Which of the following energy sources is thought to drive the lateral motions of Earth's lithospheric plates?
export of heat from deep in the mantle to the top of the asthenosphere
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.
In the late 1700s James Hutton published his important work titled ________.
Theory of the Earth
A worm would stand a poor chance of being fossilized because ________.
worms have no hard parts
________ was never proposed as evidence supporting the existence of Pangaea.
Islands of Precambrian rocks along the Mid-Atlantic Ridge
Which period is known as the "age of fishes"?
The dense core of Earth is thought to consist predominantly of ________.
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?
About 88 percent of geologic time is represented by the time span called the ________.
The composition of the Earth's inner core is thought to be ________.
solid iron-nickel alloy
Early results of the Deep Sea Drilling Project clearly justified the conclusion that ________.
the ocean basins are relatively young; no seafloor with an age in excess of 180 million years was ever found
The former late Paleozoic supercontinent is known as ________.
The study of Earth's atmosphere is known as ________.
Most of our knowledge about Earth's interior comes from ________.
The era of "ancient life" is the ________ era.
Which one of the following represents the greatest expanse of geological time?
Mammals became the dominant land animals during the ________ era.
The process in which plants use light energy to synthesize food sugars from carbon dioxide is called ________.
All of the following are possible steps of scientific investigation except for ________.
assumption of conclusions without prior experimentation or observation
helped man understand the true nature of the forces that shaped the Grand Canyon
During the Cenozoic, plate interactions gave rise to many events of mountain building, volcanism, and earthquakes in ________ North America.
In correct order from the center outward, Earth includes which units?
inner core, outer core, mantle, crust
A ________ is a well-tested and widely accepted view that best explains certain scientific observations.
What is the source of the energy that powers the Earth system?
both A and B
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) ________.
The ________ means "the Sun in the making."
Which one of the following statements about the crust is NOT true?
Oceanic crust is enriched in potassium, sodium, and silicon.
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?
Beds l and 3 are older than bed 4.
The ________ era is known as the "age of flowering plants."
The average composition of the continental crust most closely approximates that of ________.
The ________ is the thinnest layer of the Earth.
One group of reptiles, exemplified by the fossil Archaeopteryx, led to the evolution of ________.
The age of Earth is about ________.
4.5 billion years
Which of the following gases was NOT part of Earth's original atmosphere?
both water vapor and nitrogen
The ________ is thought to be a liquid, metallic region in the Earth's interior.
In the early part of the twentieth century, ________ argued forcefully for continental drift.
The major source of free oxygen in the atmosphere is from ________.
The first true terrestrial animals were the ________.
Which era is sometimes called the "age of dinosaurs?"
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?
principle of fossil succession
The most common Precambrian fossils are ________, layered mounds of calcium carbonate.
none of these
The ________ area geologically old mountain range folded and deformed during the Paleozoic.
Appalachians in the eastern United States
Abundant fossil evidence did not appear in the geologic record until about ________.
540 million years ago
The ________ explains how our solar system probably formed from a giant cloud of gases and dispersed solid particles.
The waste gas released by plants as they synthesize food sugars from carbon dioxide and water is ________.
What is the age of the Earth accepted by most scientists today?
4.5 billion years
The lithosphere is defined as ________.
a rigid layer of crustal and mantle material
Who is credited with formulating the doctrine of uniformitarianism?
The ________ period was a time of major extinctions, including 75 percent of amphibian families.
What are the basic differences between the disciplines of physical and historical geology?
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.
The supercontinent of Pangaea began to break up during the ________ era.
Consider the names of the eras in the geologic time scale. What is meant by "zoic"?
life; living things
By the close of the Paleozoic, all the continents had fused into the single super continent of ________.
The ________ refers to the sum total of all life on Earth.
The subdivision of the geologic time scale that represents the longest time span is called a(n) ________.