GLY2010 Physical Geology, Fall, 2012 SECOND MID-TERM EXAMINATION Test No. 0001 Name: _____________________ Class Time: 10am noon (circle one) READ THIS!!!! Put your name in the blank above. Read all questions carefully, and answer only the question which is asked. PLEASE WRITE NEATLY. Matching: Do not put on the scantron sheet. (8 pts) 1. ____ dip A. calculating age in years. 2. ____ isostacy B. correlation based on fossils. 3. ____ shadow zone C. erosional part of the continental margin. 4. ____ relative dating D. angle between a geologic feature and horizontal. 5. ____ absolute dating E. age of something in comparison to something else. 6. ____ biostratigraphy F. part of continental margin where sediment from above is deposited. 7. ____ continental rise G. location where no seismic energy from a distant earthquake is received. 8. ____ continental slope H. the crust floats on the mantle at a height determined by density and thickness. Multiple Choice: (2 pts each) Put the answers to these questions on the scantron sheet. 1. The erosional features seen in Figure 1 (represented by the wiggly line), are, respectively: a. nonconformity, disconformity, angular unconformity. b. disconformity, angular unconformity, nonconformity. c. angular unconformity, disconformity, nonconformity. d. nonconformity, angular unconformity, disconformity. e. disconformity, nonconformity, angular unconformity. 2. The man who, in suggesting that slow and steady ordinary processes (rather than sudden and catastrophic processes) can produce what we see on earth, observed that there was, "No vestige of a beginning, no prospect of an end" was: a. Lord Kelvin. b. James Hutton. c. Archbishop Ussher. d. Nicholas Steno. e. Ernest Rutherford. 3. The Principle of Relative Dating that tells us that sedimentary beds normally deposited with the youngest on top and oldest on the bottom is known as the Principle of: a. Original Horizontality. b. Cross Cutting Relationships. c. Lateral Continuity. d. Correlation. e. Superposition. 4. To calculate the radiometric age of a geologic material, we: a. multiply the number of half lives by the duration of the half life. b. multiply the duration of the half life by the fraction of remaining parent product. c. multiply the duration of the half life by the fraction of daughter product produced. d. divide the half life by the number of half lives. e. plot the percentage of remaining parent material, and the age is where it all decays away. 5. In which type of radioactive decay is a high speed electron emitted from the nucleus? a. radiocarbon b. electron capture c. fission track d. beta decay e. alpha decay 6. The statement, “This obsidian arrowhead was made 200 million years ago according to K/Ar dating” cannot be correct because: a. K/Ar dating cannot date materials that young. b. K/Ar dating will give the solidification age of the obsidian, not when the arrowhead was made. c. obsidian is a weathered material. d. K/Ar will only give a relative age, not an absolute age. e. radiometric dating is only good to 100 half lives, and 20 million years is much more than that. 1 7. Which of these rock types is most likely to give a reliable radiometric date? a. metamorphic. b. sedimentary. c. igneous. d. none of these. e. all of these. 8. Which of these statements about structural folds is false? a. the youngest rocks exposed in an eroded syncline will be in the center. b. folds are caused by compressive stress. c. synclines have the rock layers tilted towards the center. d. anticlines are upwardly folded rocks. e. folds occur due to brittle deformation. 9. We would expect which of these structural features to be formed in a divergent boundary? a. strike-slip faults. b. folds. c. grabens. d. structural domes. e. all of these. 10. The line representing the intersection of a horizontal plane with a dipping stratum is called the: a. strike. b. plunge. c. limb. d. dip. e. axis. 11. Which of these mountain building regions is undergoing tensional stress? a. Basin and Range. b. Appalachians. c. Mesas. d. Andes. e. Himalayas. 12. Which of these would lead you to conclude that you are walking over a structural dome? a. the rocks tilt towards the center. b. the center of the feature is higher. c. the center of the feature is lower. d. the age of the rocks is greater in the center. e. the age of the rocks is greater near the edges. 13. Seismic rays are bent due to changes in their velocity as they travel through the earth's interior. This phenomenon is called: a. reflection. b. diffraction. c. refraction. d. dispersion. e. liquefaction. 14. The presence of 3 seismometers at any one location allows us to: a. determine the depth of the focus of the earthquake. b. locate the epicenter of the earthquake. c. determine what kind of plate boundary the earthquake originated at. d. identify the material that fractured. e. identify the complete 3-dimensional movement of the earthquake. 15. A magnitude 4 earthquake causes how much more ground movement than a magnitude 2 earthquake? a. 2 times as much. b. 4 times as much. c. 10 times as much. d. 100 times as much. e. 400 times as much. 16. The name of the theory that explains how earthquakes occur is: a. Strike-Slide. b. Friction Lock. c. Elastic Rebound. d. Plastic Strain. e. Lock-Slip. 17. The discovery of the S-WAVE SHADOW ZONE allowed us to conclude that the: a. core is made of a material that slows S waves. b. outer core is liquid. c. inner core is iron. d. asthenosphere can plastically deform. e. mantle is composed of rocky silicate minerals. 18. Which one of the following was NOT evidence used by supporters of the CONTINENTAL DRIFT HYPOTHESIS? a. ancient glacial features. b. fossils. c. fit of the continents. d. rock type similarities on different continents. e. all of these were used. 19. What is the name of the Mesozoic Supercontinent that consisted of the present Southern Hemisphere continents? a. Pangaea b. Gondwanaland c. Laurasia d. Eurasia e. Panthalassa 20. The hypothesis of Plate Tectonics was first proposed around: a. 1500-1600. b. 1750-1800. c. 1910-1930. d. 1950-1970. e. 1980-2000. 2 21. Alfred Wegener's original hypothesis was REJECTED by scientists at the time because: a. the continents have not in fact moved. b. his data was fabricated. c. his data suggesting movement was unconvincing. d. he used other scientists' data. e. his proposed mechanism was shown to be impossible. 22. Marine Magnetic Anomalies were used to first identify: a. transform boundaries. b. divergent boundaries. c. all types of plate boundaries. d. ocean-ocean convergent boundaries. e. ocean-continent convergent boundaries. 23. In Figure 2, features of a typical ocean basin labeled 1, 2, 3, 4, and 5, respectively, are: a. active continental margin, deep ocean trench, mid-ocean ridge, abyssal plain, passive continental margin. b. divergent margin, mid-plate, convergent margin, divergent margin, convergent margin. c. active continental margin, transform, deep ocean trench, fracture zone, passive continental margin. d. passive continental margin, continental shelf, fracture zone, submarine canyon, transform margin. e. convergent margin, continental shelf, atoll, fracture zone, divergent margin. 24. Most of the features of the seafloor owe their existence and particular characteristics to: a. the original accumulation of the earth when it formed. b. meteorite impact. c. plate tectonics. d. coral growth. e. continental weathering. 25. Which of the features listed below are not formed entirely or partly by currents of sediment-laden seawater flowing down over the Continental Slope? a. deep ocean trenches b. abyssal plains. c. turbidites d. submarine canyons. e. all of these are caused by these currents. Non-Multiple Choice. You MUST do six and only six of questions 1-12 (7 pts each). 1. Hypothetically, suppose we have a radioactive isotope of 105Pd, (atomic number 46). Figure out what isotope (including atomic mass number and atomic number) will result when 105Pd undergoes each of the following types of decay: alpha decay, beta decay, electron capture. To help, a portion of the periodic table including Pd and several nearby elements is included below. Remember, you MUST show how you arrived at your answers. Alpha Decay: _______ Beta Decay: _______ Electron Capture: _______ Note: the number at the bottom of each square is the atomic weight, and will not be used in this problem. (Note: several lines available for this on the actual test) 2. Give a detailed explanation of the method that seismologists use to locate the epicenters of earthquakes. (Note: several lines available for this on the actual test) 3. For the following faults, folds, or other structural features, state the name of the feature, type of stress that caused it, and the type of plate boundary you would expect to see these features in. Number(s) Name (@ 1/2pt) type of stress (@1/4pt) plate boundary type (circle) (@1/4pt) . 1 _____________________ _____________________ divergent convergent transform 2 _____________________ _____________________ divergent convergent transform 3 _____________________ _____________________ divergent convergent transform 4 _____________________ _____________________ divergent convergent transform 5 _____________________ _____________________ divergent convergent transform 6 _____________________ _____________________ divergent convergent transform 7 _____________________ _____________________ divergent convergent transform 3 4. A volcanic rock is found to have a daughter isotope to parent radioactive isotope ratio of 3:1. If the half- life of the isotope is 5 million years, how old is the rock? Show all of your steps. (Note: several lines available for this on the actual test) 5. Explain in the context of sedimentary, erosional, igneous processes, or Plate Tectonics, how the following features form. Note: an answer simply naming a plate boundary such as "because it's a divergent boundary" is not sufficient.