You have collected some samples while examining local rocks. You decide to have them analyzed at WSU using radiometric age dating.

1.You have collected some samples while examining local rocks. You decide to have them analyzed at WSU using radiometric age dating. Your analysis returns and says that 25% of the parent isotope remains in your rock samples. How many half lives have elapsed?

A.3 half lives

B.1 half life

C.0.5 half lives

D.2 half lives

2.If the half-life for the isotope in question 9 is 100,000 years, how old is your rock?

A.300,000 years old

B.100,000 years old

C.200,000 years old

D.50,000 years old

In cross-section 1, which principle of relative dating best indicates the relative age of the quartz vein?

A.cross cutting relationships

B.original horizontality

C.lateral continutity

D.superposition

In cross-section 1, what type of unconformity exists between the granite and conglomerate?

A.nonconformity

B.conformity

C.angular unconformity

D.disconformity

In cross-section 2, what type of unconformity exists between the basalt and glacial till?

A.angular unconformity

B.nonconformity

C.conformity

D.disconformity

In cross-section 2, which principle of relative dating best indicates where the oldest rocks are found?

A.cross cutting relationships

B.lateral continutity

C.superposition

D.original horizontality

• Attachment 1
• Attachment 2