Geological History/ Relative vs Absolute Dating

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

Letter "F" is a....

• inclusion
• intrusion
• fault
• unconformity 

All plants and ANIMALS contain carbon.

• True
• False

How old is the Earth?

• 4.6 billion years
• 1.4 billion years
• 4.6 million years
• 6000 years

Traces or remains of organisms that lived long ago

• Fossil
• Unconformity
• Superposition
• Column

According to the law of superposition, which layer is the youngest?

• A
• B
• C

If the half-life of a radioactive group of atoms is 100 years, then how old is the rock if there have been two half-lives?

• 25 years
• 200 years
• 400 years
• 800 years

Tags

CCSS.HSF.LE.A.4

The time it takes for 50% of the nuclei in a radioactive sample to decay to its stable isotope is called _____.

• the daughter product
• geologic time
• the half-life
• the half-time

A break in the geologic record that is made when rock layers are eroded over a long period of time

• Law of Superposition
• Law of Crosscutting
• Relative Dating
• Unconformity

How does the law of crosscutting explain the age of a fault?

• The fault is younger than the rocks above it.
• The fault is younger than the rocks it cuts through.
• The fault is older than the rocks above it.
• The fault is older than the rocks it cuts through.