Geologic History of Earth

Front

What are the three major eras of the Geologic Time Scale?

Back

Paleozoic, Mesozoic, Cenozoic.

Front

During which era did life first evolve on land?

Back

Paleozoic.

Front

What is the Law of Superposition?

Back

The principle that in undisturbed sedimentary rock layers, the oldest layers are at the bottom and the youngest are at the top.

Front

What does the term 'Paleozoic' refer to?

Back

An era in the Geologic Time Scale that lasted from about 541 to 252 million years ago, known for the development of early life forms.

Front

What is the significance of the Mesozoic Era?

Back

It is known as the age of reptiles, including dinosaurs, and lasted from about 252 to 66 million years ago.

Front

What does 'Cenozoic' mean?

Back

The most recent era in the Geologic Time Scale, starting 66 million years ago and continuing to the present, known for the rise of mammals.

Front

What is relative dating in geology?

Back

A method used to determine the age of rocks and fossils in relation to one another, without exact dates.

Front

What is an epoch in the context of geologic time?

Back

A subdivision of a period in the Geologic Time Scale, representing a specific time frame.

Front

What is the difference between a period and an era?

Back

An era is a larger division of geologic time that contains multiple periods.

Front

What is the purpose of the Geologic Time Scale?

Back

To provide a timeline for Earth's history and the evolution of life.