Exam 24: Geologic Time

Fossilized tree resin is called ______________.

We live in the period called the

In which of the following eons do we live?

A group of periods is called a(n)

Which of the following is not a feature of a good index fossil?

Fossils that are useful in correlating rock layers are called

Which of the following is a period of the Cenozoic era?

If a rock sample contains uranium and lead, and lead-204 is present, then

The Cenozoic is a(n)

The Cambrian is a(n)

Layers of sediment, lava, and ash are originally laid down in a(n) ______________ position.

The Cenozoic era consists of only two periods: the ______________ and the Quaternary.

Eons are divided first into

The Eocene is a(n)

The Cenozoic era consists of the Tertiary and ______________ periods.

Which of the following radionuclides is used to date once-living material?

The earliest evidence of prehistoric life is the single-celled organisms called ______________.

Relative and absolute geologic times are combined to give the ______________ scale.

The hollow depression left when a shell or bone is dissolved completely out of a rock is called a(n)

Wood from an ancient stump has a ratio of carbon-14 to carbon-12 that is one-eighth that of new wood. About how old is the stump? (Carbon-14's half-life is 5730 years.)