Chapter 12 - Geologic Time

Use the diagram and relative dating to determine what is the oldest layer. 

• The bottom layer will contain the oldest fossils
• The top layer will contain the oldest fossils
• It is impossible to tell which layer contains the oldest fossils with out absolute dating
• Layer A and C contain fossils from the same period

The attached image shows the Grand Canyon. The Unkar Group shows an areas where there may have been some folding and faulting. Choose the best answer to explain what impact this may have on dating the fossils in this layer.

• This may cause items dated in this layer to be incorrectly dated if the scientist only uses relative dating.
• Scientists must take into consideration the folding and faulting that is happening in this image when dating the layers.
• The most accurate way to date this layer of rock would be to use absolute dating.
• The most accurate way to date the fossils would be to use the Law of Superposition

What does carbon-14 decay into?

• Nitrogen
• Lead
• Uranium
• Cobalt

Which of the following is an index fossil?

• brachiopods
• tyrannosaurus rex
• coprolites
• trilobites

___________ states that the earth has changed gradually over long periods of time.

• uniformitarianism
• catrastorphism
• superposition
• disconformities

___________ is the idea that the earth changes very rapidly over short periods of time.

• uniformitarianism
• catrastorphism
• superposition
• disconformities

Most fossils are found in __________ rock layers

• metamorphic
• sedimentary
• igneous

_________ fossils can be found in tar, amber, deserts, and ice.

• trace
• original remains
• petrified
• cast

What is the half life of carbon-14?

• 10,000 years
• 5,730 years
• 2,135 years
• 1,025 years

Which of the following would carbon dating not be used for?

• bones
• teeth
• rock