CRISES OF A PLANET - GEOL 108 September 21, 2010Midterm 1 – VERSION A Maximum Points = 300A. TRUE/FALSE (2 points each) Designate which statements are TRUE or FALSE by filling in the A (true) or B (false) blank on the SCANTRON answer sheet.1. Heating of the inner portions of Earth result from fusion of hydrogen atoms. 2. Other than trace amounts of He, early planet Earth had no atmosphere at the time of its formation.3. The terrestrial planets, including Mercury, Venus, Earth and Mars, are enriched in iron, magnesium, silicon, and oxygen relative to the larger more distant planets.4. The age of light coming to earth from the most distant regions of the universe dates back to about12 to 14 b.y. ago, the estimated age of the "Big Bang".5. The Solar System is expanding today.6. Water on planet Earth initially arrived from comets. 7. Without radioactivity the Earth, would be a dead planet.8. Island arcs result from convergence of two ocean plates.9. Early earth destroyed its crust much like is occurring in the oceans today. 10. Ocean crust is youngest at the ocean ridges where it is formed and becomes progressively older with distance from the ridge.11. Primary waves cause the first shaking in an earthquake 12. Transform faults connect ends of offset ocean ridges.13. Pangea formed from a number of continental collisions leading to the formation of the Sierra Nevada and San Gabriel Mountains.14. Rifting of Pangea resulted in the formation of Laurasia and Gondwanaland.15. The present site of the Ural Mountains represents the demise of a long-lost ocean basin.16. The San Andreas fault is a boundary between the North American and Pacific plates, the latter presently moving northward toward the Aleutian trench.17. The fluid motion of the outer core is the cause of the Earth's magnetic field. 18. The Earth's early atmosphere resulted from volcanic activity.19. Convergence of two ocean plates leads to the construction of island arcs such as the Aleutians, theTonga Islands, and Japan.20. Most of the Earth's seafloor has been recycled back into the mantle.21. As early as 1911, Alfred Wegener presented ideas about sea floor spreading.22. Ocean crust is primarily comprised of basalt and related igneous rocks.23. Pahoehoe is a Hawaiian term applied to pyroclastic basalt eruptions.24. The port town of St. Pierre, on the Caribbean Island of Martinique, was destroyed by a nuee ardente.25. Ocean crust melts during subduction forming andesite magma, the dominant volcanic rock of island arcs.26. Andesite magma is a more viscous liquid than that of basalt because it contains more silica and isat a lower temperature.27. Volcanic activity of the Cascade Mountain Range of the Pacific Northwest results from continental collision28. Valley widening primarily occurs by mass wasting.29. Rock debris at the bottom of a rock fall is known a talus. 30. Mud flows have the capacity to become airborne. B. MULTIPLE CHOICE (3 points each) Use the SCANTRON sheet, beginning with number 51.51. Using the “rule of 70”, a population growth rate of 2% would lead to a doubling of the world’s population in a) 140 years d) 35 yearsb) 70 years e) 2 yearsc) 68 years52. Edwin Hubblea) confirmed the theory of an expanding universe.b) originated the theory of plate tectonics.c) described a model for the origin of the Solar System.d) observed "noise" on an unused TV channel.e) is the author of your textbook.53. The early Earth's atmosphere is mostly made ofa) oxygen, carbon, and waterb) carbon dioxide, hydrogen sulfide or sulfur dioxide, and waterc) nitrogen and oxygend) methane and butane.54. Our Earth is a unique planet in the Solar System due to:a) the presence of an atmosphere which filters out dangerous ultraviolet radiation and inhibits temperature variations.b) its distance from the Sun which dictates its overall chemical composition and average temperature.c) its size, which allows just the right amount of gravity to hold an atmosphere conducive to life.d) the presence of radioactive elements which fuel volcanism and related tectonics.e) all of the above.55. The giant outer planets (Jupiter, Saturn, Uranus, and Neptune)a) are all cold and geologically dead.b) have high values of density.c) are composed of hydrogen (H), helium (He), water (H2O), methane (CH4), sulfur (S), ammonia (NH3), and carbon oxides (CO, CO2) amongst other light elements and compounds.d) are expanding. e) all of the above.56. Early heating of the Earth 2a. formed the core and mantleb. melted iron and some nickelc. led to the formation of the magnetic fieldd. occurred soon after planetary formatione. all of the above57. Early life on Eartha. began in the oceans.b. dates back to at least 3.8 billion years.c. was of one-celled bacteria and algae.d. began in divergent plate boundary.e. all of the above.58. The greatest extinction occurred at a. late Ordovician timeb. late Devonian timec. the Permian – Triassic boundary d. the Triassic – Jurassic boundary e. the Cretaceous – Tertiary boundary 59. Humans on eartha. as Homo Sapien date back to 2 million years.b. did not have a population of about 1 billion until the year 1830. c. emerged during the Ice Age.d. settled the America’s the last 15,000 years. e. all of the above. 60. The current human population on our planet isa. 1 to 2 billionb. 2 to 4 billionc. 4 to 5 billiond. 6 to 7 billione. 10 to 12 billion61. Relative to the age of the Earth, the fraction of time that humans have existed is a) 50 %.b) 25 %.c) 12%.d) 1 %.e) 0.04 %.62. The Wilson Cycle includesa) sedimentation-metamorphism-melting.b) rifting-subduction-collision.c) subsidence-uplift-erosion.3d) none of the above.63. The asthenospherea) occurs deep within the crust of the earth.b) overrides the lithosphere in regions of the Earth except for subduction zones.c) is the name for a non-spherical planetary body.d) is the principle cause of plate tectonics on Earth. e) is composed of nitrogen and oxygen.64. The Sierra Nevada Mountainsa) are mostly comprised of granite.b) represent the igneous roots of an Andean-type volcanic arc.c) are testimony that subduction that once existed beneath California.d) contain remnants of island arcs.e) all of the above.65. The average rate of sea floor spreading is:a) 6mm/yr.b) 6cm/yr.c) 6cm/100 yrs.d) 6cm million yrs.e) none of the above.66. Continental collision results in:a) a double thickness of continental crust.b) the formation of unusually high