Earth Science – Third midterm review (Geology) – Spring 2008

Terms:

cleavage mineral Mohs hardness scale silicate carbonate silicon-oxygen tetrahedron oxide coarse-grained texture chemical sedimentary rock contact metamorphism detrital sedimentary rock evaporite extrusive (volcanic) fine-grained texture foliated texture glassy texture igneous rock intrusive (plutonic) lava lithification magma metamorphic rock nonfoliated texture regional metamorphism rock cycle sediment sedimentary rock

weathering chemical weathering frost wedging mechanical weathering parent rock surface area aftershock crust earthquake elastic rebound epicenter fault focus inner core liquefaction magnitude mantle outer core P wave Richter scale S wave tsunami seismograph surface wave continental drift volcanic arc convergent boundary

divergent boundary mid-ocean ridge deep sea trenches Pangea plate tectonics rift valley seafloor spreading subduction transform boundary aa flow cinder cone composite cone pahoehoe flow pyroclastic shield volcano viscosity volcano half-life cross-cutting relationships relative dating numerical dating superposition original horizontality parent isotope daughter isotope radiometric dating uniformity catastrophism

Review questions:

1. What information does a chemical formula give?

2. What are the 8 most common elements in Earth’s crust?

3. What is the geologic definition of a mineral?

4. What are three families of minerals? What is distinguishing about these mineral families? Which mineral family is the most abundant on Earth?

5. What is the basic structure of all silicate minerals? What elements make up this structure?

6. How do silicate mineral groups increase in complexity related to bonding of silicate tetrahedral?

7. What are various ways we can identify minerals? Can you give an example?

8. What is the rock cycle? (can you draw it?)

9. Briefly, what are the three families of rocks, and how do we define them, generally?

10. Where do we find igneous rocks? What terms do we call igneous rocks that er found at and beneath the surface?

11. By what two criteria can we identify most igneous rocks?

12. What are differences between mafic and felsic magmas and rocks?

13. What are other textures (besides grain size) that are common in igneous rocks?

14. What are three basic types of volcanoes? What are differences between these volcanoes? What are examples of these types of volcanoes?

15. In which types of crust do the two different compositions of magma occur?

16. What are some types of basaltic lava flows?

17. What are some types of pyroclastic fragments?

18. What are the various types of weathering?

19. What are examples of physical weathering? Chemical weathering?

20. What are the two main categories of sedimentary rock?

21. What are the varieties of detrital sediment and their corresponding sedimentary rocks?

22. What two processes go into lithification?

23. What does sediment size indicate about the energy of the environment?

24. What are specific examples of high and low energy environments?

25. What are some chemical sedimentary rocks, and how does each generally form?

26. What are some features other than grain size that might be found in sedimentary rocks?

27. What are the two main types of metamorphism? How do they occur

28. What texture is associated with each?

29. What are some examples of foliated textures and the rocks associated with each?

30. What degree of metamorphism is represented by each foliated texture?

31. What are examples of the relationship between parent rock and metamorphic rock? Examples?

32. What are examples of contact metamorphism?

33. Who developed the theory of continental drift?

34. What were his observations that supported his theory?

35. What mechanism did he propose to drive continental drift?

36. Why were his ideas not accepted?

37. After Wegener, where did geologists generally find new information to modify Wegener’s theory?

38. What are the three basic types of plate boundaries? What are examples of each?

39. Give specific types of convergent and divergent margins.

40. How is volcanic activity related to subduction?

41. What is the relative age of the ocean floor compared to the continents?

42. Where is the oldest ocean crust? Youngest?

43. What patterns does one find in the ages of ocean crust?

44. What mechanism drives plate tectonics?

45. What is convection?

46. How do earthquakes occur?

47. What types of seismic waves do earthquakes generate? Which is fastest? Which causes the most damage?

48. Which seismic waves help to pinpoint an earthquakes location?

49. What is amplitude?

50. What is the difference in amplitude with each increment increase in an earthquakes magnitude? The difference in energy?

51. What are major source of damage in earthquakes?

52. What are the major layers of Earth’s interior?

53. How do we know where these layers are despite never having seen the actual rocks from those depths?

54. Which layer is completely liquid?

55. Geologists now generally accept that Earth is how old?

56. What principle did James Hutton devise to study the geologic history of rock exposures he found in the field?

57. This principle was at odds with another perspective for studying geologic history. What was that principle called? And what was this principle?

58. What are the two types of geologic age dating? What are the differences between the two?

59. How is relative age dating done?

60. How is absolute age dating done?

61. What are radiometric (unstable) isotopes?

62. What is the order of geologic time periods from the Cambrian to the present? What is a mnemonic device to help you remember the geologic time periods?

63. Explain how the property of density affects processes found in each of the fields of Earth Science that we’ve covered.

64. Give examples of convection in at least three of the four fields of Earth Science that we’ve covered. Explain a little about each of these convective processes.