Exam 24: Geologic Time

The Mesozoic era began about how many million years ago?

The time before the Phanerozoic eon is collectively called ______________ time.

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.)

Paleontology is the study of

The K-T event occurred about ______________ million years ago.

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

Naturally occurring uranium ultimately decays to isotopes of the element named ______________.

If a rock sample contains uranium and lead, but no lead-204 is present, then

New material filling a mold forms a(n) ______________ of the original shell or bone.

Which of the following eons is the oldest?

A group of eras are called a(n)

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

In which of the following eons do we live?

Trilobites lived during which era?

The oldest evidence of life on Earth dates back to about how many years ago?

The largest units of geologic time are called ______________.

We live in the ______________ epoch.

Carbon dating was used to establish the age of the Shroud of ______________.

The Paleozoic era began about how many million years ago?

The largest units of geologic time are the