Earth's History in Rocks

Which best describes a fossil that helps determine the relative age of a rock layer?

• trace fossil
• index fossil
• radioactive fossil
• unconformity fossil

Which process would be most effective in determining the age of fossils embedded in rock?

• relative dating
• absolute dating
• use of index fossils
• use of core sampling

By which method have scientists determined that the Earth is about 4.5 billion years old?

• plate tectonics
• relative dating
• radioactive dating
• law of superposition

Which characteristic of carbon-14 dating helps scientists determine the approximate time a species became extinct?

• Carbon-14 is not present in more recent fossils
• Carbon-14 increases at a constant rate over time
• Carbon-14 decreases at a constant rate over time
• Carbon-14 can only be found in fossils of a certain period

Which is the most accurate method scientists can use to estimate Earth's age?

• relativism
• superposition
• relative dating
• radioactive dating

The index fossil of a type of trilobite is discovered in layer A of a set of rock layers found at three different sites of a field investigation. Which conclusion can be made about the rocks in layer A at all three sites?

• The rocks are all different ages
• The rocks are all about the same age
• The rocks were formed from melting magma
• The rocks were formed during a catastrophic event

Which statement is true?

• The oldest layers of rock and soil are closest to the surface of the earth
• The youngest layers of rock and soil are farther away from the surface of the earth.
• Carbon-14 dating is an example of relative dating, and the law of superposition is an example of absolute dating.
• Absolute geologic dating and relative geologic dating are two methods used by scientists to determine the age of geologic evidence.

Which method provides the most accurate age of a rock sample?

• superposition
• relative dating
• radioactive dating
• index fossil identification

Which type of rock replaces bone and other hard organic materials to create rock molds of fossils?

• metamorphic
• sedimentary
• extrusive igneous

Rich beds of marine fossils have been found in Florida. By dating these fossils, scientists can best determine

• when Florida collided with the North American continent.
• the date when organisms moved onto dry land.
• the period during which Florida was covered in water.
• when the atmosphere of Earth was more humid than it is today.