When a Billion Years Disappeared

What is the Great Unconformity?

• A supercontinent

• A continuous sequence of rock layers

• A gap in the geological record

• A type of sedimentary rock

How are sedimentary rock layers formed?

• By the accumulation of eroded materials

• Through the cooling of magma

• Through volcanic activity

• By tectonic plate movements

What is the Snowball Earth hypothesis?

• A concept related to the formation of the Grand Canyon

• A hypothesis about volcanic eruptions

• A theory about the formation of supercontinents

• The idea that Earth was once entirely covered in ice

Which supercontinent's breakup is linked to the Great Unconformity?

• Laurasia

• Pangaea

• Gondwana

• Rodinia

What does one hypothesis suggest about the relationship between Snowball Earth and the Great Unconformity?

• They are unrelated phenomena

• Both occurred simultaneously

• The Great Unconformity caused Snowball Earth

• Snowball Earth caused the Great Unconformity

What role did glaciers play in one hypothesis about the Great Unconformity?

• They created new supercontinents

• They formed new rock layers

• They eroded existing rock layers

• They caused volcanic eruptions

How might the Great Unconformity have influenced ocean chemistry?

• By increasing volcanic activity

• By transporting geologic material to the sea

• By causing tectonic shifts

• By altering the Earth's magnetic field

What elements were potentially introduced to the oceans due to the Great Unconformity?

• Gold and silver

• Calcium and phosphorus

• Helium and neon

• Nitrogen and oxygen

What process might have been encouraged by the new ocean chemistry?

• Volcanism

• Photosynthesis

• Biomineralization

• Erosion

What event is associated with the diversification of complex life?

• The extinction of dinosaurs

• The Ice Age

• The Cambrian Explosion

• The formation of Pangaea