Exploring Earth's Geologic History and Time

How long ago was Earth formed?

• 4.6 million years ago

• 3.7 billion years ago

• 65 million years ago

• 4.6 billion years ago

What does relative time in geology indicate?

• The decay rate of uranium

• The chemical composition of rocks

• The sequence of events

• The exact age of rocks

Which element is used in carbon dating?

• Uranium

• Carbon-14

• Iridium

• Lead

What event is believed to have caused the extinction of dinosaurs?

• A volcanic eruption

• A meteorite impact

• A massive earthquake

• A global flood

How are fossils usually formed?

• By being quickly buried in sediment

• Through freezing in ice

• By petrification of wood only

• Through exposure to sunlight

What marks the beginning of the Paleozoic era?

• The extinction of dinosaurs

• The appearance of mammals

• The formation of the supercontinent Pangaea

• The Cambrian explosion

Which era is known as the age of dinosaurs?

• Precambrian

• Paleozoic

• Cenozoic

• Mesozoic

What significant event occurred at the end of the Mesozoic era?

• The Cambrian explosion

• The formation of the Grand Canyon

• The meteorite impact causing mass extinction

• The appearance of the first humans

Which era do we currently live in?

• Precambrian

• Paleozoic

• Cenozoic

• Mesozoic

When did the first human skeletons appear in the fossil record?

• About 200,000 years ago

• 500 million years ago

• 4.6 billion years ago

• 65 million years ago