Relative Dating
Absolute Dating
Vocabulary Terms
Geologic Divisions of Time
Types of Preservation
100
This is a definition for Relative Age Dating.
Answers will vary, but should be similar to: "What is the age of rocks and geologic features compared with other rocks and features nearby."
100
This is a definition for Absolute Age Dating.
Answers will vary, but should be similar to: "What is the numerical age, in years, of a rock or object?"
100
These are the preserved remains or evidence of ancient living things.
What is a fossil?
100
This is the largest division of Geologic Time.
What is an EON?
100
This type of fossil happens when minerals fill the spaces between an organisms tissues. Then the tissues decay and leave the minerals behind.
What is a Petrified Fossil?
200
This is the Principle of Superposition.
Answers will vary, but should be similar to: "What is in undisturbed rock layers, the oldest rocks are on the bottom."
200
How much of a Radioactive Isotope remains after one half life?
What is 50%, or 1/2?
200
These are atoms of the same element that have different numbers of neutrons.
What are Isotopes?
200
This is the smallest division of geologic time, excluding "Ages."
What is an Epoch?
200
This type of fossil is created when an organism becomes completely encased by a substance like tar or ice, that keeps the organism from decaying.
What are Preserved Remains?
300
Use the diagram of a rock wall to explain how the "Cloud" fossil relates to the "Lightning" fossil.
What is the Cloud Fossil is older than the Lightning Fossil?
300
How much of a radioactive isotope is remaining after two half-lives?
What is 25%, or 1/4?
300
This is the time required for half of a parent isotope to decay into a daughter isotope.
What is a half-life?
300
This geologic division of time is larger than an Epoch, but smaller than an Era.
What is an Period?
300
This type of fossil forms when gases and liquids are squeezed out of the organism by heat and pressure. It leaves only the Carbon Atoms behind.
What is a Carbon Film?
400
Use the diagram of the rock wall to tell how the "Star" fossil relates to the "Lightning" fossil.
What is the "Star" Fossil is younger than the "Lightning" fossil?
400
How much of a radioactive isotope has decayed after two half-lives?
What is 75% or 3/4?
400
These are species that existed on Earth for a short length of time, were abundant, and inhabited many locations.
What are Index Fossils?
400
This geologic Division of Time is larger than a Period, but is smaller than an Eon.
What is an Era?
400
This type of fossil is made when a mold gets filled in.
What is a Cast?
500
Using the diagram of a rock wall, describe three things about the Lightning Fossil.
What is the "Lightning" Fossil is older than the Star Fossil, but younger than the Cloud Fossil. The Lightning Fossil existed at the same time as both the Star Fossil and the Cloud Fossil.
500
Using the Half-Life Graph of Uranium 238 predict how old a sample is that contains 12.5% of the parent isotope.
What is 13,500 million years, or 13.5 billion years old?
500
This is the process of an unstable element naturally changing into another element that is stable.
What is Radioactive Decay?
500
This is how scientists decided where to place divisions in geologic time.
What are major changes to the fossil record?
500
This type of fossil does not contain the actual living thing. It is evidence that the living thing existed.
What is a Trace Fossil?