been slowly rising since the glaciers melted The slow rebound is called isostatic rebound The rebound is uneven and more rebound occurs where the most ice was located All of the above.
Qil:
12. The Vaiont (or Vajont) dam disaster in Italy in 1963 that resulted in over 2000 deaths was caused by:
The presence of an unstable rock slope that slid into the reservoir and created a wave that overtopped the dam. The dam being placed on high porosity rocks that resulted in structural failure due to uplift. The presence of a permeable fault zone at the base of the dam. The presence of weak rocks at the sides and foundation of the dam. Poor structural design.
Q12:
13. Which of the following glacial deposits are excellent sources of sand and gravel for use in construction?
Ground moraine. Glacial till End moraines. Eskers. All of the above.
Q13: -
14. Metamorphic rocks may form from: Igneous rocks. Sedimentary rocks. Other metamorphic rocks. A and B. A,B and C
Q14:
6 of 19
PART III: Short-answer questions (50 marks) Point form answers only; Marks will be removedfor bad spelling.
1. Draw some folded sedimentary rocks (show at least four layers - shale, limestone, sandstone and siltstone) in cross section. Label the anticline and the syncline. (3 marks, neatness counts)
2. Draw a cross section of a reverse fault in horizontally bedded sedimentary rocks (show at least 4 layers - see Q 1), show the direction of movement of the fault blocks relative to each other with arrows and label the foot and hanging wall blocks. (3 marks, neatness counts)
7 of 19
100
This map below shows the contours (in meters) of ground water table above sea level. Draw lines showing the direction of groundwater flow from points a, b and c (must be neat). (3 marks)
10
20
30
40
50
60
How deep is the groundwater table likely to be at point X? (1 mark)
Use Hjulstrom's diagram shown below for Q.5 and 6: 1000--- --
Erosion
Gravel
Transportation Sand
11tClay 4
Deposition
1/
A-
2.0 100
Particle size (diameter in mm)
Given that the velocity of stream water is 20 cmisec, what type of activity will occur to silt size particles? (1 mark)
Why is a higher velocity required to erode clay compared to sand? (1 mark)
0.1
256-
8 of 19
To answer Q.7 to 15, refer to the colour photographs on a separate page. (1 mark each)
Image A
This is an image of the Mississippi river taken from 26,000 ft. The feature indicated by the red arrow is a:
The feature near the yellow arrow is a:
Where will the river current be at a maximum (near the red or the yellow arrow)?
Image B
What kind of rock slope failure is shown in the photograph?
What would be the most appropriate ways to stabilize the face and prevent rock hitting the road below?
Image C
This is an image of railroad track disturbed in an earthquake in New Zealand. What kind of earthquake wave caused this?
Image
What kind of weathering is occurring in this igneous rock (basalt)?
Image
In the air photo below from New Zealand, what kind of river is shown?
What materials would you normally expect to find in this river?
9 of 19
The map below shows a portion of southern Ontario (Trenton Map sheet). The contour interval is 10 meters and North is at the upper edge of the map. Answer Q.16 to 19 using this map. (1 mark each)
)9\\ a
What are the hill features indicated by arrows from X?
What kind of glacial material would you expect to find in the features in Q.16?
18. What kind of river (marked as "creek") is shown?
What was the probable ice flow direction in this map area as indicated by the hills indicated by X?
10 of 19
This is a map of a previously glaciated area in the Canadian Rocky Mountains. The contour interval is 100 feet and North is at the top of the map. Answer Q.20 to 24 based on this map. (1 mark each)
What is the feature at 1, between the two mountain peaks, called?
The mountain (or type of mountain) shown at 2 is called a
The feature within the circle contains a small lake and is called a
The maximum height of the hill at point E is about
What direction is the stream shown at 3 flowing?
11 of IQ
25. The picture is an image of the shore line of Lake Ontario near the Bluffs in east Toronto. North is at the top of the image which shows about 500m of shoreline with groins going into the lake. What is the direction of long shore drift of sand and sediment? (1 mark)
The Aberfan coal mine waste disaster in Wales in 1966 that killed 110 school children was caused by? (1 mark)
In highway construction what are interceptor ditches and multipoint well point systems used for or what do they do? (1 mark)
The oceans are becoming more acid due to dissolved gas and this is harming shell forming creatures. What gas is mainly responsible for this? (1 mark)
12 01 19
In Italy, the earthquake in the town of L'Aquila in April 2009 was predicted by a seismologist Gioachino Giuliani. Changes in amount of what radioactive gas did he base his prediction on? (1 mark)
Why did the amount of gas increase shortly before the earthquake? (1 mark)
Explain why it is better to build your house on bedrock rather than sand in an earthquake area. (2 marks)
Identify the following types of seismic waves. (4 marks)
Direction of wave propagation
Undisturbed medium
/rty H :
J1:[ -1LTI r
i::Ii _1 L
Compress Ions
TT
--".--------_..---.-_-._..---'V.--- .-. -
Dilations
wave
&
wave
wave
wave
13 of' 19
An earthquake has occurred in the United States, and seismic signals have been recorded at three stations in the States of Texas, California and Missouri. Answer Q.33 to 35 using the travel-time graph below and the map on the next page.
33. On the travel-time graph, identify the P- and S-wave graphs. (1 mark)
34. The time separation between P- and S-wave arrivals at the three stations (triangles shown on the map) are as follow. Find the distances between the epicenter and the stations. (3 marks)
Station location P- and S-wave
arrival time separation Distance from epicenter
(km)
Houston, Texas 2 minutes 30 seconds
Los Angeles, California 4 minutes 30 seconds
St. Louis, Missouri 1 minute
35. Use the map and its map scale on the next page to find the approximate epicenter location of the earthquake. Show your steps. (4 marks)
_____ (I) TRAVEL-TIME GRAPH wave
14
13
12
10 C
wave
/
1 2 3 4 5 DISTANCE FROM EPICENTER (10 km)
L4 of' 19
T--
: -
0 km 500 1000 1500 2000 2500 3000 3500 4000 4500 1 1 1 1 1 1 I 1 1
PART IV: Geological Maps (25 marks)
MAP IL: X, Y, and Z are three borehole drilling sites. Borehole X passes through a thin coal seam at a depth of 50 in, while boreholes Y and Z reach the seam at 10 m and 40 m respectively.
Construct the structure contours for the coal seam and determine the strike and dip values using the right-hand rule. Show your steps: (5 marks)
Map the outcrops of this coal seam. (4 marks)
The drilling company is planning to add another borehole at either Point D or E to reach this coal seam. Which point should they pick? At the chosen point, at what depths should they expect to reach the coal seam? (4 marks)
The drilling company should add the borehcle at Point and should expect to reach
the coal seam at this location at a depth of in.
MAP 2: Label on the map, if any, all unconformities present. (2 marks)
In the space below, construct a geological cross section between X and Y. Label all geological formations and features clearly. (8 marks)
What is the vertical exaggeration of this cross-section? (2 marks)
limestone Mudstone Shale Siltstone
N
Sandstone Coal seam Sandy shale Conglomerate
0 metres 500 FO 0~ SCAU
-: - -' —Lo 1
L
0 I to---- - -
le t
00\
00
00
\0 0 0
0 1100
o0 -
.....
10 00
(m)
500
X Y
17 of' 19
This page is intentionally blank.
18 ol' 19
Note: This page is for sketching purpose. You may detach it for use during the exam, but anything written on this page will NOT be graded.
19 of 19