LHS Relative and Absolute Dating

According to the law of superposition, the oldest fossils are found 

• At the top of the rock layers
• Near the bottom of the rock layers
• In the middle of the rock layers
• Somewhat near the surface

Gaps in rock layers caused by erosion are called

• law of superposition
• unconformities
• uniformitarianism
• relative dating

Which type of dating method can be used on rock layers by applying the Law of Superposition?

• relative dating
• absolute dating
• radioactive dating
• radiometric dating

The ________ states that layers of sediment were originally deposited horizontally under the action of gravity.

• law of superposition
• law of horizontality 
• uniformitarianism 
• unconformities

This states that the geologic feature which cuts another is the younger of the two features

• law of horizontality
• cross cutting relationships
• law of superposition
• uniformitarianism

What 2 things make a good index fossil?

• Good looks and a great smile
• widespread and on Earth of a short time
• widespread and on Earth for a long time
• only found in Clinton Twp and in every rock layer

Which of the following is the oldest?

• Layer L
• Intrusion D
• Intrusion H
• Layer E

What happens during radioactive decay?

• A stable isotope of one element changes into an unstable isotope of a different element
• A stable isotope of one element changes into an unstable isotope of the same element
• An unstable isotope of one element changes into a stable isotope of a different element
• An unstable isotope of one element changes into a stable isotope of the same element

How many of the original atoms of a decaying isotope remain unchanged after three half-lives?

• three-halves
• three-quarters
• one-quarter
• one-eighth

Why are isotopes with short half-lives not useful for dating very old rocks?

• because not enough of the parent isotope remains to measure accurately
• because not enough of the daughter product has formed to be detectable
• because neither the parent isotope nor the daughter product will be detectable
• because very old rocks would never have contained these isotopes