front 1 Which of the following energy sources is thought to drive the lateral motions of Earth's lithospheric plates? | back 1 export of heat from deep in the mantle to the top of the asthenosphere |
front 2 During the ________ era, the westward-moving North American plate began to override the Pacific plate, eventually causing the tectonic activity that ultimately formed the mountains of western North America. | back 2 Mesozoic |
front 3 In the late 1700s James Hutton published his important work titled ________. | back 3 Theory of the Earth |
front 4 A worm would stand a poor chance of being fossilized because ________. | back 4 worms have no hard parts |
front 5 ________ was never proposed as evidence supporting the existence of Pangaea. | back 5 Islands of Precambrian rocks along the Mid-Atlantic Ridge |
front 6 Which period is known as the "age of fishes"? | back 6 Devonian |
front 7 The dense core of Earth is thought to consist predominantly of ________. | back 7 iron |
front 8 Which of the following refers to the investigative process by which geologists identify and match sedimentary strata and other rocks of the same ages in different areas? | back 8 correlation |
front 9 About 88 percent of geologic time is represented by the time span called the ________. | back 9 Precambrian |
front 10 The composition of the Earth's inner core is thought to be ________. | back 10 solid iron-nickel alloy |
front 11 Early results of the Deep Sea Drilling Project clearly justified the conclusion that ________. | back 11 the ocean basins are relatively young; no seafloor with an age in excess of 180 million years was ever found |
front 12 The former late Paleozoic supercontinent is known as ________. | back 12 Pangaea |
front 13 The study of Earth's atmosphere is known as ________. | back 13 meteorology |
front 14 Most of our knowledge about Earth's interior comes from ________. | back 14 seismic waves |
front 15 The era of "ancient life" is the ________ era. | back 15 Paleozoic |
front 16 Which one of the following represents the greatest expanse of geological time? | back 16 Precambrian |
front 17 Mammals became the dominant land animals during the ________ era. | back 17 Cenozoic |
front 18 The process in which plants use light energy to synthesize food sugars from carbon dioxide is called ________. | back 18 photosynthesis |
front 19 All of the following are possible steps of scientific investigation except for ________. | back 19 assumption of conclusions without prior experimentation or observation |
front 20 Catastrophism ________. | back 20 helped man understand the true nature of the forces that shaped the Grand Canyon |
front 21 During the Cenozoic, plate interactions gave rise to many events of mountain building, volcanism, and earthquakes in ________ North America. | back 21 western |
front 22 In correct order from the center outward, Earth includes which units? | back 22 inner core, outer core, mantle, crust |
front 23 A ________ is a well-tested and widely accepted view that best explains certain scientific observations. | back 23 theory |
front 24 What is the source of the energy that powers the Earth system? | back 24 both A and B |
front 25 Assume that you have just examined several flat-lying sedimentary layers. After much study you determine that there is a considerable span of time for which no sedimentary rock layer exists at this site. You have just discovered a(n) ________. | back 25 disconformity |
front 26 The ________ means "the Sun in the making." | back 26 protosun |
front 27 Which one of the following statements about the crust is NOT true? | back 27 Oceanic crust is enriched in potassium, sodium, and silicon. |
front 28 Visualize five horizontal sedimentary strata exposed in a cliff or canyon wall identified by consecutive numbers, 1 being the lowest bed and 5 being the highest. Which of the following statements concerning the strata are true? | back 28 Beds l and 3 are older than bed 4. |
front 29 The ________ era is known as the "age of flowering plants." | back 29 Cenozoic |
front 30 The average composition of the continental crust most closely approximates that of ________. | back 30 basalt |
front 31 The ________ is the thinnest layer of the Earth. | back 31 crust |
front 32 One group of reptiles, exemplified by the fossil Archaeopteryx, led to the evolution of ________. | back 32 birds |
front 33 The age of Earth is about ________. | back 33 4.5 billion years |
front 34 Which of the following gases was NOT part of Earth's original atmosphere? | back 34 both water vapor and nitrogen |
front 35 The ________ is thought to be a liquid, metallic region in the Earth's interior. | back 35 outer core |
front 36 In the early part of the twentieth century, ________ argued forcefully for continental drift. | back 36 Alfred Wegener |
front 37 The major source of free oxygen in the atmosphere is from ________. | back 37 green plants |
front 38 The first true terrestrial animals were the ________. | back 38 reptiles |
front 39 Which era is sometimes called the "age of dinosaurs?" | back 39 Mesozoic |
front 40 The ________ is the idea or concept that ancient life forms succeeded each other in a definite, evolutionary pattern and that the contained assemblage of fossils can determine geologic ages of strata? | back 40 principle of fossil succession |
front 41 The most common Precambrian fossils are ________, layered mounds of calcium carbonate. | back 41 none of these a. prokaryotes b. trilobites c. chert d. eukaryotes |
front 42 The ________ area geologically old mountain range folded and deformed during the Paleozoic. | back 42 Appalachians in the eastern United States |
front 43 Abundant fossil evidence did not appear in the geologic record until about ________. | back 43 540 million years ago |
front 44 The ________ explains how our solar system probably formed from a giant cloud of gases and dispersed solid particles. | back 44 nebular theory |
front 45 The waste gas released by plants as they synthesize food sugars from carbon dioxide and water is ________. | back 45 oxygen |
front 46 What is the age of the Earth accepted by most scientists today? | back 46 4.5 billion years |
front 47 The lithosphere is defined as ________. | back 47 a rigid layer of crustal and mantle material |
front 48 Who is credited with formulating the doctrine of uniformitarianism? | back 48 Hutton |
front 49 The ________ period was a time of major extinctions, including 75 percent of amphibian families. | back 49 Permian |
front 50 What are the basic differences between the disciplines of physical and historical geology? | back 50 Historical geology involves the study of rock strata, fossils, and geologic events, utilizing the geologic time scale as a reference; physical geology includes the study of how rocks form and of how erosion shapes the land surface. |
front 51 The supercontinent of Pangaea began to break up during the ________ era. | back 51 Mesozoic |
front 52 Consider the names of the eras in the geologic time scale. What is meant by "zoic"? | back 52 life; living things |
front 53 By the close of the Paleozoic, all the continents had fused into the single super continent of ________. | back 53 Pangaea |
front 54 The ________ refers to the sum total of all life on Earth. | back 54 biosphere |
front 55 The subdivision of the geologic time scale that represents the longest time span is called a(n) ________. | back 55 eon |