Chapter 8: The Rock Record

The principle that a fault or body of rock is younger than any other body of rock that it cuts through is known as what?

• relative age
• law of crosscutting relationships
• varve
• law of super position

The time required for half of a sample of a radioactive isotope to break down by radioactive decay to form a daughter isotope is called what?

• uniformitarianism
• relative age
• half-life
• radioactive dating

The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock

• varve
• index fossil
• trace fossil
• fossil

Which of the following is a method of determining the absolute age of an object by comparing the relative percentages of a radioactive (parent) isotope and a stable (daughter) isotope?

• radiometric dating
• uniformitarionism
• law of superposition
• paleontology

A principle that geologic processes that occurred in the past can be explained by current geologic processes is called...

• paleontology
• law of superposition
• relative age
• uniformitarianism

The age of an object in relation to the ages of other objects is known as what?

• relative age
• absolute age
• half-life
• unconformity

What is the scientific study of fossils called?

• uniformitarianism
• unconformity
• paleontology
• radiometric dating

The principle that a sedimentary rock layer is older than the layers above it and younger than the layers below it if the layers are not disturbed is called ...

• unconformity
• law of crosscutting relationship
• law of superposition
• varve

What is a fossilized mark that formed in sedimentary rock by the movement of an animal on or within soft sediment called?

• index fossil
• fossil
• trace fossil
• varve

A break in the geologic record created when rock layers are eroded or when sediment is not deposited for a long period of time is called what?

• law of crosscutting relationships
• unconformity
• radiometric dating
• varve