Relative and Absolute Dating Review

Relative dating principle shown in the image

• Cross-cutting relationships
• Inclusions

• Superposition
• Absolute dating

Tags

NGSS.MS-ESS1-4

Which of the following is an example of a crosscutting relationship?

• A fold in a rock layer
• A volcanic eruption
• A river eroding a canyon
• A fault or intrusion cutting through layers of sedimentary rock

Carbon-14 has a half life of 5,730 years. A fossilized rock originally contained 200 grams of Carbon-14. When tested, the rock only contains 50 grams of Carbon-14. Approximately how old is the item?

• Approximately 11,460 years old
• Approximately 5,700 years old

• Approximately 1,000 years old
• Approximately 20,000 years old

Tags

NGSS.HS-PS1-8

Iodine-131 has a half life of 8 days. How much iodine would be left after 8 days if the original sample had 40 grams?

• 10 grams
• 30 grams
• 5 grams
• 20 grams

Tags

NGSS.HS-PS1-8

Carbon-14 is often used for radioactive dating, but it has its limitations. Uranium-238 or lead-206 are most often used to date rocks. Why would U-238 or Pb-206 be more useful than C-14 when dating rocks?

• Uranium-238 or lead-206 have longer half-lives.

• Uranium-238 or lead-206 are not commonly found in rocks.
• Carbon-14 is more accurate than Uranium-238 or lead-206 in dating rocks.
• Uranium-238 or lead-206 have shorter half-lives and are less stable isotopes.

An intrusion or break is always younger than the rock it cuts across describes which relative dating principle?

• Principle of original horizontality
• Principle of cross-cutting relationships
• Principle of faunal succession
• Principle of superposition

The older layers of rock are always on the bottom, and the newer, younger ones on are top describes which relative dating principle?

• Law of Original Horizontality
• Law of Superposition
• Law of Inclusion
• Law of Cross-Cutting Relationships

Layers of sediment are deposited in horizontal layers describes which relative dating principle?

• Principle of original horizontality
• Principle of superposition
• Principle of cross-cutting relationships
• Principle of lateral continuity

If another rock is inside a rock layer, it is "included" and usually older than the layer it cut through describes which relative dating principle?

• Principle of Cross-Cutting Relationships
• Principle of Inclusion
• Principle of Superposition
• Principle of Original Horizontality

Gaps in the geologic record as characterized by erosion describes which relative dating principle?

• Principle of superposition
• Principle of original horizontality
• Principle of cross-cutting relationships
• Principle of unconformities