Geologic Time Goal A/B Vocabulary

Definition: a long and distinct period of history with a particular feature or characteristic.

• relative age

• era

• periods

• cambrian

Definition: Pre-Cambrian time covers from 4.6 billion to 544 million years ago. During this time life developed as bacteria and softbodied, multicelled organisms.

• Carboniferous Period

• Precambrian Time

• Geologic Time

• Mesozoic Era

Definition: A principle that geologic processes that occurred in the past can be explained by current geologic processes.

• gradualism

• uniformitarianism

• neptunism

• plutonism

What is a mass extinction?

• Just as eons are subdivided into eras, eras are subdivided into units of time called periods.

• Event during which many species become extinct during a relatively short period of time

• Era that began about 66 million years ago, known as the "Age of Mammals"

• A long and distinct period of history with a particular feature or characteristic.

What is this definition describing?

• Geologic time

• Geophysical flux

• Absolute time

• Relative age

Which era does this definition describe?

• Cenozoic Era

• Mesozoic Era

• Paleozoic Era

• Precambrian Era

Definition: the part of geologic time 570-245 million years ago; invertebrates, fishes, amphibians, reptiles, ferns, and cone-bearing trees were dominant.

• Mesozolc Era

• Paleozoic Era

• Precambrian Era

• Mezozolic Era

Definition: the largest division of geologic time.

• eras

• ern

• span

• eon

Definition: theory that states that natural disasters such as floods and volcanic eruptions shaped Earth's landforms and caused extinction of some species.

• catastrophism

• creationism

• neptunism

• plutonism

Definition: Just as eons are subdivided into eras, eras are subdivided into units of time called periods.

• precambrian time

• period (geologic time)

• relative age

• evolution