Geologic Time Part 1

Front

What gas became part of Earth's atmosphere mainly as a result of the evolution of life-forms?

Back

Oxygen

Front

What Eon experienced the accumulation of oxygen in the atmosphere?

Back

Proterozoic

Front

In which era did most creatures live in the ocean?

Back

Cambrian

Front

What is the current eon called?

Back

Phanerozoic

Front

What are the four main eons of geological time?

Back

Hadean, Archean, Proterozoic, Phanerozoic

Front

What significant event marks the beginning of the Phanerozoic eon?

Back

The Cambrian Explosion

Front

What is the significance of the Cambrian Explosion in Earth's history?

Back

It marks a rapid diversification of life forms and the appearance of most major animal phyla.

Front

What is the primary characteristic of the Proterozoic eon?

Back

The buildup of atmospheric oxygen and the emergence of multicellular life.

Front

What major geological events occurred during the Hadean eon?

Back

Formation of the Earth, differentiation of the core and mantle, and the formation of the Moon.

Front

What is the difference between the Archean and Proterozoic eons?

Back

The Archean eon is characterized by the formation of the first stable continental crust and the emergence of prokaryotic life, while the Proterozoic eon saw the accumulation of oxygen and the rise of multicellular organisms.