Exam 24: Geologic Time

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

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

The concept of uniformitarianism was developed by ______________, the "father of geology."

A group of periods is called a(n)

The study of fossils is called

Atomic nuclei that decay of their own accord are said to be ______________.

Because sediments are not deposited continuously in a given locality over time, breaks called ______________ occur in the rock record.

The oldest era in the Phanerozoic eon is the ______________ era.

The Mesozoic is a(n)

Fossils that are useful in correlating rock layers are called

The Petrified National Forest is found in the state of ______________.

Geologists have principally used which class of rocks for radiometric dating?

The Pliocene is a(n)

The Quarternary is a(n)

We live in the epoch called the

The Cenozoic era began about how many million years ago?

The Petrified National Forest is found in the state of

The term age of ancient life is sometimes used to refer to the ______________ era.

We live in the ______________ eon.

The Permian is a(n)